Bare Knuckle Pickups Forum
Forum Ringside => Guitars, Amps and Effects => Topic started by: Twinfan on December 29, 2010, 04:18:23 PM
-
I've just picked it up from Sounds Great and given it a quick run through. Build quality seems pretty top notch and sturdy, the amp looks a million dollars and everything works as it should.
Power reduction/scaling works really well, at TV volumes you still get plenty of character and oomph. The amp does feel like it wants to be wound up to gig volumes though!
#34 mode is a lightly modded JCM800, and so it's quite clean, bright and twangy in my living room. I'm looking forward to trying it out at rehearsal as it's classic JCM800 - I think it needs the back end cooking to really shine.
AFD mode is what everyone's after from this amp, and it's very,very good. I've been playing some Bon Jovi, Skid Row and 90s Alice Cooper and it's got *that* hot-rodded Marshall thing going on. Very similar to the blue channel on my Bogner XTC Classic but brighter and a bit thicker. It reminds me a lot of Brow's Splawn. Oh, and it cleans up great on the volume too.
Overall? I think it's the best Marshall I've ever played. A classic.
Right, back to the playing.........!
-
Wow, cool!
CLIPS/VIDS!
-
I'll see if I can get something quickly done tomorrow and bung it on YouTube.....
-
OH NO! He raised that evil object from the darkness again!!!
Go back to the shadows, evil creature!
GAS :(
-
Nice one mate, can't wait to hear it.
-
Nice one Dave, sounds like a keeper! Look forward to more info and clips.
P.s Hope you had a good holiday (assuming you got there?????)
-
Cheers Don! I had a superb holiday thanks, didn't realise I'd mentioned it to anyone????
Here's a little teaser of where I went ;)
(http://sphotos.ak.fbcdn.net/hphotos-ak-ash2/hs473.ash2/74633_10150114919089363_691724362_7607196_4107658_n.jpg)
(http://sphotos.ak.fbcdn.net/hphotos-ak-ash1/hs752.ash1/164345_10150114919499363_691724362_7607217_4048881_n.jpg)
(http://sphotos.ak.fbcdn.net/hphotos-ak-snc4/hs1357.snc4/162904_10150114919349363_691724362_7607211_481755_n.jpg)
(http://sphotos.ak.fbcdn.net/hphotos-ak-snc4/hs1393.snc4/164570_10150114920094363_691724362_7607248_417792_n.jpg)
-
Dazza - I reckon you'd like the AFD ;)
-
Wow... not sure which I'd like more mate..... the AFD or the holiday! Been a few years since my better half, my kids and I had a decent break! Nice one. 8)
-
I was thinking of getting married there next year! Might quiz you about it in the not too distant future!
I also picked up a new amp from Sounds Great this morning.
They gave me a discount!!!
Mine was a Fender G-Dec 3 Thirty :o Going to be used in my hotel room whilst away for a while.
Does the AFD play backing tracks? Didn't think so!!! I win! :D
-
Sounds great Dave!
Looking forward to there being another forum day so I can possibly check it out :lol:
-
Oooohh.... that sounds very promising! :D
-
Cheers Don! I had a superb holiday thanks, didn't realise I'd mentioned it to anyone????
Here's a little teaser of where I went ;)
cool holiday Dave, yeah you mentioned it here :)
-
Congrats on both the amp and the holiday.
-
Cheers guys :)
Matt - IceHotel is incredible, just make sure you've got deep pockets - I think it's just about bankrupted me!
-
Cheers guys :)
Matt - IceHotel is incredible, just make sure you've got deep pockets - I think it's just about bankrupted me!
You could always sell the AFD!
Looking forward to hearing some clips - surely some classic GnR has to be played!
-
Other than Nighttrain - which you just HAVE to play on this amp - I don't know actually know much of Appetite :oops:
I can't wait to get Francine back from her holiday safe-keeping place and try her out through the AFD...
-
Congrats! Love the sound of these things from the promo videos, would be very interesting to check one out in person.
-
Other than Nighttrain - which you just HAVE to play on this amp - I don't know actually know much of Appetite :oops:
I only really know Nighttrain and Sweet Child. That is all.
-
Cheers Don! I had a superb holiday thanks, didn't realise I'd mentioned it to anyone????
Here's a little teaser of where I went ;)
(http://sphotos.ak.fbcdn.net/hphotos-ak-ash2/hs473.ash2/74633_10150114919089363_691724362_7607196_4107658_n.jpg)
(http://sphotos.ak.fbcdn.net/hphotos-ak-ash1/hs752.ash1/164345_10150114919499363_691724362_7607217_4048881_n.jpg)
(http://sphotos.ak.fbcdn.net/hphotos-ak-snc4/hs1357.snc4/162904_10150114919349363_691724362_7607211_481755_n.jpg)
(http://sphotos.ak.fbcdn.net/hphotos-ak-snc4/hs1393.snc4/164570_10150114920094363_691724362_7607248_417792_n.jpg)
Northern Ireland last week?
Seriously, though, looks cool. Nice score on the amp too. :)
-
Jealous of that hol...
-
sod the holiday, pass the amp over Dave, you've already got a Bogner!
-
Here's a very quick and dirty clip of the amp in my living room at loud TV volume on the AFD setting. I've got to say, it records great even on my basic Sony digital camera!
http://www.youtube.com/watch?v=LgdT1-HMDx8
-
That sounds great Dave.
Jealous.
-
Sounds really great - wish I had more room and loads of money
Maybe see if Egnater /Randall will clone it.....(althogh the Egnater Sl2x module used to be called the GNR)
-
Cheers guys. I mucked about with preamp valves before recording the clip and it now has:
V1: Marshall badged JJ (came in the amp in this position)
V2: Regular JJ
V3: Stock Shuguang Marshall
V4: Stock Shuguang Marshall
V5: Groove Tubes JJ
The two extra JJs have fattened the tone a touch which is nicer at lower volumes. Can't wait to crank it now, might get the chance on Monday...
-
That's really a great sound. Maybe this is one the best Marshalls ever made.
-
I seriously think it is, and it has the biasing technology and power scaling all in for £1199. That makes it great value for money in my book too.
At gig volumes it should sound amazing!
-
I seriously think it is, and it has the biasing technology and power scaling all in for £1199. That makes it great value for money in my book too.
Watching that clip, I tend to agree!
-
Imagine how good it sounds a) recorded properly and b) with a great player!
It "feels" good too, even though the insides suggest it might not...
(http://www.tonymckenzie.com/Site/images/pimages/board1_large.jpg)
-
Considering the price, it is actually a bargain with boutique tone.
-
I certainly think so - it's the best Marshall for a looooooooong time.
-
Imagine how good it sounds a) recorded properly and b) with a great player!
It "feels" good too, even though the insides suggest it might not...
(http://www.tonymckenzie.com/Site/images/pimages/board1_large.jpg)
Ah - pic by Tony Mckenzie - that's who I bought my Randall Lynch-box from (although it proved a bit too loud /large for my uses)
-
sounds good :)
-
Here's a very quick and dirty clip of the amp in my living room at loud TV volume on the AFD setting. I've got to say, it records great even on my basic Sony digital camera!
http://www.youtube.com/watch?v=LgdT1-HMDx8
Classic rock heaven. Very cool.
-
congrats,lovely sounding amp and very tempting with the power scaling. my worry would be long term the glitches
may start appearing and no doubt difficult to put right looking at the inner complexity.
it will be interesting to see how it's viewed in 3 or 4 years time being a new model.
-
I played one of the demo units a while ago, and it sounded good, but didn't blow me away completely-- obviously being in a big exhibition hall meant that I couldn't crank it, but the power scaling seemed to sound just like the master volume at low levels. The guy supervising the amp also didn't know anything about it, including what the AFD switch was (told me it was the power scaling)... so it may have not been a final model. It sure did sound like AFD though, which was great :)
-
Congrats on the amp it sounds very nice.
Cheers for doing the demo.
First picture I saw I wondered had you just stayed at home. Anyway hope it was a good holiday.
(http://sphotos.ak.fbcdn.net/hphotos-ak-ash2/hs473.ash2/74633_10150114919089363_691724362_7607196_4107658_n.jpg)
-
Can you Play death metal? Do a clip where you play some brutal stuff on it :D I really wanna hear it.
And if you go and play "Brutal" djent then ill cry. Dont make me cry :(
-
Sounds good Dave :) Haven't had amp gas for a long time but this is intriguing.
-
Twinfan, I liked that sound in the clip, but what really caught my attention was that guitar you were playing! 8) Nice one! May I ask what make that is?
-
Nice amp. It's got some interesting features. :D
-
Alex - here's the guitar I was playing, it's a Paul Richardson SCR:
http://www.bareknucklepickups.co.uk/forum/index.php?topic=20602
-
Now you need a setup like me with the switcher, so you can run a clean sound as well as full on overdrive.
-
Who needs a clean sound???? :lol:
Rolling back the volume "old skool" is good enough for me...
-
Who needs a clean sound???? :lol:
Rolling back the volume "old skool" is good enough for me...
If I had that amp and all your gear, I'd just get a White Baby Grand Piano to play in the tender moments.. (and to stand on for the big solo of course) :lol:
Looks like a great amp.
-
Very nice Dave, so the speakers were Golds and G12H's.... in an X pattern?
-
Yep, they're the ones Don :)
Quick update on the amp, as it looks like I have the first "broken" AFD100 :(
Volume started swelling up and down, and now V1 has the bias error light on. Tried several different valves in V1 and every one shows an error. Must be something specific to the V1 power supply. Damn.
It's going back to Sounds Great on Tuesday. Arse.
-
No!!! :o :o
Seem like it's got an Appetite For (self) Destruction :?
-
How very annoying - hope it's not a serious problem and that you get it back soon.
-
Maybe there's a bug in the firmware :lol:
Sorry Dave, surely it's gonna be fixed soon. Have you checked all fuses?
All good luck with it!
-
don't worry. I found sounds great to be top notch when fixing things under warranty. oh wait!
nah they probably value you your custom enough to not treat you like a chump and send you a repair job done by a one armed, blind, chimp.
-
Maybe there's a bug in the firmware :lol:
:lol: :lol: :lol:
sorry your new toy is broken though dave, best of luck getting it fixed
-
You poor soul, you'll just have to go make do with a Bogner! :lol:
Seriously though, it sucks but Marshall after sales is second to none from what I've heard so I'm sure you'll have it back in full working order real soon.
-
Yep, it's a bugger but it's all warrantied for 12 months, and 3 years if I send back the warranty card (which of course I'll definitely be doing!)
I hope it's not the first of many and just an isolated incident...
-
if possible will you let us know what happened? I for one would perhaps be interested.
-
I'll update this thread, yes. I doubt I'll have the same experience you had.
-
Oh I didn't ever think you would.
I just wondered about what fault happened with the amp. I'd be interested to know that.
-
That's a bummer Dave :(
Hope it's sorted soon and has no more issues.
-
Alreet Dave mate happy new year or not as the case may be what a sickener about the amp sorry to hear about that it sounds great on the Youtube clip,anyway hope its sorted quickly. cheers
keith
-
How shite is that!
Sounds Great have been really good recently so let's hope they can fix it pretty quick.
Seen as the Bogner isn't power scaled, you will need a practice amp.
You can swap it in exchange for my new G-dec in the short term.................. just give me a call :)
-
How shitee is that!
Sounds Great have been really good recently so let's hope they can fix it pretty quick.
Seen as the Bogner isn't power scaled, you will need a practice amp.
You can swap it in exchange for my new G-dec in the short term.................. just give me a call :)
:D
HOw is the g-dec? I'd like to hear some clips (serious)
-
Cheers Matt - lovely offer :lol:
Can't quite believe the AFD100 as bust to be honest, but Marshall won't want it staying broken for long ;)
-
i feel for you..at least it's under warranty.
-
How shiteee is that!
Sounds Great have been really good recently so let's hope they can fix it pretty quick.
Seen as the Bogner isn't power scaled, you will need a practice amp.
You can swap it in exchange for my new G-dec in the short term.................. just give me a call :)
:D
HOw is the g-dec? I'd like to hear some clips (serious)
It's a step down from my normal set-up, but it's very mobile. I'm getting the footswitch later in the week so if I get the chance, I'll start a new thread with a review later in the week
-
Well the AFD100 has just been dropped off for repair. Sounds Great said they would have swapped it there and then for another of their allocation of 3, but they'd been sold - one to Oz and one to Italy!
It's going back to Marshall...
-
dang that sucks :(
-
That's an arse about the amp.
Buy yourself a guitar, it'll make you feel better.
-
Cheers Matt - would appreciate that.
Dave - hope you get it back soon! I'm wondering if Marshall will do a speedy turnaround on it seeing as it is their latest big/flagship amp.
-
I was wondering the same thing! :lol: They're supposed to be pretty quick with warranty claims anyway so I'd hope to have it back by the end of next week?
-
That sucks!
Do you still have your MJW? At least that seems to have never failed you.
-
Hope it will be back soon.
-
That sucks!
Do you still have your MJW? At least that seems to have never failed you.
I've just got my JTM45/100 now.
The MJW Orion was faultless the whole time I had it, but the JTM45 blew two mains transformers - both Ceriatone ones and clear component failures. Martin refuses to use Nik's transformers any more as he had quite a few fail on him.
The JTM45/100 transformers have been replaced with Metroamp ones (same as fitted in my old Orion) as a preventative measure...
-
That sucks!
Do you still have your MJW? At least that seems to have never failed you.
I've just got my JTM45/100 now.
The MJW Orion was faultless the whole time I had it, but the JTM45 blew two mains transformers - both Ceriatone ones and clear component failures. Martin refuses to use Nik's transformers any more as he had quite a few fail on him.
The JTM45/100 transformers have been replaced with Metroamp ones (same as fitted in my old Orion) as a preventative measure...
Hmm, ive had a ceriatone transformer go on me too in my plexi clone
-
Quick update for everyone. I've had a call to say my AFD100 is back at Sounds Great from being repaired at Marshall. That's a pretty darn good turnaround - I dropped it off last Tuesday afternoon, so that's ony one week :)
I can't get there to pick it up today, so tomorrow night will be testing night ;)
-
Fingers crossed they've fixed it properly!
-
That's good news. :)
-
Quick update for everyone. I've had a call to say my AFD100 is back at Sounds Great from being repaired at Marshall. That's a pretty darn good turnaround - I dropped it off last Tuesday afternoon, so that's ony one week :)
I can't get there to pick it up today, so tomorrow night will be testing night ;)
Wow ! That's really impressive !Great 8)!
-
Well I picked the amp up yesterday, and the biasing is now working fine which is good! But the volume wobbling was still there :?
At the suggestion of Mrs Twinfan, I've just spoken to Marshall tech support and the actual guy who repaired it. How cool am I? :lol:
The bias problem was a resistor that had blown, caused by me putting some cr@ppy valves in (whoops!). The volume wobbling *may* be that I've got the power control on a crossover point, and moving it slightly up or down will cure it. It's not a liner 'pot' as such, but a digital control that might be between triggers. I need to get it happening again and raise or lower the power setting and see if it goes away. Something to try over the weekend.
So I've got to say top marks to Marshall for the customer service, excellent so far!
-
So... who is going to get the new Malmsteen Model?
http://www.namm.org/files/presskits/MarshallNAMM2011.pdf
-
Not me!
-
So... who is going to get the new Malmsteen Model?
http://www.namm.org/files/presskits/MarshallNAMM2011.pdf
Is it the YJM100 or JYM100?
Their proofreader needs a Red Bull!
-
The volume wobbling *may* be that I've got the power control on a crossover point, and moving it slightly up or down will cure it. It's not a liner 'pot' as such, but a digital control that might be between triggers. I need to get it happening again and raise or lower the power setting and see if it goes away.
Tried it, and it still does it. You move the pot and it's OK again for a bit then it wobbles again.
Back to Marshall - double arse!
-
The volume wobbling *may* be that I've got the power control on a crossover point, and moving it slightly up or down will cure it. It's not a liner 'pot' as such, but a digital control that might be between triggers. I need to get it happening again and raise or lower the power setting and see if it goes away.
Tried it, and it still does it. You move the pot and it's OK again for a bit then it wobbles again.
Back to Marshall - double arse!
That totally sucks. Unbelievable!
-
So... who is going to get the new Malmsteen Model?
http://www.namm.org/files/presskits/MarshallNAMM2011.pdf
If I had money kicking about I'd probably buy one. Plexi with an overdrive in front is THE sound for hellish mid-grind extreme metal. In my book, anyroads. Plus it's barely got any Yngwie livery, not like the stupid Kerry King head or the Slash nonsense on the AFD100, both of which are amps I'd consider buying, otherwise.
-
So... who is going to get the new Malmsteen Model?
http://www.namm.org/files/presskits/MarshallNAMM2011.pdf
If I had money kicking about I'd probably buy one. Plexi with an overdrive in front is THE sound for hellish mid-grind extreme metal. In my book, anyroads. Plus it's barely got any Yngwie livery, not like the stupid Kerry King head or the Slash nonsense on the AFD100, both of which are amps I'd consider buying, otherwise.
However, wouldn't the true Yngwie sound be a 50W instead of a 100W?
-
So... who is going to get the new Malmsteen Model?
http://www.namm.org/files/presskits/MarshallNAMM2011.pdf
If I had money kicking about I'd probably buy one. Plexi with an overdrive in front is THE sound for hellish mid-grind extreme metal. In my book, anyroads. Plus it's barely got any Yngwie livery, not like the stupid Kerry King head or the Slash nonsense on the AFD100, both of which are amps I'd consider buying, otherwise.
However, wouldn't the true Yngwie sound be a 50W instead of a 100W?
:lol: You beat me to it! Yngwie definitely prefers the 50 watter.
Edit: It does have a switch to half the power though. :P
-
Tried it, and it still does it. You move the pot and it's OK again for a bit then it wobbles again.
Back to Marshall - double arse!
dang, that's bound to be annoying :(
-
It is!
Ah well, that's what warranties are for I guess!
-
Perhaps they can put that feature on the Yngwie amp. It emulates his volume swells for you.
-
It's not a liner 'pot' as such, but a digital control...
i'm all for being progressive technichally, but this sounds just wrong to me
So I've got to say top marks to Marshall for the customer service, excellent so far!
i agree, marshall have always been top notch in my dealings with them, and quite reasonably priced too
-
that sucks, man.
Didn't know the volume was a digital control.
I wonder if Marshall just swapped a PCB. heard of anyone else having a problem?
(purely speculation) the work they do to yours might end up being in later runs and you'll be part of the development... in a way.
-
the Yngwie amp looks great - a plexi with power scaling, effects loop and a foot-switchable boost in the front end.
whats NOT to like about that? - sounds like Marshall have put into place some improvements which encompass all the usual things that people bitch about when playing the old non-master volume Marshalls.
-
the Yngwie amp looks great - a plexi with power scaling, effects loop and a foot-switchable boost in the front end.
whats NOT to like about that? - sounds like Marshall have put into place some improvements which encompass all the usual things that people bitch about when playing the old non-master volume Marshalls.
i was looking a the specs and thinking it was quite a sensible design too. classic good looks as well.
i wonder what the prices will be like.
-
the Yngwie amp looks great - a plexi with power scaling, effects loop and a foot-switchable boost in the front end.
whats NOT to like about that? - sounds like Marshall have put into place some improvements which encompass all the usual things that people bitch about when playing the old non-master volume Marshalls.
i was looking a the specs and thinking it was quite a sensible design too. classic good looks as well.
i wonder what the prices will be like.
can't imagine they'll be any more expensive than the AFD100.
-
Depends how much Yngwie wants :roll:
-
Depends how much Yngwie wants :roll:
Have pies gone up much lately ?
-
If I had money kicking about I'd probably buy one. Plexi with an overdrive in front is THE sound for hellish mid-grind extreme metal. In my book, anyroads. Plus it's barely got any Yngwie livery, not like the stupid Kerry King head or the Slash nonsense on the AFD100, both of which are amps I'd consider buying, otherwise.
Hey, the Kerry King model is awesome!
-
If I had money kicking about I'd probably buy one. Plexi with an overdrive in front is THE sound for hellish mid-grind extreme metal. In my book, anyroads. Plus it's barely got any Yngwie livery, not like the stupid Kerry King head or the Slash nonsense on the AFD100, both of which are amps I'd consider buying, otherwise.
Hey, the Kerry King model is awesome!
i've liked the clips i've heard - but those tribal graphics are in doubtful taste IMO
-
Depends how much Yngwie wants :roll:
Have pies gone up much lately ?
looks like he's been eating his amps nevermind pies.
-
If I had money kicking about I'd probably buy one. Plexi with an overdrive in front is THE sound for hellish mid-grind extreme metal. In my book, anyroads. Plus it's barely got any Yngwie livery, not like the stupid Kerry King head or the Slash nonsense on the AFD100, both of which are amps I'd consider buying, otherwise.
Hey, the Kerry King model is awesome!
i've liked the clips i've heard - but those tribal graphics are in doubtful taste IMO
Doubtful, but rather inobstrusive IMO.
-
If I had money kicking about I'd probably buy one. Plexi with an overdrive in front is THE sound for hellish mid-grind extreme metal. In my book, anyroads. Plus it's barely got any Yngwie livery, not like the stupid Kerry King head or the Slash nonsense on the AFD100, both of which are amps I'd consider buying, otherwise.
Hey, the Kerry King model is awesome!
i've liked the clips i've heard - but those tribal graphics are in doubtful taste IMO
Doubtful, but rather inobstrusive IMO.
Unobtrusive!? They're caked all over the front of it. Otherwise yes, cool amp. Likewise the Slash one, though the graphics aren't as rotten, the silly Slash picture/logo thing is still honking.
-
Yeah, 'coz the logos make 'em sound cr@p :roll:
-
Yeah, that's exactly what I was saying.
-
they should do a limited edition run in purple, because we all know that purple amps sound best :lol:
-
Only if you have a green guitar plugged in it
-
Well I've just dropped the AFD100 back at Sounds Great, it'll be heading back to Marshall today. It seems to be the Power Scaling that's on the blink, with random volume fluctuations when it's dialled in. Wound out on full power, just using the Master Volume it's REALLY noisy - proper hissing.
I used it at rehearsal last night and at times it sounded really good, but it's definitely a one trick pony. A great, great rock amp. Looking forward to getting it back again, and hopefully fixed this time!
-
Mine is doing exactly the same thing :?
I plug it in, it sounds great then the volume starts going up and down. At some point it suddenly sounds loud and very shrill.
Took it back to Marshall ( I live reasonably near) they fiddled around with it, replaced some tubes and set it up for me. Plugged in and it sounded great. Took it home. plugged in and it still sounded great. Suddenly the volume starts going up and down again then the tone turns to sh*t.
Tried a different guitar, different leads, different mains lead. No better. Anyway my other amp with the same kit doesn't do it.
Marshall gave me a shipping number and it was sent back by local courier. That was Tuesday, today is Sunday. I found a guy on youtube who had the power control replaced because of the same thing. So that's 3 of us...
I'm not bashing Marshall, they are IT as far as I'm concerned but this is getting annoying. It's not as though it's a cheap amp. My Dad always used to say 'never buy the mark one version of anything'......
-
Wonder if Slash has had any problems!
-
Maybe Slash doesn't use the power scaling...
-
I know he has 2 amps running on stage plus a spare.....
-
So that's three of us! :o
Mine came back from Marshall twice with the same fault they said they couldn't replicate. I've used it at home a few times since, and at rehearsal, and it's behaved itself perfectly. There's clearly some sort of intermittent fault, and I think it's related to the biasing procedure.
I'm watching mine for a bit to see how it gets on before sending it back for trip number 3...
-
I know he has 2 amps running on stage plus a spare.....
and probably half a dozen techs after they read the BKP Forum about the problems Dave has been having
-
My money (not that I have any now....) is on the power scaling pot or circuit. I tried different tubes in mine before I sent it back and I re-biased it several times. Worked perfectly every time.
If I knew the first thing about electronics (which I don't) I'd say the pot or circuit were leaking current somehow. The change in tone in mine is really apparent when it starts playing up. If you've ever had a loose connection on a guitar pot and suddenly the thing sounds really tinny that's the effect I'm getting.
If I get it back with the 'sorry we couldn't replicate the problem' message I'm going to be cross.
-
You've got the same issue as mine dude :(
I don't think it's the pot. I spoke with a Marshall tech the first time it went back and the power control is more of a "trigger" for the increments in power, not an infinitely variable pot. If you look in the manual you'll see the power levels with fixed trigger points.
My guess is that as the amp gets warm the resistance track of the pot changes a little and it ends up on the cusp of a trigger point, dropping to the next point down. It seems to be when the power is around 8:30 to 9:00 o'clock on mine - same with yours?
-
Yep. Well to be honest I haven't tried it any louder. I expected to be able to get a hot tone in the house as well as at gigs/rehearsals - that's the reason I chose the amp. I'm not a Slash worshipper - I just want a good reliable hotrod Marshall and this amp ticked all the boxes.
Does the tone change on yours when it plays up - mine goes really ice-picky :(
-
I'm not bashing Marshall, they are IT as far as I'm concerned but this is getting annoying. It's not as though it's a cheap amp. My Dad always used to say 'never buy the mark one version of anything'......
+1
I remember we all had a chat about the bias technology with relation to the hughes & kettner maybe? I've read and seen information about Orange using it too, and also making a standalone auto-bias unit to retro fit older amps. the DIVO I think.
If this unit is used for the 'power scaling' (as far as I understand the term power scaling is a trademark of London Power and relates to a particular method of power reduction which I think you should pay a fee to use) then that might make sense. I guess the pot is triggering some digital device registering the resistance changes in steps. maybe its something else and not that bias engine.
I'm not sure about the pot getting so hot the resistance changes. Most pots have a pretty big tolerance. +/- 20% for example. I'd imagine the steps in power are arranged in a way that would make it really hard for you to get bang on half way between.
anyway. its all really interesting. sorry about your amps though.
-
I'd imagine the steps in power are arranged in a way that would make it really hard for you to get bang on half way between.
I'm not sure it is, as I reckon that's the issue....
-
When the amp is on you can feel a 'step' as the power control goes from one level to the next so I imagine it's more of a rotary switch than a pot as such.
I still don't think it's to do with the bias thingy because the first time it went wrong I immediately re-biased it to make sure. No difference. Also I'm sure we all know that bias can change quite a bit on a regular amp without making a sudden noticeable difference. Besides if there's a bias problem it's supposed to flash to let you know. Mine hasn't flashed.
I'm sure the voltage in my house varies from in the day when no-one is using much juice to the evening when everyone has the telly and the PCs and lights on. On my other amp (which is a 50watt handwired plexi clone with external bias points) I can hear a subtle difference but it's nothing like this. Anyway reducing the input voltage is a way to get a 'browner' sound - people have been using variacs to achieve this for years. In this case the sound is going thin so I doubt it's a fluctuating voltage issue.
Interesting point though - I don't have a way to measure the voltage coming out of the wall. Anyway the problem is random - day, evening - any old time. I'm not happy to use the amp at a gig though. Which makes the whole thing start to look a bit pointless unless someone can say categorically that the problem is <this> and we've done <this> to fix it.
I go to a local jam where the backline kit is all Fender. If I take this down there and it plays up I can just imagine the jeers from the Fender benders.....
-
It'll be a bit odd if the amp is that sensitive to voltage fluctuations won't it?
I rehearsed with mine last week (in an old mill with what must be cr@p wiring) with no issue, and I'll be taking it again tomorrow night.
Mine hasn't played up for a little while, which is strange...
-
I'd imagine the steps in power are arranged in a way that would make it really hard for you to get bang on half way between.
I'm not sure it is, as I reckon that's the issue....
does this problem happen wherever you set the power level though? Like every time you set it, eventually you get this issue. Indicating that every time you dial it in you hit a half way point?
I'm just speculating because I'm interested.
As for input voltage, I wouldn't have thought it would vary by much more than +/- 20VAC? I've seen a small UPS used in a hotel to run a server that generated a input voltage graph against time. I had a friend who used one in his house as a power conditioner because his TSL kept needing repairs and it was another thing to try and fix it. He thought he had too much input AC.
You can get bias modulating tremolo effects. I was wondering if something like that might be going on.
-
Interesting point though - I don't have a way to measure the voltage coming out of the wall. Anyway the problem is random - day, evening - any old time. I'm not happy to use the amp at a gig though. Which makes the whole thing start to look a bit pointless unless someone can say categorically that the problem is <this> and we've done <this> to fix it.
Give me four grand and I'll get the whole neigbourhood studied for you. I can tell you short term and long term voltage flicker, harmonic levels (which could actually be an issue with amps), all sorts really :lol:. When I'm seeing the boffin next, I'll see if harmonics could be affecting the amps. Does the problem happen at consistant times?
Dmoney - Fairly sure that the UK is now 230V (+10% - 5%). It used to be 240V (+5% - 5%) but we changed it to be in line with Europe....... as you can see, we didn't actually do anything, just fiddled the numbers a bit :D
-
I was just going off that UPS I used to see. I couldn't remember what the peak was but I was just thinking 240v was average and 20volts either side of that seemed reasonable from memory. 240 + 5% is 252... so I wasn't far off :)
-
does this problem happen wherever you set the power level though? Like every time you set it, eventually you get this issue. Indicating that every time you dial it in you hit a half way point?
I'm just speculating because I'm interested.
Nope - there seems to be a particular point on mine around 8:30 to 9:00 on the dial, which is home TV levels. It only seems to happen on the quiter setting, so maybe it's one particular point that it's easy to get stuck halfway on?
-
Are you using it at house level - i.e. in the 8.30 - 9 area? It's happened to me anywhere between fully down - 7 o clock and 9 o clock which is the next 'step'. If it's playing up it's really loud at 9 o clock even though that's supposed to be 1 watt. Like much too loud to use in the house. I know Marshall watts are bigger but...
When I got it back I was playing it at 9 o clock and it went from loud-ish to almost inaudible. I kept playing in the hope that something would break and identify itself but it came up again then went really loud and nasty sounding. That was the last time I used it.
I found a study that someone had done of power fluctuations in the national grid over a period of a week and they weren't very much. Average 230v which is right on the money, occasional short spikes up to 240 max and very occasional lows of 226 I think. Lost it now. I doubt that's it.
Twinfan on your youtube clip where have you got the master and the power control?
-
On that clip, power is about 9:00 and master around 6-7 I think - that's my usual home setting. It's been really stable there recently, but it has been awful on that setting.
It's a really odd issue isn't it? if mine starts playing up again, I'll certainly be mentioning the fact that I'm not the only one!
-
I found a study that someone had done of power fluctuations in the national grid over a period of a week and they weren't very much. Average 230v which is right on the money, occasional short spikes up to 240 max and very occasional lows of 226 I think. Lost it now. I doubt that's it.
It very much depends where you live and what's connected to your local network. If you have a lot of industry on the same circuit (any of them from 66kV down really) then the issues can be quite apparent. There are planning and compatability levels for voltage flicker and harmonics etc which should always be adhered to by industrial users, but this isn't always the case as they can often buy a new machine and plug it in without realising that it's a disturbing load. This causes things to go what is technically described as "tits up" :lol:
Personally I think it sounds like an issue with the amp(s) rather than the supply as the above happening for three different people is highly unlikely. I'm still going to ask the boffins though as I'm curious more than anything else (although they cost over £150 an hour - each :o, so it will have to wait until I have a meeting about something else).
As someone suggested (quite rightly) in another thread, have you tried kicking it?
-
There's no industry in the area. I haven't kicked it yet but.......
-
I haven't kicked it yet but.......
maybe this should apply to someone at Marshall
-
At Marshall, they probably have the same procedure for dealing with issues as we have at the company I work for (pro audio). There is a standard bench test which tests out the functionality of the amp, and if it passes this, it is deemed as 'working', as it meets the predefined standards set for the product. Unfortunately, these tests sometimes don't catch anything (ie, we have a product where a control is tested at it's maximum and minimum values.... but I've had one returned which were within tolerance, but the value in the middle was way out of spec)... i'm sure it's something like this, where on the bench it works fine, but when used in a 'real world' situation, there is something amiss. I'm sure that Marshall will take more notice when the same amp returns again-- especially on a limited run of units.
-
They claimed they play tested mine quite a bit, not just a bench test. Mine was playing up a bit tonight but then sorted itself out.
I'm way confused :?
-
Get it back there Dave. Maybe even get it shipped via Sounds Great and email Marshall direct with your serial number saying that you know other people having the same problem, and If it comes back faulty again then obviously it's going to upset you, but If it happens to other people It's going to reflect badly on Marshall, maybe even effect sales of the YJM.
I dunno. I don't mean hold them to ransom with threats of trolling ( ? ) or whatever... I'm sure you get what I mean. A gentle nudge.
By rights you're now entitled to a full refund, since the repair job isn't up to scratch, but I can tell you'd rather have a working amp.
-
On a new amp I'm pretty sure they would have to give you the money back if it keeps having problems. UK law says no, but EU says yes to that. It is a bit tricky though and will take some convincing. Still, by now that is probably what I'd go for: return it.
-
On a new amp I'm pretty sure they would have to give you the money back if it keeps having problems. UK law says no, but EU says yes to that. It is a bit tricky though and will take some convincing. Still, by now that is probably what I'd go for: return it.
I thought UK law said yes. At least it did when I checked with CAB over Sounds Great outsourcing a repair job on my Soldano which came back to me messed up.
The supplier (whoever that is) get one shot at fixing it or replacing it, and if it doesn't work then you are entitled to a full refund. In this case that would come from Sounds Great. You can't keep on being forced to take poor repair job, after poor repair job.
-
you got handed a lemon. Get your money back or a full credit. That thing is dogsh*t.
-
My take - it's a bunch of components. One of them is playing up. It can be replaced. I don't want my money back or another amp. I just want this great amp to work properly so's I can go gig with it. At the moment I can't - well I don't have it but unless a problem is diagnosed and fixed I won't feel confident doing so. Where does that leave me?
Marshall are the bedrock of reliable, working, gigging kit - I just want reliable working gigging kit.
-
(http://Marshall are the bedrock of reliable, working, gigging kit - I just want reliable working gigging kit.)
Maybe the bedrock, but whether that has been continued... I'm not so sure. I've had Marshall's with bad reps hold up to some bad things, but then I have friend who constantly have TSL's and DSL's (for example) in for repair.
I feel bad for you... like you say... you want the amp the work, but there has to be a point where it either gets fixed, or you have to give up. Obviously that point is totally down to you.
-
Yep. I have to say I had a TSL for years and years without even a blip. 100% perfect reliability. I didn't turn it on once for 2 years and it was still perfect next time I used it.
We'll just have to see what Marshall find. Hopefully something.
-
does the amp work fine with the power scaling turned all the way off (i.e. no power scaling) ????
if so, I'd tend to err on the side of living with the amp and just using the master volume (IF you really love the amp and want to keep it).
my take is that Marshall should've sorted this before release - surely this must've come up during testing if there are two people on this board with the same issues.
-
Yep, it works fine with the power on full - I tested that myself. Sounds dead thin though, you need some power amp beef in a JCM800 at lower volumes!
-
Yep, it works fine with the power on full - I tested that myself. Sounds dead thin though, you need some power amp beef in a JCM800 at lower volumes!
agreed - JCM800s need VOLUME.
still, its a stage amp, so thats fair enough.
how you get it sorted.
-
it sounds like a relatively common embedded firmware bug you get when sampling the value of pots. obviously the resistances changes over time, due to temperature, dust and vibration. if it is on the edge of a certain key value, you can get oscillation between the two - which is twinfan's theory.
its a classic problem, and i've seen it myself. its solveable by adding some hysteresis into the system - a bit like with an analogue thermostat. you can also take a moving average - or do both.
of course it may not be the cause.
-
Yep, it works fine with the power on full - I tested that myself. Sounds dead thin though, you need some power amp beef in a JCM800 at lower volumes!
That is the problem precisely. I could live with the volume wobbling about a bit if it didn't sound so tinny with it. The posts you see on youtube, the guitarist magazine review and Marshall's own vids have a really ballsy sound - as did the one I tried in the shop. If the one I tried sounded like mine I'd have run like a thief.
I found another guy on the Marshall amps forum who isn't happy with his.
-
purpleplexi - I'll send you a PM. We need to sort this out.
Dave
-
purpleplexi - I'll send you a PM. We need to sort this out.
Dave
class action PDT_003
-
See this thread on the Marshall amps forum
http://www.marshallforum.com/marshall-amps/23918-afd100-problem-help.html
-
As far I understand with the "Power Scaling", Marshall refused to pay the London Power licencing fee ($5 an amp), and seem to have "developed" their own system.
From reading this thread, it seems they are using some form of DAC to code the changes in power level.
Kevin O'Conner outlined how to do this in one of the Ultimate Tone series (TUT4 or 6, I can't remember), although I'm not sure whether the circuit shown was an example of a "tried-and-trusted" circuit, or entirely theoretical.
Regardless, I remember thinking that at the time that this seemed a rather complicated method of controlling the power output of the amp, which lets face it doesn't need to be that accurate (we've managed to cope with inaccurate volume controls on guitar amps for at least 75 years!).
Now it would be an astonishing co-incidence if Marshall, given that they were already looking at London Power circuits, completely independently came up with the digital method of controlling the power output.
Sadly it looks like it has bitten them on the back side, some what.
-
Hummm good to see you guys are summing strenghts... I'm completely choked that Marshall did it... Man, it's a celebration model, few units, BIG money and it doesn't work? Come on....
Hope you guys get it sorted!!!!
BTW, some amps comes with a schematic of it, does this AFD100 comes?
-
Nope - no schematic Fernando.
I've subscribed to the Marshall forum so there's now at least three of us there with an issue. Not good for Marshall is it?
-
Not good at all!
-
Nope - no schematic Fernando.
I've subscribed to the Marshall forum so there's now at least three of us there with an issue. Not good for Marshall is it?
Indeed not good.
From what gwEm says, sounds like it is a well-known problem with this sort technology, which would suggest that Marshall don't understand it fully.
I've logged into the "super secret" Marshall schematic service facility and there's no schematic there. I expect there won't be until it goes out of warranty.
Regarding the "Power Scaling", what I have gleaned is that the screen grid voltage and bias voltages are varied, rather than the plate, screen and bias voltages, and that this is controlled by some digital which has a number of stepped power levels, and this seems to be where the problem is.
As ever, using "cutting edge" approaches often reveals unexpected problems.
-
Well the amp's designer, Santiago, has joined the Marshall Amps forum and basically accused of whining :roll:
If my fault wasn't intermittent I would have sent it back by now. I'm trying to find a setting that triggers it to happen ALL the time so I can go to the factory and demo it.
-
Well the amp's designer, Santiago, has joined the Marshall Amps forum and basically accused of whining :roll:
His response was remarkably unhelpful!
-
got a link to the marshall forum post? that's pretty uncool
-
The link to the thread is on page 10, here's the link to "Santiall" who is Santiago of Marshall:
http://www.marshallforum.com/marshall-amps/23918-afd100-problem-help-2.html#post314211
What part of "we've sent them back but Marshall fob us off that's nothing wrong" doesn't he undersatnd? :?
-
yeah stop yer whining, dave, what do you expect from a £1200 amp, for it to work all the time? It's certainly unfair, on an amp of that price, to expect them to cough up a whole $5 per amp (assuming what jpf said was correct, and I see no reason to suspect it's not) for a powerscaling system which is actually known to work.
:lol:
-
What a idiot!
-
Wow!
I just read it!
I mean... it defo got back to marshall? Sounds Great didn't just send it elsewhere?
as much as I dislike that company, I doubt they'd do that.
What if you put masking tape around the knob, then you could draw a little mark to line up the pot exactly to create the problem? might help if you need to get it spot on to recreate the fault?
It blows my mind that the designer signed up and came out with that. That alone is bad PR for marshall. Essentially accusing you all of making up the problem. You guys should all meet up and head down to Marshall HQ for a sit in!
-
The link to the thread is on page 10, here's the link to "Santiall" who is Santiago of Marshall:
http://www.marshallforum.com/marshall-amps/23918-afd100-problem-help-2.html#post314211
What part of "we've sent them back but Marshall fob us off that's nothing wrong" doesn't he undersatnd? :?
if he worked for me I'd have banned him from posting on the company forum - he's not exactly a brand ambassador is he :roll:
this needs sorted, but I can see why Marshall are denying anything is wrong - they don't want to create a scare, y'know - a few have the same fault, so they all must (AAAARRHHHH!!!!!!)
it'd be a shame if this can't be sorted, its a nice sounding amp.
-
I'd like to see him say that to your faces. What a tw@t.
Dave, when you go down to take it back can I come with you to watch. I'll eat some special curries so I can pass comment when required.
-
I'd like to see him say that to your faces. What a tw@t.
Dave, when you go down to take it back can I come with you to watch. I'll eat some special curries so I can pass comment when required.
I'll come too. It'll be like the Egyptian protests but with guitars and amps. way more rockin'!
-
I wouldn't feel so bad if someone had said - 'well there might be an issue with the power control so we've stuck a new one in. Take it away and try it for a week' but to just keep saying they've tested it and there's nothing wrong solves nothing.
They can put as many meters on it as they want but I reckon I've been playing the guitar longer than that guy has been alive. If my ears tell me it ain't right then it ain't right.
-
this needs sorted, but I can see why Marshall are denying anything is wrong - they don't want to create a scare, y'know - a few have the same fault, so they all must (AAAARRHHHH!!!!!!)
Realistically the more this goes on the worse it gets for Marshall which is not what I want. I've owned several Marshalls, I've used their service department because I live quite near and they've always been great. Ironically after the last amp (the one that blew spectacularly up) a big reason I went for this one was that I've never had an unreliable Marshall - new or used - and I knew that living nearby would enable me to get any issues resolved quickly and easily.
The guitar Gods must be laughing their asses off.
-
you should be entitled to a replacement right? under consumer rights legislation? If you'd had it back and the repair job wasn't up to scratch I'm pretty sure you can make a claim for a full refund (I went through this with my Soldano) but you'd have better luck getting a replacement.
4/1000 have failed that you know off... still good odds on getting a good one?
-
I'm not sure they'll honour a refund/replacement if they won't recognise that there's fault?
My amp definitely went to Marshall - I spoke to the repair tech who worked on it the first time, and the second time I spoke with the customer returns lady twice.
Purpleplexi - when are you supposed to be getting yours back?
-
What a total dildo for responding like that. Even someone with very little experience of dealing with customers would have come up with something more considered that. Im assuming he's got the hump as his design/expertise is being called into question.
Have you considered writing a complaint about it? I would think about it. My method of complaining is quite basic. If I don't get what I believe is correct/reasonable after my first letter I write straight to the CEOs office. Has worked a treat every time I have used it.
-
man...
sounds like a nightmare.
maybe there is a local authorized repair place, and if you could demonstrate the issue to that tech, then marshall would have to listen?
how long does it take before the weirdness kicks in?
-
This is the problem - I can weirdness from the start, or after a little while, or not at all :?
In fact mine has been quite stable for a week or two, but I haven't used it at home that much. I'm going to try several times tomorrow to get it to do it...
-
worth setting up a webcam or something in the event it starts? would marshall take that as evidence do you think?
EDIT: I was going to suggest taking a note of room temp, ambient temp inside the amp headshell, wind direction. position of Polaris...
-
I'll get it started somehow and then get a video clip...
-
I'm not sure they'll honour a refund/replacement if they won't recognise that there's fault?
My amp definitely went to Marshall - I spoke to the repair tech who worked on it the first time, and the second time I spoke with the customer returns lady twice.
Purpleplexi - when are you supposed to be getting yours back?
I don't know. I don't want it back unless it's right. As to replacement/refund (if it goes that far) as far as I'm concerned it's unfit for purpose under the sales of goods act. Do you think they'll want to fight me in court?
-
they'll tell you that they'll sort it in court. I've been in that position. But i think most of it is bluff. If you still have the amp you could take it to court and demonstrate why it isn't fit for purpose.
-
After playing my amp all day yesterday (off and on) I cannot get it to be faulty. At all.
I suppose that's great, but slightly annoying!
-
yeah stop yer whining, dave, what do you expect from a £1200 amp, for it to work all the time? It's certainly unfair, on an amp of that price, to expect them to cough up a whole $5 per amp (assuming what jpf said was correct, and I see no reason to suspect it's not) for a powerscaling system which is actually known to work.
:lol:
Here the link for Kevin O'Connor (of London Power) claiming that Marshall didn't want to pay for the power scaling licence:
http://www.powerscaling.com/psug/phpBB3/viewtopic.php?f=7&t=1256
-
^ thanks :)
After playing my amp all day yesterday (off and on) I cannot get it to be faulty. At all.
I suppose that's great, but slightly annoying!
it'd be great if they'd said they'd fixed it, or alternatively sent you a replacement- but since you know yours is (intermittently) dodgy, you're right, it's very annoying :lol: :( About the only thing worse than having something which is faulty all the time is something which is only occasionally faulty- at least you can get something with a fault you can prove replaced or fixed under warranty...
-
That sucks... a LOT!
-
^ thanks :)
After playing my amp all day yesterday (off and on) I cannot get it to be faulty. At all.
I suppose that's great, but slightly annoying!
it'd be great if they'd said they'd fixed it, or alternatively sent you a replacement- but since you know yours is (intermittently) dodgy, you're right, it's very annoying :lol: :( About the only thing worse than having something which is faulty all the time is something which is only occasionally faulty- at least you can get something with a fault you can prove replaced or fixed under warranty...
Yeah and you just know it's gonna play up at the big gig.....
-
That's rubbish Dave. If it were me I would be demanding a full refund and getting something else!
-
Well it still hasn't played up, just been noodling through it for an hour.
It really does look like it's fixed itself :?
-
What volume are you playing at?
-
Home levels. Power on 0, Master around 7-8.
In rehearsal it's been fine too - power around 5-6.
-
Intermittant amp glitches are the worst, especially on something that new. :(
3 strikes & out?
-
How are you finding the #34 mode - any use for it?
-
Nope. I find it cr@p to be honest. Too thin and not enough gain. I can't believe a JCM800 sounds like that????
-
Nope. I find it cr@p to be honest. Too thin and not enough gain. I can't believe a JCM800 sounds like that????
The real 1s don't, but they have to be cranked up real loud for them to get their balls
-
I get that, but with the power scaling it should sound good at low volumes?
It's the same at rehearsal too, around half power :?
-
the #34 mods add even more treble to an already trebley amp - not surprised you've found it to sound that way Dave.
-
I get that, but with the power scaling it should sound good at low volumes?
It's the same at rehearsal too, around half power :?
Do any of the low power tricks work and sound good? I've never played any amp with power scaling or anything, the closest thing I have is an attenuator.
I found that... using a lot of attenuation sounds pretty bad... that's different to using power reduction techniques (which all sound different according to design and implementation) but if you're playing through a normal rig, using low power, you're speakers are not getting driven much at all... I think that plays a part... also, when I've played with PPIMV, I find using a low PPIMV setting with a really high level setting on an average pre-PIMV creates a harsh sound which is probably the phase inverter getting smashed to bits by the preamp signal. I wouldn't be surprised if you could get that tone using power scaling.
This has led me to the conclusion that using a lot of attenuation or indeed anything to reduce volume to a low (loudish speaking level maybe) volume is never ever going to sound that good. All the power reduction tricks have their downsides from what I've read so the quieter you try to make a powerful amp, the more you have to compromise on tone.
I don't think "power scaling", and we need to remember that term applies to a specific circuit NOT found in the AFD, and similar things are the complete solution to this need for less volume while retaining tone. It just seems to be addressing 1 factor of many in what makes your tone up.
that said... it may well be the best technique anyone has come up with so far.
-
Power Scaling works. My MJW Orion had it, and sounded great, and the AFD100 in AFD mode sounds great too. Very, very good.
The PPIMV issue is that it affects the Presence circuit and at low volumes you have full presence - very trebly and harsh. The more volume you give, the lesser the effect, so it's a compromise.
the #34 mods add even more treble to an already trebley amp - not surprised you've found it to sound that way Dave.
Is that what the mods are? I didn't know that. No wonder it's not my cup of tea! I *think* there are only 2-3 changes from a standard JCM800 in the mod, so do you know what they are?
-
Power Scaling works. My MJW Orion had it, and sounded great, and the AFD100 in AFD mode sounds great too. Very, very good.
The PPIMV issue is that it affects the Presence circuit and at low volumes you have full presence - very trebly and harsh. The more volume you give, the lesser the effect, so it's a compromise.
the #34 mods add even more treble to an already trebley amp - not surprised you've found it to sound that way Dave.
Is that what the mods are? I didn't know that. No wonder it's not my cup of tea! I *think* there are only 2-3 changes from a standard JCM800 in the mod, so do you know what they are?
yes, I know the circuit changes for the #34 mods.
-
Secret then are they? ;)
I found the schematic online and it seems pretty simple - just some bypass stuff. That would explain the extra hiss and noise too...
-
Power Scaling works. My MJW Orion had it, and sounded great, and the AFD100 in AFD mode sounds great too. Very, very good.
The PPIMV issue is that it affects the Presence circuit and at low volumes you have full presence - very trebly and harsh. The more volume you give, the lesser the effect, so it's a compromise.
I think it could sound good... but is it honestly as good as the amp cranked up with your cab getting a healthy dose of voltage? How low is too low is what I'm interested in. I'm sure there is a point where the speakers just don't get that much drive to them and the response of your speakers/cab is less than ideal.
I understand that as you decrease the output level you get less and less negative feedback into (usually into) the phase inverter. However I find that when using a typical high gain master volume amp for example, once I get down to a certain volume I need to crank the presence control more (decreasing high f in the nfb further) to increase the high end again, otherwise I get a really wooly 'duvet over the cab' sound. That's with a normal master volume setup... that sounds kind of fizzy if you put too much presence on. Having the depth control at low volumes is good too. Thats all without scaling or a PPIMV. The point being that the relationship of the MV/PI/Output/NFB is a constant.
Different PPIMV's give you different results. The one i used was a potential divider on the output of the PI using a dual 1M pot. You're right, the more I turned it down the less the pres and depth controls worked... but if I then (just for the sake of an experiment) turned the pre-PIMV up, I found I got some pretty horrid distortion in addition to fizz from what you describe as the almost maxed out presence (not that all amps without NFB sound fizzy). I put the noise down to overdrive characteristics of the long tail pair phase inverter taking a full preamp signal and with NFB working against the PPIMV.
I did this in a JCM800. Standard master volume on max, and the PPIMV REALLY low. Now you could say that turning down the MV and turning up the PPIMV would solve it... and it does. It isn't power scaling however I have read that Kevin O'Conner has at some point recommended the use of a Master Volume in conjunction with particular power scaling circuits of his to act as a 'drive compensator'. When using negative feedback & scaling in the same power section, I think the PI needs to be scaled also to maintain the PI/Output/NFB relationship to a normal MV or PPIMV, otherwise you'd run into this PPIMV Presence-on-max/distortion issue again. The point here is that these power scaling ideas can vary and may not all work as well as one another.
I want to try an Egnater Rebel 20. The 'watts' controls aren't power scaling controls like the London Power circuits at all. I want to hear how well that works.
-
I think it could sound good... but is it honestly as good as the amp cranked up with your cab getting a healthy dose of voltage?
It's just different. You don't get the speakers pumping of course, but then who actually plays at that volume regularly anyway? And does everyone actaully want speakers flapping?
-
I think it could sound good... but is it honestly as good as the amp cranked up with your cab getting a healthy dose of voltage?
It's just different. You don't get the speakers pumping of course, but then who actually plays at that volume regularly anyway? And does everyone actaully want speakers flapping?
No I agree with you... but I think the sales jargon with power scaling and similar features is more often than not about obtaining 'that cranked tone and bedroom level' which to me means cranked amps pushing speakers, but that sales speak is really just a bunch of cool words that sounds good in a magazine... but isn't it always?
I think if people set out to get 'that cranked tone' at really low sound levels it's just inevitable that it won't be the same... though it could still be good. You and me know this, as does most of the forum probably. The marketing of the ideas is what I can't always stomach. Before power scaling similar phrases were probably used when discussing PPIMV's or Attenuators, and we know neither of those are ideal solutions to playing quietly in your bedroom but sounding cranked ("quietly" isn't really quantitative or a recognized reference level).
I'm not really talking about blasting the speakers out, compared to really quiet levels either. I'm only talking about the range from where your speakers start to sound good compared to not really driven. Still loud, but not '75% output from a 100watt head loud'. Resistance of the speakers varying at different frequencies and all, stands to reason there is going to be a point where the speaker response isn't that good in relation to how they are driven, and that doesn't need to mean driven to loud gig volumes...but more than likely loud for 'in your flat' volumes.
Playing really quietly into 4x12 doesn't have to sound bad... even without power scaling, PPIMVs or attenuators. It doesn't have to sound bad even when using a 100watt amp to do it either. Though it's not very convenient.
I should probably say, that all this probably varies with the style of amp. High gain master volume 100watts are probably going to produce different results in conjunction with the low output ideas compared with non-master volume amps with lots of headroom.
still... if anyone has tried the Rebel 20 and wants to let me know if the Watts pot works well, or if it sounds scratchy, I'd like to know.
-
Secret then are they? ;)
I found the schematic online and it seems pretty simple - just some bypass stuff. That would explain the extra hiss and noise too...
nah, not a secret, they're freely available online if you search for them. they're just tweaks to a JCM800, nowt flash.
-
No I agree with you... but I think the sales jargon with power scaling and similar features is more often than not about obtaining 'that cranked tone at bedroom level'...
Which is exactly what it does. Cranked AMP tone at bedroom level.
-
hahaha. come on, man. A cranked amp through no speakers is NO tone.
If you define "cranked amp tone" as playing the head cranked with a complete disregard to the speakers or cab you use then fair enough, technically you're right. Nobody says "cranked amp and speaker tone".
For me, the tone that phrase refers too is stuff like Hendrix & Townshend. To me, THAT is cranked amp tone, and when you hear it, it is inclusive of the speaker tone. Without that part, you can crank the amp up all you like, but at the LOWEST volumes, its still going to be nothing like the above, no matter what method of attenuation you use.
If I'm wrong for thinking that because I'm not interpreting that phrase literally, whatever.
-
I'm speaking about what the Power Scaling system is designed to do - have the amp cranked at low volumes. Which is what is does superbly.
An amp with PS can't replicate speakers cranked can it! :lol:
Everything is a compromise, for me PS is the best compromise there is :)
-
:D
I don't think im disagreeing.
No doubts power scaling does what it does well when installed well, and you can get good tone at low volumes with or without PPIMV's, Power Scaling or Attenuators but you do need to compromise. I think the "best method" varies from person to person and amp to amp.
I never imagined it could replicate speakers either.:D I just think for me, cranked amp tone is something different to overdriven power stage tone and PS etc are not really methods for replicating a loud gigging kind of sound at tiny practice amp levels, It's another tool in the box and handy for getting to a similar place, but when I read some stuff it just seems like people think it's going to make their amps sound like they are pumping out the watts at knebworth, when in fact their squeaking out the power in the bedroom, and we both agree that isn't going to happen.
-
Nope :)
Nothing can replicate pumping out the watts at Knebworth!
-
Nope :)
Nothing can replicate pumping out the watts at Knebworth!
Haha... when you do that I expect a guestlist spot.
-
Secret then are they? ;)
I found the schematic online and it seems pretty simple - just some bypass stuff. That would explain the extra hiss and noise too...
nah, not a secret, they're freely available online if you search for them. they're just tweaks to a JCM800, nowt flash.
Are they the kind of mods that can be errr, un-modded in the traditional way - like changing resistor values or whatever? Or would I need a new specialised chip made in a top secret lab in NASA HQ?
I'm jus thinkin - a little less difference betweeen the 2 modes might help. It's not supposed to be a JCM anyway is it? I though #34 was a plexi with an extra tube in the gain stage.
-
#34 is a bog stock JCM800 (Plexi + a gain stage) with three brightness mods, as far as I can tell.
AFD has one extra stage over a Plexi (i.e. same as #34 and a JCM800) but a different EQ structure.
I think that's the difference? The EQ changes around the gain stages of the modes is why the AFD100 needs 5 preamp valves instead of the usual 3. They probably share the Phase Inverter?
-
#34 is a bog stock JCM800 (Plexi + a gain stage) with three brightness mods, as far as I can tell.
AFD has one extra stage over a Plexi (i.e. same as #34 and a JCM800) but a different EQ structure.
I think that's the difference? The EQ changes around the gain stages of the modes is why the AFD100 needs 5 preamp valves instead of the usual 3. They probably share the Phase Inverter?
the #34 spec is just a JCM800 2203/2204 with a few circuit mods.
the #36 and #39 specs are the same JCM800, but with an additional gain stage added.
-
Not directly related to the problems with Dave's own amp, but has anyone seen the review of the AFD100 in the new issue of Guitar & Bass magazine?
We've often commented that magazines never seem to give bad reviews, but here's an exception! The reviewer wasn't keen at all - just 13/20 for sound. Of course it's all a matter of personal taste, but he thought the amp sounded very "harsh and spiky".
-
Yep, I saw that. Did you also notice that they tested the amp with the power scaling "off"? That's why it sounded thin :roll:
I also wondered what cab they played it through...
-
I would have hoped the reviewer would have had the amp loud then?
Also, the power scaling is a major feature, does the article look over it completely?
-
It mentions it towards the end of the article, but I was really surprised with the review to be honest...
-
maybe the power scaling wasn't working properly - ouch! :lol:
sorry, had to be said.
-
Yep, I was surprised with the 'less than glowing' review GnB gave the AFD100 too.
I've been getting that magazine pretty much constantly for the last 12 years or so and don't remember reading an amp review quite as scathing as that 1 came across as being :?
-
is this review online anywhere?
-
is this review online anywhere?
They tend to put them online themselves (the mag) a month or 2 after the issue has been on sale.
-
Yep, I was surprised with the 'less than glowing' review GnB gave the AFD100 too.
I've been getting that magazine pretty much constantly for the last 12 years or so and don't remember reading an amp review quite as scathing as that 1 came across as being :?
I heard from some who works as a music journalist that it had got a bit of a clattering in the review (I haven't seen the review myself).
Perhaps the reviewers are getting bored with giving everything a glowing review and there will be a bit of a backlash.
Hope not as one of our amps is going for review soon.......
-
So what's the score now Dave? Any more issues?
-
It's wobbled once in 3 weeks, and only once. That was at the minimum power setting late one night. Otherwise it's been fine :?
-
Did you guys see that other thread on another forum where the amp designer came in and in the end everybody agreed that the problem was normal behaviour at lower power reduction settings, caused by voltage flutuations, and solved by the use of a voltage regulator on those places?
-
Yup.
-
Nope - no schematic Fernando.
I've subscribed to the Marshall forum so there's now at least three of us there with an issue. Not good for Marshall is it?
Indeed not good.
From what gwEm says, sounds like it is a well-known problem with this sort technology, which would suggest that Marshall don't understand it fully.
I've logged into the "super secret" Marshall schematic service facility and there's no schematic there. I expect there won't be until it goes out of warranty.
Regarding the "Power Scaling", what I have gleaned is that the screen grid voltage and bias voltages are varied, rather than the plate, screen and bias voltages, and that this is controlled by some digital which has a number of stepped power levels, and this seems to be where the problem is.
As ever, using "cutting edge" approaches often reveals unexpected problems.
Hello.
The thing is the following:
1)First of all AFD and YJM use the same EPA (electronic power attenuation) circuit: I have made comparison by looking PCB and also by reading in the manual the explanations on autobias, on the use of the POWER pot in AFD (called LEVEL in YJM) I am quite sure is exactly the same circuit.
2)It is all based on a patent of the 80's that expired few years ago (therefpre Marshall use it without infringment). This patent was based on moving bias (control grid) and screen grid voltages in order to keep their ratio constant. If you do that the characteristic of the tube keeps the same shape (tone remains the same) but the clipping point moves to lower levels.
3)According to Marshall designer Santiago Alvarez they made some difference respect to the patent. By examining the AFD circuit (missing the digital part schematic) there are 4 regulators which provide a negative voltage for the bias and one High Voltage regulator, which provides screen voltage.The bias ones are following a voltage called VBC1 while the screen voltage regulator follow a voltage called VS. I don't have the schematic of the digital part of this amp (nobody has posted it yet) but I am quite sure that VBC1-4 and VS come from a digital control (like a microprocessor that digitally drives the voltages trough DACs) according to POWER potentiometer position. Moreover the LEVEL/POWER control acts at our ears like a "step" volume and not linear. This may confirm that there is a digital circuit controlling bias and screen voltage according to certain equations/laws or a simple LUT (look up table). Instead the original patent of the 80s was keeping screen voltage/bias ratio approximately constant with a continuous range (full analog!).
4)Finally remember that current in Pentodes (power tubes) do not depend on plate voltage but strongly on screen voltage (and of course also on control grid).
5)The POWER potentiometer is double (shared axes): one acts probably on the (missing schematic) digital circuit that, on his turn, regulates VS and VBC1-4; the other one acts on the power stage feedback in a way that it tries to compensate (as Alvarez stated) the power stage when changing POWER level. This should be done because when you change bias/screen voltages the stability characteristic of the circuit change, therefore you have to adjust the feedback to try to keep them constant.
4)Conclusions: this is the best post phase inverter volume reduction because it does not use any kind of potentiometer/circuits in the analog path; it reduces the power maintainig the characteristics of the power tube constant. It is the ultimate mod for any NON master volume amp. What is difficult to achieve is to implement the bias/screen regulating law using an analog circuit instead of microprocessor (if it uses micro according to my supposing...again, missing the digital part schematic that would reveal if my supposing is true).
The EPA circuit works also on EL34...the manual of YJM and AFD tells that trough a bias table!
Hope I gave an help with this.
Regards
-
First of all, way to dig up a thread from 2011.
I'm sure the AFD and YJM have the same or if not the same a very similar circuit to do the power attenuation, whatever they call it.
Attenuating the screen grid variable voltage is more easily done than varying the plate since the power needed to be dissipated is lower. I don't think it is difficult to get a variable screen voltage with bias tracking without the aid of a microprocessor and without having high voltages on any pots, it may be a bit less accurate in terms of how it tracks bias but this idea isn't new at all. I think this circuit also works using 21 steps and appears to have had some dither issues. Essentially this is using a dual pot controlling a digital circuit in turn controlling variable bias and variable screens and in an analog fashion varying the negative feedback, which is the long and short of what JPF said.
I'd say it's probably one of the better concepts for a circuit of it's kind, but how it has been implemented may have left a bit to be desired. Also, if you're Non Master volume head doesn't use negative feedback, you wouldn't have to 'mod' it to use a circuit that varies the negative feedback along with output power, correct? So you may not want to use this circuit in 'ANY' non master volume head.
I'm also a fan of keeping it simple and reliable, especially when it comes to the bias circuit. Using common parts and keeping things easily repairable is always a good touch in my opinion. If I broke a microprocessor in a guitar amp and I was on tour, what would I do? meh. That's just my personal thoughts on that stuff.