Bare Knuckle Pickups Forum
Forum Ringside => Guitars, Amps and Effects => Topic started by: Mr Ed on November 07, 2007, 10:18:06 AM
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Ok, I've been having major problems with getting my amp sorted lately. I took it to a local guy who turned out to be a major tool - it took him 6-8 weeks to $%&#ing retube and bias my amp. Firstly, he'd just gotten divorced and so was moving, then he was on holiday, then the postal strike screwed everything up and blah blah blah.
Anyway, I have it back now but it got me thinking... it would be SO much easier if I had an amp that didn't need to be biased so I could just buy tubes myself and pop them in and bam, away I go.
Can anyone recommend any amps that are very much along the same sound-lines as a 900?! I adore the high gain sounds and it has very useable but not sparkly, pristine cleans.
Most of the time, I'm using my Fernandes Ravelle through it but I'm leaning more at the moment towards my Lace Sensored Fender MIJ 1957 Strat... if that's of any use whatsoever.
I need a proper dual channel amp, I'm not arsed about having to share an EQ - I've managed fine with the 900 so far. As for price, I'm not gonna lie and say I have megabucks to spend - I don't - I'd be looking at about £500 absolute top end maximum price. Preferably closer to £400. If not possible then I'll just carry on for a year or so until I can afford a bit more, it's no problem as I simply love the sound.
Any suggestions would be greatfully received, chaps and chapesses.
:D
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Wouldnt it be easier to learn how to bias yourself? :)
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Exactly what I was thinking! Having seen it done, it seems simple enough. I think your JCM900 has an adjustable bias pot making it very, very straightforward.
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in anycase, i thought only Class A amps didn't need biasing.
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There are many amps that have a fixed bias like most of the Mesa amps
You have to be careful which tubes to buy
An alternative is to have the amp set up with one of the graded sets of tubes like you get from Groove tubes and then you can just buy replacements with a similar grading on them and pop them in with no ill effects at all
third option is to read up and get a bias probe and learn to do that job yourself as the other guys have suggested - although I should add one caveat - Tube amps contain high voltages that can kill.
Some people simply are not well suited to that kind of techie work even though they may be great musicians and should just allow a qualified/experienced tech to do the work
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That's my perspective, I don't feel confident messing around with it and so don't wanna risk my health (or my amp for that matter).
An alternative is to have the amp set up with one of the graded sets of tubes like you get from Groove tubes and then you can just buy replacements with a similar grading on them and pop them in with no ill effects at all.
Sorry, that's French to me. :lol: The technical side of amps is my weak point.
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There are many amps that have a fixed bias like most of the Mesa amps
You have to be careful which tubes to buy
An alternative is to have the amp set up with one of the graded sets of tubes like you get from Groove tubes and then you can just buy replacements with a similar grading on them and pop them in with no ill effects at all
thanks for this clarification feline
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I got it back a week ago and tonight was the first practise we had together. It had a 15-20 minute warmup and all was sounding good... real good... better than before in fact, a little warmer, a little louder and we were happy.
We started our first song - "When I Sleep".
Halfway through, $%&#ing kaputsville again. I'm the Mayor of this town once more.
Popped the back off, the first pre-amp tube (the same as last time) has cr@pped out.
To say I'm not happy would be a $%&#ing understatement. I've not bought him home with me, I'm in too foul a mood to do anything about it and I've got a pretty full on week that I can't afford the time to $%&# with this. Here's the plan:
1. Next week, take it to the shop and tell them to get it back to that useless ####!! and fix it... for free... within a week.
2. Get it back and $%&#ing sell it. :(
As much as I love it, and I do LOVE the sound, the well-known Marshall unreliability factor is rearing it's ugly head and I can't stand it. I don't know what to do. I dunno where to turn...
Two true channels with separate EQ.
FX loop.
Master volume preferable.
Reasonably high gain.
Laney TT? Rivera Knucklehead? I just don't know.
I'm so amp-depressed right now, back to using Pete's turdy AVT> :(
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Bad luck there. Is it Dual Reverb then?
I have no serious problems with my dual master volume.
The shop should replace it anyway, as tubes are usually covered by a 3 month warranty?
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Yeah, it's the 4100 100w dual reverb.
They better had sodding fix it under the original price - as far as I'm concerned the work hasn't been chuffing finished.
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If it's a new 'applience', I think you need to give them three opportunties to try and fix it then you're within your rights to demand a replacement.
If it were me I'd be wanting a replacement after the first f*cked up repair attempt.
I'm trying to think why the first preamp valve would keep burning out - very odd. I've never seen that happen EVER.
I'm very not familiar with that amp, but I seem to recall Marshall using a DC heater circuit on V1 ONLY with the JCM900s. My gut feeling is that there is something up with that section.
Plug the V1 valve in the V2 slot - if it lights up, chances are that the valve is fine and my hunch is correct.
:twisted:
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Just found a dual reverb schematic, no DC heater circuit, just straight-forward AC heaters like all old Marshalls since day one.
Maybe it IS just a dodgy preamp valve, or could be a cracked/intermittent joint on the valve base - assuming they're pcb-mounted valve bases.
:twisted:
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Two true channels with separate EQ.
FX loop.
Master volume preferable.
Reasonably high gain.
Laney TT? Rivera Knucklehead? I just don't know.
If you're going down the Laney route, I guess the VH100R or similar would be a good idea, and I think it does everything you want it to. Not sure if it'll have quite the same tone as Laneys seem to be a bit more lower-mid voiced, but I've had my GH almost a year now and have had no reliability problems, in fact I still have the stock valves in and it sounds great. Heres a pretty nice clip someone on HC did of their VH100R into a Framus 2x12 (V30s):
http://lucaonida.googlepages.com/Rock185.mp3
And thats with stock Ibanez pickups :o
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If you're going down the Laney route, I guess the VH100R or similar would be a good idea, and I think it does everything you want it to. Not sure if it'll have quite the same tone as Laneys seem to be a bit more lower-mid voiced, but I've had my GH almost a year now and have had no reliability problems, in fact I still have the stock valves in and it sounds great. Heres a pretty nice clip someone on HC did of their VH100R into a Framus 2x12 (V30s):
http://lucaonida.googlepages.com/Rock185.mp3
And thats with stock Ibanez pickups :o
Nice one mate, I dunno which route I'd go down IF I decide to get rid... watching the Rivera Fandango videos has made me too damp to sleep! :D
FOOK ME! That clip sounds grand!! :o
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Just found a dual reverb schematic, no DC heater circuit, just straight-forward AC heaters like all old Marshalls since day one.
Maybe it IS just a dodgy preamp valve, or could be a cracked/intermittent joint on the valve base - assuming they're pcb-mounted valve bases.
:twisted:
I'm pretty sure they're chassic mount sockets- they are on my 50w, haven't opened my 4100 up to have a look under the bonnet yet though.
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Sounds like a dodgy valve base to me. Easy and cheap fix that the shop should do for.
Failing that, take it to Gee Electronics. They're in your neck of the woods and know valve amps.
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Cheers amigos, I'll have a look for Gee Electronics.
Do you reckon if it is a dodgy "valve base" as you chaps seem to think, the valve that's in there at the moment will be buggered, ie, would that just not be powering it at all or could it have blown it too? Sorry, I'm useless with ampage.
I've been eyeing more amps though... even once I get this fixed, the biasing thing is always gonna be a problem for me.
I've gone against myself and been looking at Boogies - F50's, DC-5's and DC-10's. :oops:
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Yep, if the valve base has shorted out it'll cause bits of the valve to be connected that shouldn't be connected.
What do you mean when you say V1 "cr@pped out"? If it's black inside and rattles then it's plainly busted and you wouldn't be asking the question!
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It's not getting any power - I popped the back off and had a peek inside, turned all the lights off as it was running. Working on the principle of left ro right:
-- Pre-Amp ------------------ Power Amp
V1 | V2 | V3 -------------- V1 | V2| V3 | V4
The first pre-amp tube had no light so I figured was getting no power to it. With my lack of amp experience, I didn't know whether to point the finger of blame as tube or amp but you guys seem to be fingering the amp. Har har, fingering.
Hell, while I'm going I may as well ask the guy if there's any way he can permanently fix the bias on it.
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Hmmmmm. Like I say, I think I'm gonna speak to this amp dude next week and see if there's any way he can permanently bias the amp - in the Mesa Boogie fashion - without it effecting the tone or anything. If so, I'm sorted.
If not, I got some good news today... I've been given about a thousand pound from my Grandma as a sort of... nest egg, she's still alive like, and I'm tapping into £700 of it in order to pay my car insurance and then paying it back into this account over the next 12 months. Basically, I'm loaning off my own emergency fund.
So. That leaves me with about £300... if I was to sell the 900 (if the guy can't bias-fix it) then I'd have about £600 (post sale) to spend on a new amp... plus the possibility of a little extra if i get this promotion in work.
Come the new year... if things do (and don't) go my way, I could drop a grand on a beast.
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Hmmmmm. Like I say, I think I'm gonna speak to this amp dude next week and see if there's any way he can permanently bias the amp - in the Mesa Boogie fashion - without it effecting the tone or anything. If so, I'm sorted.
If not, I got some good news today... I've been given about a thousand pound from my Grandma as a sort of... nest egg, she's still alive like, and I'm tapping into £700 of it in order to pay my car insurance and then paying it back into this account over the next 12 months. Basically, I'm loaning off my own emergency fund.
So. That leaves me with about £300... if I was to sell the 900 (if the guy can't bias-fix it) then I'd have about £600 (post sale) to spend on a new amp... plus the possibility of a little extra if i get this promotion in work.
Come the new year... if things do (and don't) go my way, I could drop a grand on a beast.
You should have Dakine's Knucklehead - such good amps!
You dont need a fixed bias like the Boogie but rather have the amp biased for a particular geade of tube - like Groove Tubes do and then you can swap outthe valves for similar graded ones with no changes required (in theory)
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You should have Dakine's Knucklehead - such good amps!
You dont need a fixed bias like the Boogie but rather have the amp biased for a particular geade of tube - like Groove Tubes do and then you can swap outthe valves for similar graded ones with no changes required (in theory)
I wish! Knucklehead's make me damp.
So... if I was to have it biased for, say, a full set of 3+4 JJ tubes and I ONLY stuck with them, I'd never need it rebiasing?
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Preamp tubes don't need biasing.
and I don't think JJ do that. It would have to be a graded tube, like Groove Tubes do. If your amp is biased to a particular grade, in theory, you could buy that same grade with no need to have it rebiased....in theory (as feline said)
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I think I see what you mean, each brand of tube is graded differently and you only need to bias when moving between different grades.
Right.
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I think its only Groove that grade them
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Have a look here for an explanation of the power tube grading
As said before Preamp tubes are not biased but are often graded for tonal characteristics etc
http://www.guitarxs.com/groovetubes/default.asp
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Oohhh I getcha mate.
After some calming down, I think the logical thing to do is get the valveplate looked at and fixed and spend a few hundred quid on a backup amp.
Now taking suggestions on that, hehe.
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Backup?
Laney GH50L. No question. £250.
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If you go to Hotrox or Watford Valves and buy a set of output valves, they will come with a number on the box, in mA.
If you bias for these valves, you can then order from HR or WV (others may do this too) a set of valves with the same number on the box, and fit them without biasing, as has been said.
There's nio reason why that amp shouldn't be reliable, given a good tech. :wink:
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Backup?
Laney GH50L. No question. £250.
I have considered that, a lot... I would prefer a dual channel amp but if it's only gonna be backup, hmmmmm. I'm watching one on ebay, could really do with testing one out at some point to make sure it's gainy enough for a gain slut like me.
Plus, Gilberto uses 'em so that's a bloody good start, heh.
If you go to Hotrox or Watford Valves and buy a set of output valves, they will come with a number on the box, in mA.
If you bias for these valves, you can then order from HR or WV (others may do this too) a set of valves with the same number on the box, and fit them without biasing, as has been said.
There's nio reason why that amp shouldn't be reliable, given a good tech. :wink:
AAAHHHH! Right, ok, that's the level of English explanation I need! NUMBERS ON BOXES!!
I'll be visiting a tech next week, christ knows how I'm gonna pay for it though but yeah...
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Do you have a POD? Or a GT8 or similar multi effect unit with its own FX loop? You can make the GH50L into a 2ch amp by using the loops to use the multi's preamp for cleans and the GH50L's own sound for gain. I've never done this because there was no need with my VH100R but it seems like a very good idea.
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Nah, I'm a stompboxes guy myself - I figure I can use my volume pedal to create a 2 channel sort of. It's only gonna be backup.
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Sounds like a dodgy valve base to me. Easy and cheap fix that the shop should do for.
Failing that, take it to Gee Electronics. They're in your neck of the woods and know valve amps.
Mate, you were SO right.
I dropped my amp in monday, they've rung me back tonight and told me one of the resistors (or something) that regulates the power delivery to the tube that keeps blowing is knackered and the amp needs to be stripped down, serviced, replace the part and the tube. Might have it back tomorrow, gonna be 65-80 quid.
Thanks so much for the recommendation, I have a gig on the 28th and I NEED my amp 100% by then, looking very realistic. 8)
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I've biased amps using many different methods, shunt, resistor and a bias probe.. I must admit I've had a shock a few times and they're most deffinatly not pleasant, im probably very lucky to be alive.
I've had 3 major shocks from valve amps and I've been blown across the room on one occasion, stuck to the amp unable to let go at one point recieving a whooping 500v.. luckily I was only holding it with one hand and I had some pretty nasty nerve damage, my hand was a shaking wreck for weeks still feels odd even now and this is a year later.
I would advise you know what your doing before modding or biasing an amp, I know what im doing and even i've screwed up a few times. Is it really worth the hassle?
Get a Pro to do it.
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I've biased amps using many different methods, shunt, resistor and a bias probe.. I must admit I've had a shock a few times and they're most deffinatly not pleasant, im probably very lucky to be alive.
I've had 3 major shocks from valve amps and I've been blown across the room on one occasion, stuck to the amp unable to let go at one point recieving a whooping 500v.. luckily I was only holding it with one hand and I had some pretty nasty nerve damage, my hand was a shaking wreck for weeks still feels odd even now and this is a year later.
I would advise you know what your doing before modding or biasing an amp, I know what im doing and even i've screwed up a few times. Is it really worth the hassle?
Get a Pro to do it.
All that shiz is the exact reason why I won't touch anything inside my amp. :D
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James, how did you get shocked and were you taking suitable precautions? When I bias I work with the principle of keeping one hand out of the amp at all times and also use insulated screwdrivers.
How do you get blown across the room by the way? Do your muscles just spasm and make you jump off or did it cause an explosion? Just out of interest.