Bare Knuckle Pickups Forum

Forum Ringside => Guitars, Amps and Effects => Topic started by: indysmith on September 07, 2005, 09:27:19 PM

Title: New Jcm800 4104
Post by: indysmith on September 07, 2005, 09:27:19 PM
Hi everybody, I just got a new JCM800 2x12 50W combo, and I LOVE the sound it spits out (my first valve amp). However, the overall tone sounds amazingly trebly compared to what I'm used to, and also it seems to have a lot less gain.  I'm just checking with you guys that the amp should sound like this? I can get great sounds out of it, if i turn down the treble, and the presence, boosting the bass and the volume, but it just seemed a bit odd, being that treble-focused. i suspect the low gain could be caused by the fact that it still has the original valves in it (which have probably had it after 26 years, although it hasn't been used a lot), and i should probably replace them. I also suspect that the super-trebly sound could perhaps be due to these old valves, OR the fact that i live with my family, and i haven't yet had the chance to crank the amp up to high volume levels (not yet over 2.5 on master volume).
I'd be very appreciative of any help I may recieve.  Thanks all.
Title: New Jcm800 4104
Post by: crispsandwich on September 07, 2005, 10:04:02 PM
I've never owned a valve amp but I'd say if they're the original valves then you should replace them ASAP. Make sure they're good quality ones like JJs and they'll probably do wonders for your tone. The thin sound could be present because you haven't had the chance to turn the amp up to full, which would drive the valves to produce the dynamics and tone that only hard driven valves can produce. If you're mostly a bedroom player it would probably be wise to buy a power attenuator, which will allow you to drive the power amp at sensible volumes. I played a Marshall JCM2000 Triple Super Lead (I think) at low volumes in a music shop once and it sounded horrendous. I think Marshalls have to be driven to get that signature tone.

-Danny :D
Title: New Jcm800 4104
Post by: chrisola on September 07, 2005, 10:34:14 PM
lots of JCM 800 owners on here to help out once they read this...

when i had my 1x12 combo, it had original valves etc and i could get a killer Slayer esque tone...

The secret is, you need to boost the amp with a pedal.

Get a Boss sd-1 (or even a Keeley SD-1!), set the level high, the gain on the pedal lowish, kick it on and BOOM the JCM comes alive and sounds freaking amazing!!!

Its not a high gain amp, its more of a classic sounding one that needs a boost in the ass to REALLy shine :)
Title: New Jcm800 4104
Post by: indysmith on September 08, 2005, 07:54:38 AM
Wow, thanks guys for the quick, useful replies, those were both things I considered to be the problem. I'd better get saving for a Keeley SD-1 and a THD HotPlate. Always things to buy isn't there?  :P Right after i just spent every penny on a new amp, its gonna cost me like another 300-400 for an overdrive, a new set of valves and a powerattenuator. hehe.
Title: New Jcm800 4104
Post by: chrisola on September 08, 2005, 09:17:48 AM
is that mesa boodie v-twin an overdrive pedal?

use that, turn he pedals output up and the drive on it down... might do the trick!
Title: New Jcm800 4104
Post by: HJM on September 08, 2005, 10:18:22 AM
The JCMs smooth out at volume, they are a bit bright at low level.
Keep the presence down at home - also try an extension cab and different speakers, they sound better pushing more drivers and different models tailor the sound. A Hotplate does help a lot with the high end.

Get the OD first, the Zakk Wylde MXR overdrive is the best value, next the Keeley SD1 or even TS9.
Title: New Jcm800 4104
Post by: donbarzini on September 08, 2005, 02:57:22 PM
I was looking for that same combo myself but I needed sparkly cleans also. I was recommended to try the Traynor YCV50.

http://www.yorkville.com/products.asp?cat=18&id=318&type=32

So far, I think it is great! I revalved it with JJ's and it totally screams with my Keeley SD-1. I've heard from others who owned JCM800's that the voicing on this amp is very similar so I guess I am getting the best of both worlds, Marshall gain and Fender cleans.

Looking forward to receiving my Genz Benz G-Flex 2x12, it should roar with this cabinet.
Title: New Jcm800 4104
Post by: indysmith on September 08, 2005, 06:11:20 PM
No chrisola, the V-Twin's a floor Preamp. I think i'll go for the Keeley SD-1; the soundbites on the site are delicious. whilst on the subject of cleans; i was very pleasantly suprised by the cleaner side of the JCM800 (on the low level input), i found it really sparkles nicely, and is nowhere near as muddy and unclarified as the mesa's. Also chords sound great with it, clipping quite softly into overdrive, which is a luxury i'm not used to. Obviously it is a marshall flavoured clean- and not pristine sparkly like a fender, but i really prefer the sound of this clean to the clean of the twin, which seems kind of boring to me. (sorry to anyone who finds what i have just said to be pure blasphemy) I really think that JCM800's are underrated for their cleaner side. i think it's beautiful, however- this may just be my opinion.
I love my current set-up. It has major versatility. I can get pretty much any rock guitar sound out of the Ibanez (obviously not brilliant matches, but all pcikups positions sound GOOD. and the amp is brilliant with classic valve marshall sounds coming at me, and then if i feel like it, with the tap of a foot (and a few other tweaks) i can jump across from bletchly to petaluma, and i have a more modern and americanly voiced sound with the V-Twin. I'm very happy. Thanks for your help everyone. Does anyone reckon that i could get some more low-end out of closing the back of the JCM800? and if so, has anyone got any ideas of how i could do this obviously without harming my pretty much  mint condition beauty?
Rock and Roll all!
Title: New Jcm800 4104
Post by: indysmith on September 08, 2005, 06:19:06 PM
also, while i'm thinking about it, since a lot of yu have JCM800's (i've been looking through these forums for a while now, although i never really got the urge to post until lately), do any of you have
a) some *holy grail* settings on a JCM800, that i may not have found yet? and
b) any reccomendations of what bareknuckles to put in a mahogany body Ibanez S-series for a tone that can go from high gain Wylde sounds to more vintage Rhoads sounds, to lower gain classic crunchy overdriven sounds, all with the use of a volume knob. (does that sound picky to you? :roll: ) muchlove all
Title: New Jcm800 4104
Post by: Ratrod on September 08, 2005, 07:15:06 PM
That Mesa V-twin can be used as a booster, right? Experiment with it, try some of the different outputs. I think you could even recreate the cascading preamp thing of the Mesa Mark IV.
Title: New Jcm800 4104
Post by: FELINEGUITARS on September 09, 2005, 01:11:24 AM
Quote from: indysmith
also, while i'm thinking about it, since a lot of yu have JCM800's (i've been looking through these forums for a while now, although i never really got the urge to post until lately), do any of you have
a) some *holy grail* settings on a JCM800, that i may not have found yet? and
b) any reccomendations of what bareknuckles to put in a mahogany body Ibanez S-series for a tone that can go from high gain Wylde sounds to more vintage Rhoads sounds, to lower gain classic crunchy overdriven sounds, all with the use of a volume knob. (does that sound picky to you? :roll: ) muchlove all


I'd say Miracle man for that.
Any of the high gain models will get you there in one way or another.
A crawler set will sound massive , the nailbomb will have more grit and aggression , but for my money I'd go miracle Man bridge and Mule neck.

I think the cold sweat set could sound great but you will probably prefer the Mule in the neck position for a mix of Zakk ands Randy neck tones.

We made Tim a mahogany Explorer and he put Mules in that and it just sang like a bird - it was awesome.
Title: New Jcm800 4104
Post by: indysmith on September 09, 2005, 07:34:17 AM
all right, i'm set on the mule in the neck, but kind of torn about the bridge. Whats this cold sweat set i've heard so much about?? its not on the products page and i can't seem to find any soundclips of it. i feel i've missed something! fill me in!  :P
Title: New Jcm800 4104
Post by: HJM on September 09, 2005, 08:08:28 AM
Don't close the back of he amp - it'll get too hot! Try an extenion cab, a Boogie Thiele cab would add lots of bottom end in a small package, or check out the Genz Benz  G-Flex

Settings - on the single channel JCMs which I use I have 2 settings, gain at 7, Bass full, mid7 treble6, presence 2-3, that's for lower gain. Second Gain full, Bass Full, mid about 6, treble 7 , Presence 2-3 and boost with a pedal.

Now, there's a treble cap on the gain control in JCM800s, I think your amp will be the same. What it does is keep some reble in the tone at all gain levels, but I find it a bit too much, if you remove this cap it looses a bi of top and warms it up a bit when you're using less gain - but you'll stll get the same tone at full volume.
Title: New Jcm800 4104
Post by: indysmith on September 10, 2005, 01:37:30 PM
i got out a mg50dfx (MEH, i know) and plugged the JCM800 into that aswell as it's built-in celestions. didn't like the sound though :? , since the speaker in the MG is absolutely rubbish!!! was fun to have a go anyways i guess. good spread of sound (i had them back to back in an empty room - nice natural reverb) :P
Title: New Jcm800 4104
Post by: indysmith on September 10, 2005, 01:52:40 PM
where abouts is this treble cap you speak of? and what do i need to do to remove it?
Title: New Jcm800 4104
Post by: HJM on September 10, 2005, 05:42:13 PM
If it was a single channel amp I'd take you right to it, but I'll have to look in teh good old tube amp book later!
Title: New Jcm800 4104
Post by: indysmith on September 10, 2005, 10:21:35 PM
dude the 4104 is a single-channel! its the 50w 2x12 combo version of the 2203 silly.
Title: New Jcm800 4104
Post by: Skybone on September 11, 2005, 11:41:10 AM
Hi indysmith,
I've recently got a 4104 myself, and I have to agree that it's a damn fine amp! As far as I know, it IS a two channel amp, except you don't have the facility to change channels whilst playing, you have two inputs instead, high & low.
Congrats on your excellent choice of tone shaping tool! ;)
Title: New Jcm800 4104
Post by: indysmith on September 11, 2005, 12:09:33 PM
hehe, yeah, its definately kicking some ass atm, now that i've had the chance to play with it a little, I've found that i can use the blues channel on my Mesa as a great gain boost for it, and also, with it set up right, now much of an e.q. difference - it still sounds like a JCM800!  :D  i always thought that the 4104 was a single channel, and the inputs were just applying different levels of gain on the same preamp. (like a split channel kind of idea?) I'm probably wrong, and everyone else is probably right, but i thought the 4211 (or something like that) was the 2 channel version? no? doesn't really matter either way - it sounds great, and i can coax almost any sound i desire!
Title: New Jcm800 4104
Post by: HJM on September 11, 2005, 02:01:47 PM
Oops, yeah dumbass me :lol:  That'll teach me to check my facts!

You now need to tell me if it's got the pots mounted on the circuit board, if it does it's more of a pain in the ass. If not, there's a small disc cap accross the preamp control, cut it out and that'd the mod. I've known some gurus charge a fortune for this mod!!