# Thoughts on the JCM 900 amps?



## Greg Ellis (Oct 1, 2007)

I see JCM 900's selling fairly regularly (on the used market) for a LOT less than the JCM 800 equivalents.

Any thoughts on why?

On the surface, with dual footswitchable channels and an effects loop, JCM 900 looks like a major upgrade.

I know that part of it is the "mystique" of the JCM 800 - it's a classic, and that drives up the price at least somewhat.

But what explains the bargain prices on the 900 line? Thoughts?


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## Robert1950 (Jan 21, 2006)

I think someone on this forum uses/or used the tagline "After the JCM800, it was all downhill." I believe they switched to PCB board thingys in the production of the JCM900. I think Wild Bill would be able to write a thesis on why.


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## ajcoholic (Feb 5, 2006)

I bought and used a JCM900 1x12 combo (with the 5225 tubes) a number of years ago.

Basically, it is a very hot amp - lots of gain. But not too much else IMO. The cleans are lacking - very lack lustre clean tone. No sparkle.

The amp also didnt seem to cut through very wellno matter how I worked the tone controls and even at very loud volumes (mine was a 50W version).

There are much better amps out there in the tone dept, thats for sure.

But it was fun when I didnt know any better 

AJC


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## sproul07 (Jun 23, 2007)

The 900's, as it was said earlier, lack in cleans and tonal depth. I find an effects loop and reverb on a Marshall to be unnecessary, the best sounding ones don't have the junk on them. 800's, Plexi's, JMP's


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## Scottone (Feb 10, 2006)

They're mediocre sounding amps IMO. I bought one of the 2x12 combos the first year they came out and was never happy with my sound. 

You're definitely better off with the JCM800 or 2-input JMP head (my personal favorite Marshall). Stick with the 2203 or 2204 models.


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## Tarl (Feb 4, 2006)

I owned a JCM900 50 watt head for about 5 years. It was made in 92 I belive, and switchable to 25 watts. It is true that the cleans are less than stellar but can be very passable (chorus can be your friend). The distortion side of things was very well done. To me it sounded sort of Marshall meets Mesa.....leaning more to the Marshall side. Well built and reliable as far as I was concerned.....really wish i had kept it. Perhaps the heads and combo owners had slightly different experiances.


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## SinCron (Mar 2, 2006)

I tried the 900 when I was in the Halifax Music Stop for the first time and I was thinking "Now I get to try that awesome legendary Marshall" thinking at the time that Marshall amps were "the shit" but when I tried it, I took "the" out of it. I thought it sounded like crap. The gain was horrible. Not only did it seem to be lacking, it seemed to have a complete shit tone like it had a tin sound to it. I don't know if anyone knows what I mean by the tin thing but it just has a sorta..... tin resonance to it. I don't know how to put it. But as time moved on and I tried other Marshalls, I discovered something. I don't like Marshall. Lol. The the distortion I ever got was with amp modelers but when I get my Bugera, all that will change.


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## kruts (Apr 30, 2006)

JCM 900s use diode clipping in the preamp for distortion. JCM 800s do not use diode clipping and as a result sound warmer because the clipping is 12AX7 tube based. In addition 900s have preamp tubes mounted directly on the PCB (well so do bogner XTCs, so who cares right?)


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## gproud (Mar 2, 2006)

kruts said:


> JCM 900s use diode clipping in the preamp for distortion. JCM 800s do not use diode clipping and as a result sound warmer because the clipping is 12AX7 tube based. In addition 900s have preamp tubes mounted directly on the PCB (well so do bogner XTCs, so who cares right?)


Only the Dual Reverbs have diode clipping. The MK III and SL-X don't. Pure tube tone, and great sounding amps IMO. I agree the DR's do not sound great on either channel, but the SL-X and MK III are great amps.


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## violation (Aug 20, 2006)

Only decent JCM900 I've played is the SLX, which happens to be my step dad's. The rest? Pass.


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## 4x12 (Feb 25, 2008)

I evolved from a Marshall 8100 to a JCM900 HGDR 100w head and that amp almost made me stop playing. I loved the 8100 but I had to sell it to pay the 900 half stack and man I couldnt get enough gain out of that thing. If I wanted to play acdc & aerosmith kinda stuff it would have been ok but thats it!! When I hear people say it's got a shit load of gain seriously makes me stop and stare. Took me a while to come to realise I bought a piece of shit because of the love I had for Marshall. So I eventually got a Boss GX-700 and used the 900 as a power amp for the GX-700 and I finally had gain... I moved on to rack gear after that until I picked up a DEAD mint 5150 and Marshall 1960a for $750

Word of advice dude, don't even bother with the 900... pass and keep going. If you're looking for gain check out a 5150 II with dual EQ for the clean and gain
channel. Much better investment.


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## µ¿ z3®ø™ (Apr 29, 2006)

4x12 said:


> Word of advice dude, don't even bother with the 900... pass and keep going.


well, that just about sums it up for me too.
to my ears, the 2203/2204 are so much better sounding than any JCM900 that i've ever heard that the few hundred $$$ more for the JCM800 makes it seem like a bargain.

want a totally kick-ass JCM800 that is hand wired and has ungodly great touch response? look around and be patient for the Dr. Zed SRZ65LE. there were not many made and they sold for a bit over $1500.00, but they are well worth seeking out. different sounding than my germino JTM45 'clone', but equally as great an amp for much less. 

word of note for the JCM800s and 'clones'. they are not super high gain amps. cranked out they will have a bit more gain than most plexi amps, but they take OD pedals very well and seem perfect for those few songs when a bit _more_ is needed. 










i think this pic might be the entire production, save for ten, of the SRZ65LE amps from the doctor.


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## SinCron (Mar 2, 2006)

4x12 said:


> I picked up a DEAD mint 5150 and Marshall 1960a for $750


And now you have what Quo Vadis uses.


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## Budda (May 29, 2007)

from my experiences with my buddy's JCM900 halfstack (that he paid too much for - i forget which part was brand new, the head or the cab lol) they sound good. i'd like to try boosting it to see how it handles higher gain then punk.

my buddy and i got good sounds from his.


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## 4x12 (Feb 25, 2008)

SinCron said:


> And now you have what Quo Vadis uses.


couldn't tell you... I don't listen to them. But I can sure as hell name off many other bands that used and still use the 5150's if ya need!
But i still prefer my ADA & VHT rig.


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## SinCron (Mar 2, 2006)

4x12 said:


> couldn't tell you... I don't listen to them. But I can sure as hell name off many other bands that used and still use the 5150's if ya need!
> But i still prefer my ADA & VHT rig.


I meant the amp and cab combo. They use both of em together. It's Technical Death Metal. Fun stuff. 5150's are lots of fun and that's why I'm getting the blatant ripoff. The only thing about it is a better clean channel and more bass. Two things that amp really needed. Mmmmmmmmmm. 7 string and 5150 clone. What would I do with that........ Fear Factory?


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## Budda (May 29, 2007)

a 5150 needs more bass?

*blank stare*


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## JSX/6505 (Nov 18, 2007)

Peavey's come from the factory biased relatively cold. The JSX and 6505+ have bias trim pot dials next to the power tubes. Turning this dial counter clockwise makes these amps sound thicker and hotter.


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## sesroh (Sep 5, 2006)

I had a JCM 900 50 watt head. It was an SL-X model with 5881s I believe. I liked the sound but it wasn't for me. I realized I'm not really into Marshalls and only the gain on it was usable to be. The clean was okay, but not great.


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## 4x12 (Feb 25, 2008)

sesroh said:


> I had a JCM 900 50 watt head. It was an SL-X model with 5881s I believe. I liked the sound but it wasn't for me. I realized I'm not really into Marshalls and only the gain on it was usable to be. The clean was okay, but not great.


Well the SL-X was never really meant to be used for cleans and that could explain why you didnt like em to much. On my 900 hgdr the cleas was very nice but the gain lacked big time. I was told originaly that the SL-X would have been the amp to take but I wouldnt listen.


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## jmaysen (Mar 10, 2008)

*900's the great the bad and the ugly*

900's are not all equal

the worst is the 50w dual channel, horrible sounding in any configuration. reverb sounds like crap. 

the ok stuff is the 100w dual channel, again the reverb is crappy. I never was a fan of ch switching amps anyway.

the better is the 900 SLX 100w head. If you can't play it clean it's because you never figured out what the volume knob on your guitar is for....

but by far the best 900 amp is the 100w 2100 pre SLX with only 3 ecc83 tubes. Nothing is more crunchy and nasty. it truly is what the Marshall sound is about. These have DUAL MASTERS, not dual channels. Dual masters as in LOUD and LOUDER! great for lead players those who know how to use a guitars volume knobs. And no crappy reverb to get in the way of pure sustaining tone! 

I have a 100w head and 1x12 combo with this amp. They're a lot of fun, but it's not for the inexperienced player. You have to be a dynamic player to get everything out of it.


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## sesroh (Sep 5, 2006)

I could just never get the right sound out of mine. I guess if I played metal or something it would have suited my playing but I could never get the same sound out of it. Sometimes it would sound great and then other times I'd always be playing the the knobs to find the right sound. Other than that they're okay. Good for the price anyway.


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## jmaysen (Mar 10, 2008)

to get the best tone out of a dual ch 900, put all the knobs at 12 o'clock (turn off the reverb, yuck!), master wide open, bring gain up to taste. Do this with both channels.

For the Dual Master series, do the same with the tone controls, everything at noon. One master at 6, the other at 9. (step on footswitch when you want to rip into a lead and not be droned out!) now these amps have dual gain knobs, one acts with the other. It's pretty cool once you figure out it's not about distortion, it's about drive. I can make my 900 sound like a jazz amp with the master wide open and the gains at 90%. it's all bout playing with the volume on the guitar and controlling how you pick.

if your 900 doesn't sound good with these settings, get new tubes or buy a better guitar.


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## Greg Ellis (Oct 1, 2007)

I had the opportunity to play a JCM 900 50 watt dual reverb head into a 4x12 for several hours at our reunion jam on Friday. EL34's as far as I could tell (I didn't take the back panel off or anything).

The amp really wasn't feeling well, it had issues with the output (and gain) surging way up and then way down (all by iteself). Maybe a failing preamp tube or something, I don't know. It definitely needed a once-over from a tech. It took a few hours to really settle in and work like it ought to. It may have been sitting unused for a long time, I don't really know.

When it was working, though, it was quite pleasant. On the rhythm channel, I was getting some really nice rich belltones, especially on my neck pickup, which is fairly tame (about 2500 or 3500K, IIRC).

As someone mentioned, chorus helps a lot. I was using a borrowed Marshall Supervibe Chorus set slow and subtle and it sounded great. We did Comfortably Numb and Wanted Dead or Alive and Bad Company's Shooting Star and a few others in the same vein - I was very pleased with the amp's ability to recreate those lead tones on the rhythm channel. Billion Dollar Babies and Sweet Emotion sounded good as well.

Later on we cranked up and played some Ozzie and Maiden and Sabbath and Dio, etc. With the master close to wide open, the lead channel was great. Very loud, really meaty. I couldn't get the amp to sound nearly as nice at a lower volume. Aside from the obvious lack of TLC, the only issue I noticed was a bit of shrillness in the treble that I couldn't seem to dial out without losing too much - I think an eq would have been handy (didn't have one). Other than that, it was making just about exactly the sort of sound I was looking for.

I also noticed that the effects loop was a bit buzzy - not sure if it was a problem with my cabling, or with the pedals or with the amp itself. It wasn't a huge issue, just a bit humerous to listen to the buzz getting "chorussed" in between songs.

I must admit that I haven't played a whole lot of amps, not in the past 20 years anyway, so maybe anything would make me happy? I don't know.

It seemed a decent amp to me. Too loud to be useful in a bedroom or basement application - it didn't sound nearly as good at lower volumes. But for a "heavy hitter" type drummer (both of the drummers at the jam are pretty loud) it was just about right, maybe only a touch too loud. I'd be curious how it works with a bit of post-power-amp attenutation (hot plate or whatever, just enough to tame the volume a bit).

The 25 watt mode didn't sound very good to me. I'm not sure how they achieve that? 50 watt mode was better.


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## Guest (Mar 23, 2008)

The 900 has its pots soldered to the board instead of hard wired liked the 800 series had. It was to cut costs. Over time the solder joints break and need to be re-touched periodically. Its a different sound as well but that can be fixed just like the potentiometer problem, otherwise its a Marshall. 800s were simple but a one trick pony to say the least. 900s weren't much of an improvement.


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## taskforcestudios (Dec 21, 2007)

*Jcm900*

Of the JCM900s (or most JCMs for that matter) I've played, I haven't been super impressed with them. They are not bad sounding amps by any means, especially if you can get them for a good price. If anything, I'd say go for an SLX if you can, as previously mentioned in this post.


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