Marshall JCM 900 2100

This review is for the JCM 900 2100 High Gain Master Volume MkIII 100 Watt model that Marshall launched in the late '80s/early '90s - not to be confused with the later 2100 SL-X model.
Also, this amp has ABSOLUTELY NOTHING in common with the dreadful Dual Reverb models (aside from sharing the "JCM 900" name).

Basically, this is a straight forward, no frills 1-channel amp in the 2203 tradition, but with two selectable and footswitchable Master Volume controls (i.e. volume levels), the usual Marshall EQ - Presence/Bass/Mid/Treble and both a control for "Preamp" and "Gain", effects loop, pentode/triode switch etc.

Sound quality is really good - no matter what guitar/pickup. Sounds also very good with all kinds of pedals.

2100 vs 4100

The 2100 has more than enough gain for even the weakest single coil PU's and I disagree with prior poster "danny" - the 2100 has way more gain than any unmodded 4100 DR POS will ever have, and most of all, actual TONE.

2100 vs. 2100 SL-X

The biggest difference between the 2100 and the 2100 SL-X is the noise. The 2100 is very quiet for its amount of gain. On the other hand, the 2100 SL-X doesn't have that much more gain, but a whole lot more noise. Also, the 2100 can easily be dialed in to have a great, dynamic "cleanish" sound with a touch of "hair", while still having plenty of volume, something you won't get with a 2100 SL-X.


To sum it up - if you always thought that the 2100, bearing the JCM 900 name, sounds lame or has the same type of distortion as the 4100, then you owe it yourself to check one out if you happen to get the opportunity. For me, the 2100 is pretty much an evolution of the 2203 model. But contrary to the 2203, you won't need the use of a stompbox to push it to heavier overdrive/distortion, especially with SC pickups.

Except for some basic maintenance (cleaning pots, replace tubes etc.), zero problems in 19 years.

Great amp. Period. If you can find one in good shape, get it. Aside that they sound great, these models will definitely go up in value in the long run.

The Marshall Jcm900SL-X Model 2100 Mk.IV is the 100 watt master Volume 2 channel model with a High Low Mode switch to choose between 50&100 watts.Direct in, effects loop, valve failure fuses with LED's,This is the metal or thrash model with 4 12AX7's and 4 EL34's front panel has of course an "On" button next to the standby button next comes foot switch input with LED.Then the EQ Presence,Bass,Middel,Treble. Then 2 volumes (B) & (A)then Gain then Preamp Volume and then the input.I mostly play metal or rock so this is why I picked this amp.This is not a Jazz or country amp unless you like a lot of overdrive as you do some chicken pick'in.

If your looking for say a KIss sound this is the amp for you.This is the same amp that KISS used (with 1960BV Cabs) for thier reunion tour in the late 90's.If you like the sound of early Slash then your in luck.This is one of the amps he used.With this said.This amp is made for Rock-N-Roll,Metal or Blues Rock.True Marshall Tone.I play a PRS 513 Rosewood through mine.oh! Clean this is not this amp is mainly for overdrive.

I've never had any problems with this amp.I would depend on it for any gig in the future.Don't forget you can switch between 50&100 watts.beside you'd most likely mic it anyway.

The little I've dealt with them they where very friendly and professional.By the way it wasn't for this amp.But an Early JCM800 combo I had.

The only reason I don't rate it as a perfect ten is that I need another amp for a good clean channel.Good for me I own a TSL100 & a VHT Deliverance120.Both have a super Clean sound. so I a/b them when I need to.Matters on the music I'm playing at the moment.But if all I play is dirty I don't even have a backup.Just this.It's become my main amp.

i have a marshall jcm 900 2100 mkIII. its a 1990 model(one of the first friggin a). if you want a good clean channel stop reading, an "acceptable" clean channel does not exist in this beast. but thats fine if you have an a/b box and another amp with a dedicated clean channel. features are pretty well covered in previous reviews.

i beleive henry ford said it best "you can have it in any color you want as long as its black". that rings true hear as well. you can have any tone you want as long as its distorted marshall tone. one thing id like to make clear how ever is all the reviews ive seen around comparing this model to the dual reverb models. thats comparing apples to oranges folks. the 2100 series and the 4100 series are two completely different pre amp circuits. the 2100 series pre amps read as follows in--v1 stage1--vi stage2--v2 stage1and 2 tied together--diode clipping

the 4100 preamp reads as follows in--ic gain boost--same as 2100 series exceppt diff plate rest. values
so with that cleared up yes the 4100s have more gain out of the box but most of it is not tube gain rather s.s. gain. the 2100 series are more traditional marshall sounding but less gain than the 4100s.

which brings us to "How brutal is the distortion?". stock, its not brutal distortion its crunch, however ive modded my entire pre gain structure and has seemed to do the trick. it added more pregain distortion and a little more low end response. DONT TRY TO PERFORM ANY MOD TO A TUBE AMP IF YOU DONT KNOW WHAT YOURE DOING!!!! there is hazardous voltage inside that could kill you and must be properly discharged before repairs or mods.

it is one of the quitest amps ive ever owned in reference to hum and feedback at high volumes. i play metal and it suits it even left stock.

reliability is yet to be seen. havent had it very long and have modified marshalls tested and proven circuit design(if it had a warranty still it would so be voided) NEVER GIG A TUBE AMP WITH OUT A BACKUP OR AT LEAST EXTRA TUBES!! tubes like light bulbs have a varied life time. you never know when theyre gonna fry.

called them for owners manual info and they sent a copy for free!! i give them an 100 for this

ive benn playing for eight years and own countless other pieces of equimpent. if it were stolen id cry then wipe my tears and go hunting for c$%# suckers with sticky fingers and taking no prisoners. i still wish even after mods that it had more distortion. i knew imediately that this was the marshall model i wanted.

This is a marshall 2100 made in 1991. The amp is not versatile but works perfectly for the the type of music that I play (metal). There's two channels, but the second channel, B, is essentially just a volume boost - very cool for solos. The gain goes to 20. This amp is extremely loud. It has an option in the back to change from 100 watts to 50 watts. I always keep it on 100 watts.

I'm using the 2100 in conjuction with a 1974 Les Paul Standard with two seth lover pickups. I'm also using the 2100 with a model 5A Charvel with a J95 in the bridge. The les paul and charvel sounds glorious through it. While I love playing metal with this bad boy, it can also do rock music to a tee. By playing around with the gain and preamp controls, one is able to go from playing SRV to Emperor. If you want fender cleans, this is the wrong amp for you. I on the other hand love the dirty cleans which is achievable by turning your volume down; it provides a dirty clean which Marshall is renowned for. The distortion can get pretty brutal ala Slayer when both gain and preamp knobs are dimed. I like to keep the gain on at around 18 and the preamp volume at around 8. When boosting with a ts-9 or sd-1, one can achieve a brutal crunch that's not over the top, just perfect.

I've owned the amp for about 5 months now and there's been no problems whatsoever. I would definitely use it on a gig without a backup.

I bought it used so I wouldn't know.

I've been playing for roughly 10 years and I have tons of gear. I own a Traynor YBA-1, Marshall 8100, various fenders etc. If it was stolen I would search the world over for another one. Unfortunately, they're not too easy to find. They only made them from 90-92. I love the fact that the amp is simple. I don't find myself screwing around for hours on end trying the find a sound that I'm confortable with. I love one channel amps and guitars, they fail to give me a headache - which is a mighty good thing since I hate headaches.

This one is the MkIII-edition of the 2100-head.
Features - very simple, don't think I have to go through it again, read below.
This is a high-gain amp, don't even try to get a more clean sound, it sounds like shit then. I would like a clean channel aswell.

The sound is crunchy, very crunchy. I think it could be cool to play 80's thrash-metal with, maybee stoner-rock or old hardrock like Black Sabbath from the seventies could work aswell with this amp. That's about it, this is a high-gain amp with a very crunchy sound, not the thick and warm marshall sound I am looking for. With little gain it sounds like crap I think, not good at all, so if you want this one to sound ok you have to play it with a lot of gain, and if you want brutal marshall-gain I think the SL-X sounds much better.
I use a Gibson SG standard.

Acted a little weird when the first week I had it, but after that I didn't have any problems with it. Had it for 8-9 months and I never switched the tubes.

Never tried to gig with it. Tried to record with it once but it sounded like crap so I used a jcm800-2210-head instead. I love the marshall-sound but there are many marshall-amps who is better than this one. Although I think it sounds better than marshall-amps like dsl, tsl, valvestate, 6100LM... I had this one for 8-9 months, then sold it and bought the SL-X instead.
If you want the thick and warm marshall-sound, buy the jcm800-2210. If you want brutal marshall-gain, buy the Sl-x. Check out www.erikhansen.net for sound-samples, yet I think his amp sounds better than mine did.

I was told by another guitarist, whose sound I admire, to look for the early production runs on this particular model, specifically, mine was manufactured in the last quarter of 1989, so it was one of the very first 2100's made. This model represents Marshall getting back to the basics, which dictates no need for features. The simplicity of rock guitar was born from the elder siblings of the Marshall family of old, none of which duanted a behemouth list of features. If you want features, go car shopping. If you want ear bleeding tube saturation, buy this head. The versatility should come from the artist, not his equipment.

I play a Ibanez JPM 100 that has a Dimarzio Air Norton at the neck and Dimarzio Steve's special at the bridge, and I also play a PRS SE Soapbar with true P-90's, and a Fender Strat (Eric Johnson sign.) with Texas Specials. My choice in guitars are specific to my choice's in music genre. The only effects I loop in front of the pre-amp are a TubeScreamer, a compressor, a digital chorus, a crybaby wah, and a digital delay. I've been a working guitarist for over 30 years, and can manage the sound of every guitarist I cover with this configuration. My settings on the head are standardized (L-7, M-scouped, H-8, P-7, G-Full, MV-Full) and the same for every guitar. The shape and modeling come from the effects, and the guitar levels. I've covered everyone from Tony Iomi, to Randy Rhodes, Zak Wylde, Glen Tipton, George Lynch, SRV, Jeff Petrucci, Neal Schon, Alex Lifeson, Ronnie Montrose, Jake E. Lee, David Gilmore...goddamn I'm an old fucker. You get the point, this head puts whatever sound I need, at MY fingertips.

I've been gigging with this particular head for 15 years, and have replaced the tubes and rebiased 5 times, but I'm talking MANY hours of club abuse here, in addition to roasting the last 3 sets of tubes through a power soak every night, so they have melted down quicker than the previous 2 sets, but that's okay. I dig the growl. I'm only giving it an 8 because of the goddamn tubes, although I love the goddamn tubes, and if it didn't have them, I wouldn't even own the goddamn thing. It still just gets an 8.

Haven't needed it. I have the best tech in the midwest. Marshall hooked me up with a manufacture date from the serial no.when I called them in 1991, since then, I haven't needed them.

I'm an old man that still shred's daily, but don't let my age fool you. The poor bastard that decides to steal my gear will be found, and then shot and given a severe limp for life. If he shoots back, he dies.

The tone is unequaled if your heroes played rock guitar from 1967 to present day. Damn things a bit heavy, but that's the roadies prob.

I've played them all...there is no other choice for me.

This amp is pretty much as simple as anything gets, no Mesa/Boogie gadgetry here. To sum this section up quickly if you want to rock and if you cannot be bothered with endless knob-turning this amp is definately for you. Maybe an extra gain knob to go with the two master-volumes would have provided a little more versatility but it's no problem for me. I'll get back to this however.
I'll give it a nine because as good as I think this amp is(rock of all kinds and agas),it is hardly appropriate to call it versatile. On the other hand it's a Marshall! They invented the sound of rock, others are just imitators (some good, some bad).

As mentioned elsewhere on this page this is essentially a one channel amplifier with two master-volumes and a switch. I mentioned above that I would like an extra gain knob because when I hit the lead channel the sound gets a little too dry and I really lack that last bit of saturation of my sound. However, I effectively solved the problem by using a Boss Bluesdriver(any overdrive unit with a simple layout will do), and engaging it with it's level fully cranked and it's gain completely off. This will drive the pre-amp section of the amp harder without coloring or compressing the sound significantly, resulting in classic 80'ies screaming lead. By this simple addition you have four very useful sound to choose from crunch to screaming leads worthy of Eddie or Slash. I'll award it with a ten because if you do not like this amp's sound you aren't likely to be in the market for a Marshall anyway. Remember freinds: There is no such thing as the perfect amp. Every guitarist has a different set of ears so try as many amps as you possibly can.

Things eventually break if you use them often enough. So what!? That's why they have repair tech's.

I have my own technician.

I work in a guitar store so I've had the opportunity to try out a lot of amps. I think what puzzles people is that the Marshalls are so much cheaper than say: Orange, Mesa/Boogie, Fenders. I have so many customers who ask for a lead tone "like on the album (with whatever artist)". These guys spend tons of money on little stomp-boxes without realizing that most of the solos they hear on their records are made with Marshall equipment and that it is stupid to think that you can believably replace a fullblown Marshall with a stupid little transistor box. Why haven't people figured this out yet?!
I've tried this amp alongside the so-called Orange 140 watts dual lead. The Orange costs six times the price of the Marshall because it's hand-wired. I don't give a rat's ass about this, the Orange when comparing sound and price has appallingly little "muscle" despite its 140 watt tag and compared to the Marshall it sounds like a bad plagiate. The morale? Buy with your ears! Don't assume that just because you buy expensive equipment you buy the best. Good luck!

Made in 1990. Single channel with 2 master volumes, switchable, effects loop, 2 speaker outs 8 and 16(4) ohm, standard Marshall fare. This amp has never let me down. Bought it back in the mid 1990's used. Loved it from the first time I plugged in to it. I've used it gigging and just messing around at home. Fits my style perfectly. This amp was pretty much the next generation of the JCM900 2203 with the addition of some preamp clipping diodes and few resistor changes (2 or 3 positions).

I can go from nice JCM800 type tone to screaming overdrive just by turning up the gain. It sounds great with all of my guitars, Fender Strat, Kramer Baretta, homemade dual humbucker strat, Epiphone LP. It started to get noisy recently so I took it in for service. New tubes and a rebias took care of that. Sounds SWEET now. The guy who serviced it complimented on it as well. He said this is a very good amp.

It's a tank. Has never broken down on me at all. I gigged with it for several years without a backup and would do it again in a drop of a hat. All of the tube sockets are hardwired, not PCB mounted (saw this myself) so I have no worries about a PCB melting due to too much heat.

Only dealt with them once trying to find out when in 1990 it was made. Got a reply within 2 days via email. Unfortunately there isn't a way to tell the month. That's OK with me. At least I know I have a first year run of this baby.

Been playing for almost 20 years. I also own a Crate GX-15 practice amp, a few BOSS Pedals, Fulltone DP-1, Rocktron Intellifex rack processor, Crybaby Wah, Phase 90, and a sure wireless. I'm sure I'm missing something. I mostly play this at home from time to time. I plan on taking care of this amp for a long time. I'll take this over the new JCM2000 or a 5150 (had one of those too) any day of the week. The tone is just wonderful. Put a SD-1 in front of it and it screams. This is the perfect amp for my style (EVH, Zakk Wylde, Great White, etc). It covers all the bases. I don't care that there is no reverb. I've gotten used to playing dry. If anything it makes me clean up my picking. If you find one of these models used, snag it. You won't be sorry.

Standard fare as with the other comments made, but will blow the 4100 away without a problem. I've ran both in a stereo configuration and the 4100 just can't hold the mustard. Run it pumped and clean with an effects system and you'll never have any trouble, once you've dialed it in.

I've used Gibson and Jackson guitar's and both have humbuckers. I don't use single coil, so you're on your own in that area. It's a very metal amp and if you want vintage Sabbath tone, it's able to deal with that and then some.

I've gigged with it and no trouble. Had to replace and bias the thing once, but after punishing it for a long time.

Haven't had the need to deal with them.

I've been playing for over 15 years now and want another 2100 to replace that 4100 for stereo stacks. Wouldn't matter if I had to have it overhauled a bit, because it's worth it. If it were stolen, I'd have to kick myself in the teeth for not being able to catch the guy trying to run with a 50 lb. head in his hands.

This rig has the benefit of two completely separate channels for volume; One for "rythm" or accompaniment and the other for solos. It is all very basic withing itself (a separate effects unit is required for color, etc. but has the benefits of cutting out a second Marshall head (via A/B switching) for this purpose. It also has the switching between 50/100 watts.

For my particular sound/style I prefer to run the amp as clean as possible while simultaneously running separate effects through it as the amp itself is designed for classic Marshall sound/voicing and straight up volume... which is fine with me.
It is a very quiet tube unit compared to many other brands I have plugged into since the mid-seventies.
It has CLASSIC Marshall tone, that great "brown sound" with brilliance and excellant voicing; To get an idea of it's overall tone listen to LADY RED LIGHT by Great White, or Ronnie James Dio solo stuff.
I LOVE this amp and will NEVER part with it!
It goes from chrystal clear sweet-to-bad-assed mean and nasty in no time flat. The tube-quality just makes my sound LITERALLY sizzle and burn.

I have been playing for over 30 years. It blows All of the competition away. Period.

It's a f*#kin' 100 watt Marshall tube head.

Need I say more?