JMP 2203/2204

CHrisP86

I’ve never had a really old school Marshall and I think it’s something I need to try.

Looking around, the JMP 2203/4 seem to be the best balance being master volume and a bit more user friendly but still a great classic rock sound.

Any particular pros/cons of these over other ‘vintage’ Marshalls?

Anything to look out for when buying them?

What sort of price range should I be expecting to pay? The only one I can see at the moment is on eBay at £1,500.

Thanks

GoldenEraGuitars

Late 70s MV 50 watt JMP... THE sound of rock.

Ive never paid more than £1000 for one is good condition. 

ICBM

CHrisP86 said:

I’ve never had a really old school Marshall and I think it’s something I need to try.

Looking around, the JMP 2203/4 seem to be the best balance being master volume and a bit more user friendly but still a great classic rock sound.

Any particular pros/cons of these over other ‘vintage’ Marshalls?

Anything to look out for when buying them?

What sort of price range should I be expecting to pay? The only one I can see at the moment is on eBay at £1,500.

Way too much. They’re typically about £750-£1000 I think, although I might be slightly out of touch...

They’re the best-sounding Marshalls ever made in my opinion - but they’re not especially rare, and often have been hacked, modded, badly repaired, or simply thrashed, and need extensive work to make them right - so don’t pay even that much unless you know exactly you what you’re getting... a full overhaul can easily cost a couple of hundred pounds, and that’s before putting right any damage. Replaced transformers are also common and make a big difference to the value even if done correctly.

They weigh a ton for a head and are stupidly loud before they really sound great, usually - even with the master volume - although oddly, some work much better down to lower levels. You will need an attenuator to get the best out of one at home and possibly even at a gig unless you play in a very loud band. You also need the right cabinet - a large 2x12” or 4x12”, they really don’t sound best without some ‘room to breathe’ - and enough power handling, they put out a lot more than the rated power, a 50W or 100W cab is not enough.

But if you get a good one it’s the absolutely definitive sound of rock guitar in my opinion.

CHrisP86

Thanks, guys.  Sounds like I'm on the right track then!

Interesting on the cab @ICBM, I might go for the 2204 then to avoid the need for a 4x12 for now.  Wish I hadn't sold my oversize Bogner cab!  I've got a 2x12 with V30's in but was thinking about pairing the JMP with a new cab with G12-65's.

ICBM

CHrisP86 said:

I've got a 2x12 with V30's in but was thinking about pairing the JMP with a new cab with G12-65's.

They're definitely the right speakers - or Creamback G12M-65s and G12H-75s, which are closer to the original Blackback 25s and 30s but with much higher power handling.

Emiel

Argh! Stop it!  One of my (few) regrets was selling a 1976 JMP 2203!

I used it with an old 4x12 with G12-65's and vividly remember that one time when I could finally play it loud. It can sound a bit thin and bright when the master volume is set low. But put it past 3 or 4 and it thickens right up. Sadly, that was only possible on some outdoor gigs! I would love to acquire a 2204 and play in a Thin Lizzy tribute or something like that!

timmypix

Sorry to hijack slightly, but as someone still getting his head around Marshall nomenclature and models - what's the difference between a JMP 2203/2204 and a JCM 800 2203/2204?

ICBM

timmypix said:

Sorry to hijack slightly, but as someone still getting his head around Marshall nomenclature and models - what's the difference between a JMP 2203/2204 and a JCM 800 2203/2204?

There 'should' be no difference between a later JMP and an early 'vertical input' JCM800 - the circuits are exactly the same, it's really just a change in cabinet and chassis styling - but I and most other people who have used both think the JCM800s are noticeably brighter. It must be down to either differences in the types of components used (mostly caps), or possibly the physical layout, which can make quite a surprising difference with these.

Later 'horizontal input' JCM800s have some circuit changes, particularly to the filtering in the 2203, which make them stiffer-sounding.

Earlier 2204s also have lower power supply voltages, which make them a bit softer and thicker-sounding. Very early (1975-76) 2204s also have a very different circuit, without the two input gain stages cascaded, and sound much weaker and less gainy - they were changed to the 2203 circuit almost as soon as it was introduced, which all have the better cascaded circuit.

timmypix

@ICBM thanks! You are a font of knowledge, as ever.

CHrisP86

I did weigh up just going for one of the 20W 800's, to get me in the ballpark, but not sure it would scratch the itch!

spirit7

Any of the late 70s/early 80s MV JMPs or early 80s vertical input JCM 800s will scratch the itch.  I got an ‘83 vertical input 800 a few months ago and it is absolutely cracking.  

CHrisP86

@spirit7 it was the clip you sent me of that amp that started me down this road!

Teacherphil

My JCM800 2204 head at low volumes sounded like an ice pick going through my brain. I honestly thought there was something wrong with it.The louder it got, the more balanced it sounded. I tried it through various speakers. Greenbacks, creambacks. G12H30s. The best I ever got it sounding was cranked up through a marshall 4x12 with gt75s. I eventually did those bright cap mods in the preamp section which made it more usable at lower volumes. I eventually sold it as I got fed up of lugging it to rehearsals and gigs only to be able to turn it up to 3. The 'clean' channel (low input) sounded amazing cranked right up. That warm 70s valve amp sound. The hi input was much brighter and had more preamp gain. It gave that classic metal sound.

TTBZ

A JMP of some kind is probably my dream amp (along with the dream Les Paul custom to go with it!) - the 2104 is probably the best sounding Marshall I've ever played and I'd love it in head format. They definitely have a softer feel and sound than a 2203/2204, not sure why but it's nice and makes them fun and easy to play. With the right boost/drive pedals you can play anything you want on them. Does anyone make a good JMP 50w master volume clone? Like the idea of that sound but with a modern build quality and reliability. The closest thing I've played to that is one of the Bernie Marsden JMP limited run, but they were crazy expensive!

ICBM

TTBZ said:

A JMP of some kind is probably my dream amp (along with the dream Les Paul custom to go with it!) - the 2104 is probably the best sounding Marshall I've ever played and I'd love it in head format. They definitely have a softer feel and sound than a 2203/2204, not sure why but it's nice and makes them fun and easy to play.

The 2204 is exactly a 2104 in head format - it's the same amp chassis. The difference is the cabinet, compared to a 4x12" or a closed-back 2x12".

TTBZ

ICBM said:

TTBZ said:

A JMP of some kind is probably my dream amp (along with the dream Les Paul custom to go with it!) - the 2104 is probably the best sounding Marshall I've ever played and I'd love it in head format. They definitely have a softer feel and sound than a 2203/2204, not sure why but it's nice and makes them fun and easy to play.

The 2204 is exactly a 2104 in head format - it's the same amp chassis. The difference is the cabinet, compared to a 4x12" or a closed-back 2x12".

Oh fair enough, I must have just imagined the difference in tone because the JMP looked more vintagey or something haha. I've spent more time on the 2203x reissue than a 2204 so that's where my opinion on the later 800s sits I guess. It's a shame there's no 2204x. 

TTBZ

CHrisP86 said:

I did weigh up just going for one of the 20W 800's, to get me in the ballpark, but not sure it would scratch the itch!

To be fair they're pretty accurate in sound and you can actually get the master volume up to a decent volume. Obviously a bit more compressed sounding and "smaller" due to the lower wattage, but they still sound huge through a decent cab

ICBM

TTBZ said:

Oh fair enough, I must have just imagined the difference in tone because the JMP looked more vintagey or something haha. I've spent more time on the 2203x reissue than a 2204 so that's where my opinion on the later 800s sits I guess. It's a shame there's no 2204x. 

No, I don’t think you imagined it - I find the JCM800s (even originals) sound brighter than the JMPs, even though the circuit is apparently identical.

But the difference between a JMP 2204 and a 2104 is purely the cabinet, the amp section is exactly the same. I think the 2204 sounds best through a 2045 2x12” cab, in fact - not a 4x12”. With a 4x12” you want the extra punch of the 2203.

They’re small differences though... all of them sound great - and you can get quite wide variations in individual examples.

The best I’ve ever heard was a very early ‘76 2203 with toggle switches, which only the very first had - the best Marshall I’ve ever played, including all the plexis. Remarkably, it had the best master volume as well - it sounded perfectly consistent right down to 2... I have no idea why, they mostly don’t. Unfortunately the owner wanted it back!

bananaman

The reissue is a good bet. It's very well made and a nice one can be had for about £800. I think the difference people hear in the early JMPs vs the later ones/JCM800s is real and is caused by the presence circuit, which is different. In the later amps (and the reissues) the presence set at 0 is equivalent to the control being set about half way up on the early amps. If you 'break' the circuit temporarily by disconnecting it then the amp is noticeably less harsh at lower master volume settings.

ICBM

bananaman said:

The reissue is a good bet. It's very well made and a nice one can be had for about £800. I think the difference people hear in the early JMPs vs the later ones/JCM800s is real and is caused by the presence circuit, which is different. In the later amps (and the reissues) the presence set at 0 is equivalent to the control being set about half way up on the early amps. If you 'break' the circuit temporarily by disconnecting it then the amp is noticeably less harsh at lower master volume settings.

That's right - the presence circuit did change, from using the pot itself as the 'tail' resistor in the phase inverter (which causes DC noise when turning the knob, and erroneously leads to the pot being replaced when it doesn't need to be and won't fix the problem anyway) to a separate resistor with the pot in series with the cap, which is inherently brighter as it still leaves the cap in the circuit at high frequencies, with a value of roughly half the pot on the old version.

But that occurred before the MV models were introduced, so it's not why the JCM800s sound brighter than the JMPs. Even the very first 2204 circuit in 1975 had the separate resistor.

bananaman

Yep I thought that too, but over the years I've had a fair few 2203s and I've seen 3 different presence circuits. One definitely had the 5k pot set up plexi-style (DC noise when you turned the knob), another had a 5k pot but with a resistor network (presumably to shunt away the DC?) and all of the others had a 25k pot and resistor network the same as the reissues. The best sounding one (maybe coincidentally) was the one with the presence pot acting as the tail of the PI.