Pending NAD…’76 Marshall JMP 2203

[team13chad]

Countdown to NAD.

I got this 1976 JMP 2203 for a very fair price and plan on giving it to my beast of a tech to clean up, go through, probably retube, and certainly replace the main power cable.
I have some JCM 800s and this will be my first JMP.
This one supposedly had a “Bias King” mod done by Steve Wilson and has two of the


I see some other holes and odd things that im unclear on.


feel free to educate me on what to expect from this amp vs my 800 2203 and let me know your thoughts on any other odd things you may notice about this one.

 

[Racerxrated]

You’ll probably have some mustard caps in there; it might have more of a vintage tone than your 800; the 800 might be more aggressive. That’s a first year MV Marshall; the 2204 from 76 was different in that it didn’t have the cascaded gain like the 2203. But simple to mod it. If you didn’t have a tech to go over it I’d recommend you find one. With those holes who knows what’s been messed with. But a cool amp and find!
Congrats!

 

[dirtyfunkg]

FWIW I had a Canadian 1977 2203 a few years back that had four speaker output sockets in the back. That abandoned socket was probably a speaker output at one point. As to why it's abandoned... ?

The front hold to the far left is interesting, though... probably a PPIMV but you guess would be as good as mine.

 

[braintheory]

I’ve not tried one from ‘76, but the ones I’ve tried from ‘77-‘79 all sounded great to me. I’ve got a ‘79 JMP2203 myself. I generally like them more than the JCM800’s. They have typically more growl and warmth, while 800’s are usually a bit tighter, faster, but can also sometimes be brittle compared to the JMP’s and I like the more complete growl of the JMP’s. They sound really great with the right boost (like a Klon), better to my ears with that overall to any modded ones I’ve tried, even cameron, but ymmv and those mods vary

 

[team13chad]

You’ll probably have some mustard caps in there; it might have more of a vintage tone than your 800; the 800 might be more aggressive. That’s a first year MV Marshall; the 2204 from 76 was different in that it didn’t have the cascaded gain like the 2203. But simple to mod it. If you didn’t have a tech to go over it I’d recommend you find one. With those holes who knows what’s been messed with. But a cool amp and find!
Congrats!

Thanks! And yeah I have a really good tech who is going to give it a deep clean and go through it all.

 

[Deleted member 26052]

Very cool, looking forward to seeing the after pictures.

 

[Samhain]

Going to need a cap job, your filter cans are bulging. Replace the bias filters too.
Gonna need some work.
Make sure you get a Pro those ST-1 PCB's are super easy to fuck up. Have to pull all the pots & flip the board to do it right.
For me a 100 watt amp missing 2 power tubes is a red flag as God knows who did what to that amp.
Could be nothing/could be not good, hard to say.
The JMP's are really getting old, last couple of years ive seen looks like the bottom of the barrel.
No surprise really. They all wern't taken care of well.

 

[team13chad]

Going to need a cap job, your filter cans are bulging. Replace the bias filters too.
Gonna need some work.
Make sure you get a Pro those ST-1 PCB's are super easy to fuck up. Have to pull all the pots & flip the board to do it right.
For me a 100 watt amp missing 2 power tubes is a red flag as God knows who did what to that amp.
Could be nothing/could be not good, hard to say.
The JMP's are really getting old, last couple of years ive seen looks like the bottom of the barrel.
No surprise really. They all wern't taken care of well.

All great suggestions. I’m going to relay the above to my tech who will get it done. I may order a sourmash head shell for it too. Once my dude gets done with it, some fresh tubes, and a new headshell, it’ll be right as rain.

 

[harddriver]

Congrats on the amp, the filter caps do look like they are bulging, I recommend ARS 50/50uf caps.

Amp looks kinda rough but sometimes those are the ones with Mojo! I also find 77-80 JMPs to be very consistent and sound awesome IMHO.

My 79 had the red lego caps on the original ST-1 Marshall board, that amp ripped for many years!!!! As Racerxrated says the 76 should have mustards caps on the board and the cascade was different from 77-80. Just have your tech look it over and see if it is one of the very early 2203 preamp circuit layout.

 

[Samhain]

All great suggestions. I’m going to relay the above to my tech who will get it done. I may order a sourmash head shell for it too. Once my dude gets done with it, some fresh tubes, and a new headshell, it’ll be right as rain.

This explains & illustrates the subject well.