JCM 800 horizontal vs vertical input jack differences

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paulyc

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Can someone please tell me what (if any) differences there are between these two amps other than the horizontal jack amps have the pots and jacks mounted to the board ? I read there is a difference in filtering too. I have a horizontal input 2203 and it sounds great, can someone explain any other differences ? Thanks !
 
Thats pretty much it really.

My local shop is owned by one of the best Marshall experts in the mid-west and he swears his horizontal input 800 is one of the best hes had.

Having said that he doesn't believe in using pedals & he likes alot of honky stock pups that ive tried and cant stand but as far as the facts he knows his shit.

But you know as i do you can have 10 of the same amps in the room and each one can sound different.
 
The switch to horizontal inputs was due to the pots being mounted directly to the pcb. Also, IIRC, the 100 watters received less filtering.
 
2204 = I believe no major differences aside from PCB mounted jacks.

2203 = PCB mounted jacks and reduced filtering.

Also, probably some voltage increases in later year JCM800s.
 
They changed the arrangement with the dropping resistors on both the 2204 and the 2203 when power transformers and voltages where standarized at the same time.

On the early ones you have 260v on the first filter node, for a year or so they made a version with only 200v here, and then when new standards came into play the voltages where att 310v.

Higher voltages makes the amp sound stiffer, tighter and brighter.

And of course, the nummer of filter cans on the 100w and pcb-pots. Those are all the differences if we do not think of the various export models.
 
I've owned several each... the structural differences already mentioned aside... buy whichever sounds best.

:rock:
 
I have a 100 watt horizontal, just want to know what the actual circuit differences are and how/why that affects the sound. I knew about the PCB mounted components, didn't know the other stuff...
 
paulyc":2ekkbrgv said:
I have a 100 watt horizontal, just want to know what the actual circuit differences are and how/why that affects the sound. I knew about the PCB mounted components, didn't know the other stuff...
Click to expand...

There are a lot of twists and turns with these, especially when you factor in the switch to 6550s around 1984 for the export models... then then the Canadian models had additional internal fuse networks and pcbs to meet Canadian CES laws... it's really a thing where you need to have seen a bunch or played a bunch and pick your favorite. The late '70s JMP 2203 are near identical as well and often overlooked. Many of the originals have had the Daly 50uF caps replaced with either FT or JJ caps by now which many think changes the sound... so it's a crap shoot at best. The majority of the circuit has remained unchanged since the introduction of the JMP 2203.
 
-well one thing is certain with Marshall, and that's that nothing is certain.
 
Keith at RedPlate has a horizontal input 2204 that sounded phenomenal. That said, the Magica kept right up with it.
 
I have a late 70s JMP also a 2203 and both sound great to me.
 
The 2203 went from 6 can caps up until 84, then 5 in 85, to 3 in 86-90. 2204s didn't change the filtering at all as far as I know.
 
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