JMP 2203 question

[Johnny]

A quick question:

anyone here know if there's a difference between say a 1983 JMP 2203 or a 1977 JMP 2203? Like do they have different levels of gain or are they the same?

[jtr654]

The early JMP with master volume had 6550 instead of EL34. I have a 1977 50 watt head and 1977 50 watt combo and both have 6550 in them they can be rebias for EL34.

[Johnny]

Oh. Well, thats great since I prefer EL34s over 6550s anyway. Thanks. I bought an '83 2203 100W head.

[oipunkguy]

from my understanding the circuitry is the exact same, just a different look. JCM 800 collectors always seem to prefer the vertical input version, because they are suppose to be made better. the horizontal versions (after 1983) was a cost cutting measure so both inputs could be installed on the same circuit board. I'm not quite sure why that is a big deal, but hey there you go

[Johnny]

Different transformer, less gain. The transformer is only used in teh 2203 JMP making it unique sounding. And mine sounds freakin' great.