JMP 2203 differences 1979 and 1980


Hi, after playing some JCM900's and 800's, I obtained a slightly battered JMP 2203, serial number 05027M.

This points to production year 1980.
Can anybody tell me the difference between the 1978, 1979 and 1980 incarnations of the JMP 2203?

And in addition; when relacing the valves, which types and brand should I use?

While we're at it... Where could I obtain the origonal schematics for my amp?

Thanks in advance!

Bye, Ward

edited 11 Jan 2017 at 08:06 AM

Ward van den Berg

asked 11 Jan 2017 at 07:50 AM

Ward van den Berg
Answers: 1



Regarding your question, the electronics inside the 2203 will be the same on all three years you mentioned. Orginially they would have been fitted with 4x EL34 and 3 x ECC83 we recommend good quality valves. We can only send circuit diagrams to registered engineers. 

answered 11 Jan 2017 at 09:59 AM

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