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O100JM transformer in a 2203

Posted: Sat Jan 20, 2007 12:49 am
by HIn
Would a MM 0100JM transformer work as a replacement for a marshall JMP 2203 amp.

Posted: Sat Jan 20, 2007 10:53 am
by Guitar Adjuster
Dont' know about the MM but I used George's clone Heyboer in a 2203 and it sounds great, better then the original 80's 2203 tranny. I would guess the MM would sound equally as fine.

Posted: Sat Jan 20, 2007 11:55 am
by VelvetGeorge
The O100JM does sound great in a 2203. There is also a O100JM-M that is tweaked for higher gain and works with 6550's and KT88's.


george

Posted: Sun Jan 21, 2007 1:28 am
by joshwilson3
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Posted: Sun Jan 21, 2007 8:07 am
by Flames1950
"Marshall" never put a different output tranny in for 6550's, and in fact "Marshall" never put 6550's in the amps of their own accord anyway -- the distributor forced that upon them. And it's not real clear whether Marshall even did the conversion for the distributor -- most books make it sound like the distributor did the changes themselves but I don't know if that is true or not (I wasn't there. :wink: )

Posted: Sun Jan 21, 2007 5:55 pm
by VelvetGeorge
AFAIK, the 1.7-1.8K primary impedance has not changed since the Dagnall 1.5" OT's started showing up in late '67. So there was not a change for 6550's.

VG