Metropoulos Forum

My first and last crack at moding a PCB, from now on HW. This is basically the popular Bluesbreaker (JTM45) mod that is supposed to make this amp close to the real deal, who knows yet? I didn't have anything better to do, so I just used some of Georges's Mallory caps he sent me with my HW kit. Installed a few Spragues, lowered filter cap values 16uF x 16uF & 32uF x 32uF, respectfully, and did some value changes here and there, and so far this is what it looks like. This amp sounded 100% better just changing from the stock 5881's to KT66's valves (Biased 40mA) and installing GT's 12AX7M's in all sockets. This amp was NOT made for the 5881 valves. If you don't want to do the whole mod thing, just change the tubes, and you'll be alot happier camper! Any comments to further this project is greatly appreciated. I've got a colorized schematic with all the value changes if anybody needs a copy. You won't have to go blind, like I almost did, looking at a fine print copy.

Link for schematic: http://img86.echo.cx/img86/9938/1962schematic1fu.jpg

Uh...that board's missing a .1uF coupler in the output section......there should be three .1uF's in a row about 2/3rds of the way across the board, right next to the two bigger black bias caps.
Seriously, good caps on that board with the tube changes you've made and maybe the correct value filters -- that amp should rock pretty damn nicely. Certainly way better than when it arrived at your doorstep.

I was one .1k cap short which is on order. As stated above, I lowered the filter caps with new F&T's to the correct values and will be installing a new tranny, haven't decided which brand yet.

It would cost Marshall Maybe $200.00 to put in good Sozo or Vishay caps, Quality Transformers and good filter caps. I do not understand them taking the Superleads and JTM 45's and disrespecting them like they have done. Piss poor in my opinion. They should have never skimped on these things!!! Bastards!!!!

Dax