Missing Parts on my SuperLead Board?

zeeb · Post by **zeeb** » Sun Sep 12, 2004 3:20 pm

Hey all ---

Just wondering why there are some caps missing on my board...(see right hand red arrow on pic below)?? Its a modded '72 head i run into two 2x12s (four late sixties celestions) -- sounds great. Just wondering what some of the additions (see other red arrows) may be doing.....

thanks for any info --

John Lee

Post by **VelvetGeorge** » Sun Sep 12, 2004 5:09 pm

From left to right:

are those capacitors? Normally these are added to kill occillation. You find them in Mesa Boogies. Seems kinda odd.

A trimmer pot on the grids of the pahse invertor? This is also strange. Most likely done to balance the PI. Usually you lower the value of the 82k plate resistor.

No snubber caps. It's common to not have them. Unless popping is a problem wmeh you hit the standby, I wouldn't worry about installing them.

George

zeeb · Post by **zeeb** » Sun Sep 12, 2004 6:55 pm

hey george --

att. below is a close up of the resistor addition.... i'm not really up on all this technically --- i've been curious how these things altered the
tone... whatever they're doing, it works! got a set of 4 mullards in
there and some great sounding 12ax7s --- think the extra trim pot may
have been to change between two settings if i changed the phase inverter (?) valve.... if that makes sense.

this is the same amp that has the voltage reducing mod .... need to lose that really.

thanks for your info,

j.