Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: plexi50 on January 10, 2011, 07:35:49 pm

Title: Mesa Mark III / Purple Stripe R2 Volume Mod
Post by: plexi50 on January 10, 2011, 07:35:49 pm
I am having a crappy day with this amplifier. This should have been a 30 minute job

I did the R2 volume mod but i get no tonal response from the 250K pot that is replacing resistor R130

All wires,250K pot and connection points that i have done read out connected on my DVM

Here is what i did:

R 130 is lifted at the north end facing the front panel from the back and a wire is soldered on the empty resistor pad

That wire is soldered to the 250K pot outer terminal

A wire is soldered to the right side of R 131 and soldered to the center 250K pot terminal

Are there traces under this board as i have seen in most all the Mesa amps ?

I did a real clean job and i am at a loss as what to do next. Errrr! :lipsrsealed: