HomespunEffects
Roadie
- Messages
- 183
I have a 1967 Fender Bassman.
I traded a Mesa Dual Rectifier (non-multiwatt) for it.
Recapped it, even some of those blue (supposedly bulletproof) tone caps were out of spec. I think this thing must have been underwater or something. Just about every component needed replacing. All but 3 carbon comp resistors were out of spec. Some were cracked in half, some turned to powder when you touched them. I have no idea what would cause that. It got to the point where I just got frustrated checking every component and having each one fail. I got like excited or relieved when 3 of the resistors checked out then I figured I should replace them anyway as they are sure to fail as soon as I reinstall the chassis into the head shell.
I tried to use the polarity switch to change the NFB resistor but it just made it sound like garbage. I ended up just finding my favorite value and removing the switch mod.
Instead, I wired in a Mids pot where the switch was and that really woke this amp up.
I also changed the grid stop resistors from 68k to 22k in hopes of reducing some of the hiss inherent to the resistors at the input to the first tube stage.
It was a lot of work but I’m happy with the results.
I think my next mod will be to install an effects loop where the Bass channel input are.
I traded a Mesa Dual Rectifier (non-multiwatt) for it.
Recapped it, even some of those blue (supposedly bulletproof) tone caps were out of spec. I think this thing must have been underwater or something. Just about every component needed replacing. All but 3 carbon comp resistors were out of spec. Some were cracked in half, some turned to powder when you touched them. I have no idea what would cause that. It got to the point where I just got frustrated checking every component and having each one fail. I got like excited or relieved when 3 of the resistors checked out then I figured I should replace them anyway as they are sure to fail as soon as I reinstall the chassis into the head shell.
I tried to use the polarity switch to change the NFB resistor but it just made it sound like garbage. I ended up just finding my favorite value and removing the switch mod.
Instead, I wired in a Mids pot where the switch was and that really woke this amp up.
I also changed the grid stop resistors from 68k to 22k in hopes of reducing some of the hiss inherent to the resistors at the input to the first tube stage.
It was a lot of work but I’m happy with the results.
I think my next mod will be to install an effects loop where the Bass channel input are.
