Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Yosser on January 01, 2026, 08:29:04 am
-
I'm in the process of restoring and modifying a carlsbro 60 pa reverb (tube) for use as a bass or guitar amp. The filter caps are shot and I have 4x radial 220uf in my parts box, would they be a suitable replacement?
The Soldono hot rod has them at that value but normally in other amps they are a lot lower typically 50uf
I have attached a schematic of the carlsboro amplifier
-
what's the VDC rating on the 47uF n 220uF caps???
2 - 220uF in series equals 110uF, shouldn't be a problem as long as VDC is close
-
what's the VDC rating on the 47uF n 220uF caps???
2 - 220uF in series equals 110uF, shouldn't be a problem as long as VDC is close
450vdc
They test as 100uf in series
The originals which are actually 68uf not 47uf as in the diagram and are 318vdc
-
I suggest putting a 220K/1W resistor across each of those caps. The resistors will force the voltage to divide evenly across the caps and will also act as bleeder resistors to drain the voltage when you turn the power off.
-
I suggest putting a 220K/1W resistor across each of those caps. The resistors will force the voltage to divide evenly across the caps and will also act as bleeder resistors to drain the voltage when you turn the power off.
Will do
Thank you
-
Wrong post
Please delete
Franco
-
I'm in the process of restoring and modifying a carlsbro 60 pa reverb (tube) for use as a bass or guitar amp. The filter caps are shot and I have 4x radial 220uf in my parts box, would they be a suitable replacement?
Changing from 47µF to 220µF will raise the supply voltage somewhat (though mostly noticeable when blasting loud), and the feel will be stiffer (again, most obvious when playing near max output power).
As long as you're happy with the final result, it should be fine.