Hello there, i'm new to this forum so please let me know kindly if I do something wrong/disattend this forum's rules etc..
So i ran into this old amplifier looking for junk in a basement and i took it. It still worked pretty well except for a quite loud background noise and some annoying problem with ne normal volume potentiometer (or at least so i thought initially)
This is the circuit schematics of the device I'm talking about
https://idoc.pub/documents/fender-frontman-15g-15r-guitar-amplifier-schematic-qvnd60wyor4x
So, to reduce the background noise I removed the reverb unit and that seemed to help a little.
About the normal volume potentiometer I ran some tests with my multimeter and it looked like a perfectly fine working logarithmic potentiometer but I still have this problem with volume that quickly escalates from nothing to super loud just by opening it a little bit (let's say 1/10 of the whole ride) I don't know what happens if I turn the knoob even further because the loud noise is already unbearable at that level.
I tried testing some of the capacitors directly linked to the normal volume and the main input part of the circuit but I only have a basic multimeter so although high capacitance capacitor seemed to work fine (by running a "resistance to infinity" test) the small capacitance ones were basically untestable.
Lastly I still have some background noise which at this point i think might depend on some defects on the main input part of the circuit.
Do you guys have any idea how to approach this reparation project?
Thank you in advance for your time
Plato
So i ran into this old amplifier looking for junk in a basement and i took it. It still worked pretty well except for a quite loud background noise and some annoying problem with ne normal volume potentiometer (or at least so i thought initially)
This is the circuit schematics of the device I'm talking about
https://idoc.pub/documents/fender-frontman-15g-15r-guitar-amplifier-schematic-qvnd60wyor4x
So, to reduce the background noise I removed the reverb unit and that seemed to help a little.
About the normal volume potentiometer I ran some tests with my multimeter and it looked like a perfectly fine working logarithmic potentiometer but I still have this problem with volume that quickly escalates from nothing to super loud just by opening it a little bit (let's say 1/10 of the whole ride) I don't know what happens if I turn the knoob even further because the loud noise is already unbearable at that level.
I tried testing some of the capacitors directly linked to the normal volume and the main input part of the circuit but I only have a basic multimeter so although high capacitance capacitor seemed to work fine (by running a "resistance to infinity" test) the small capacitance ones were basically untestable.
Lastly I still have some background noise which at this point i think might depend on some defects on the main input part of the circuit.
Do you guys have any idea how to approach this reparation project?
Thank you in advance for your time
Plato