T
Thomas Droessler
Guest
My existing Fosi volume pot crackling and scratchy:
 If any of your equipment has this problem.There\'s a wiper in sealed pots
that gets a build-up of oxidation over time. Exorcising it will clean the oxidation off.
0. Turn the amp off.
1. Remove the volume knob .
2. While tapping the top of the unit on a table,
2. Rotate stem  \"very \" fast 10-15 times.
(use rubber pliers handle against the stem )
Also do the treble, base and other pots.
--- Fixed it perfectly---.
3. Didn\'t do yet:
    After doing the above.
    Use a clear hose on the stem to seal it.
   Apply 5/6 drops of alcohol into the hose.
    Exorcise the switch.
   Watch the fill line for absorption.
    Keep exorcising 15 times.
   Let the unit set for an hour to dissipate the alcohol.
     Â
If the volume pot is sealed, it shouldn\'t have any residue, debris, or oxidization on the resistive element or wiper. If too much power went through the part it might have charred the element and a replacement is in order. Sometimes a DC shift can occur with the adjustment of a control and this can result in a brushing sort of sound which might lead you to believe the control was dirty.
FOSI huge troubleshooting site:
https://fosiaudioshop.com/pages/faq
 If any of your equipment has this problem.There\'s a wiper in sealed pots
that gets a build-up of oxidation over time. Exorcising it will clean the oxidation off.
0. Turn the amp off.
1. Remove the volume knob .
2. While tapping the top of the unit on a table,
2. Rotate stem  \"very \" fast 10-15 times.
(use rubber pliers handle against the stem )
Also do the treble, base and other pots.
--- Fixed it perfectly---.
3. Didn\'t do yet:
    After doing the above.
    Use a clear hose on the stem to seal it.
   Apply 5/6 drops of alcohol into the hose.
    Exorcise the switch.
   Watch the fill line for absorption.
    Keep exorcising 15 times.
   Let the unit set for an hour to dissipate the alcohol.
     Â
If the volume pot is sealed, it shouldn\'t have any residue, debris, or oxidization on the resistive element or wiper. If too much power went through the part it might have charred the element and a replacement is in order. Sometimes a DC shift can occur with the adjustment of a control and this can result in a brushing sort of sound which might lead you to believe the control was dirty.
FOSI huge troubleshooting site:
https://fosiaudioshop.com/pages/faq