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Were the pots in question used as part of the signal ground? In other words, were the ground lugs on the pots soldered to the back of the pot to make the signal ground connection (volume & mid control)? Was there a ground buss running to the back of any of the pots?
If that was the case, the /resistor/diodes will not work. You would have to just connect everything to chassis ground (like you ended up doing). That combination of parts is intended to isolate Chassis ground from signal ground but it only works if signal ground is completely isolated from chassis ground at all points, like on some PC board amps. The cap, resistor & diodes provide a path for RF frequencies to still go to chassis ground (keep them out of your signal as much as possible). This is basically done to help prevent ground loops (and ground loop hum) when connecting to other equipment that uses a chassis only ground for signal & safety. Some times it is needed, sometimes it isn't. The cap / resistor / diode thing is what you will find most of the time attached to any "ground lift" switch you see on equipment (at least they should be there for the best RF performance).
I have used this successfully on tube amps that I built on PC boards. You just have to run ground wires from the pots back to your signal ground, not to the pot itself. It is OK if the pot is connected to the chassis as long as the pot case is not used as a grounding point. There is no need to isolate the pots. However, you will need to isolate the input jack from the chassis (plastic jack, isolators around a metal jack, etc.) because a metal input jack connects the signal ground directly to the chassis.
If that was the case, the /resistor/diodes will not work. You would have to just connect everything to chassis ground (like you ended up doing). That combination of parts is intended to isolate Chassis ground from signal ground but it only works if signal ground is completely isolated from chassis ground at all points, like on some PC board amps. The cap, resistor & diodes provide a path for RF frequencies to still go to chassis ground (keep them out of your signal as much as possible). This is basically done to help prevent ground loops (and ground loop hum) when connecting to other equipment that uses a chassis only ground for signal & safety. Some times it is needed, sometimes it isn't. The cap / resistor / diode thing is what you will find most of the time attached to any "ground lift" switch you see on equipment (at least they should be there for the best RF performance).
I have used this successfully on tube amps that I built on PC boards. You just have to run ground wires from the pots back to your signal ground, not to the pot itself. It is OK if the pot is connected to the chassis as long as the pot case is not used as a grounding point. There is no need to isolate the pots. However, you will need to isolate the input jack from the chassis (plastic jack, isolators around a metal jack, etc.) because a metal input jack connects the signal ground directly to the chassis.
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