Audio system pop

[jeffjmr]

Struggled to pick the right forum for this as it applies to a couple.

My audio system exhibits a loud pop when virtually anything is cycled on or off in my house. And it is getting progressively worse.

It started out when my AC compressor would start or stop, then slowly progressed to even a low wattage LED light if on the same CB.

All my audio components either have RF line filters on their power cords or are plugged into either a noise filtered UPS or a bucking transformer with a filter. So this sounds like something more related to my mains electrical panel.

Any ideas how to start troubleshooting this issue?

Thanks,
Jeff

[f4eru]

isolate which component of the system is doing this.
check the electrolythics inside for ESR

[bdunham7]

Not to nitpick, but I think your forum choice reflects the wrong path!     But maybe it will work out.

What is the 'audio system' and under what conditions--i.e. what are you listening to--does it happen?

[jeffjmr]

Yamaha V685 used as a preamp only. Dynaco ST-70 driving a pair of Altec Lansing A5X VOTTs.

Matters not what I’m listening to. Happens with no program selected. Preamp on or off. Volume muted or not. All light switches, flat screen TV powered on or off makes the pop. Those are all on the same CB, but the AC compressor is not and it is the worst. So it is the tube amp that is picking it up. I can change receptacles but still the same CB. Going to get a long extension cord so I can be on a different CB but with the AC doing it I don’t expect a difference.

Thanks,
Jeff

[bdunham7]

OK, I assume the Dynaco and the Yamaha amps have two-prong cords?  How is the system grounded--perhaps in more than one place?  What other components are connected in any way to the system (even the powered off ones) and is there a cable (Cable TV, internet or antenna) going to the system at any point?

If you think the pop noise is originating in the amplifier (whether it is at fault or not) then try disconnecting everything going to the amplifier except the speaker cables and power cord.  And then try flipping the power cord and try to replicate the noise either way.

[NiHaoMike]

Have you tried connecting the speakers to the integrated amplifier in the Yamaha? The low level analog output is more likely than not just for a cheap way to add external amplifiers for audio in other rooms and it wouldn't take much noise pickup to really degrade the signal. Modern digital amplifiers are very good.

For reference, truly high end analog audio is differential and there's a good reason for it.