Having a problem when HVAC system turns on and cuts my system off!

Hi Bill,

Strange problem indeed, especially given that it wasn’t present for a year or so with essentially the same system.

I don’t think we can say at this point whether the problem is caused by interference from airborne RFI or by effects of the HVAC on the AC power. Or whether what may have changed or degraded relative to when the problem didn’t exist is in the audio system or the HVAC system.

The only suggestions that occur to me at this point would be to perform the following experiments:

1)See if the problem occurs with the iFi reclocker removed from the system.

2)If you have power supplies that can be temporarily used in place of the two 9 volt linear supplies you mentioned, give them a try.

3)If practicable, try to determine if the problem occurs when the volume control on the 2170 is turned all the way down. Perhaps some circuit point in the 2170, or a cable that is connected to it, is picking up airborne RFI when the HVAC system turns on, which is then amplified by the power amp section of the 2170 and in turn inducing a transient at an upstream circuit point.

4)Determine if the problem occurs when the HVAC system turns on for heating purposes, for cooling purposes, for fan only purposes, or for some combination thereof.

Good luck. Best regards,
-- Al

@steakster

I think you are onto something. Please give me some external ground options. I assume the outlet plate screw won’t qualify?

No doubt the issue is linked to the turning on of the HVAC unit as there is a 100% correlation.

@almarg The volume has no impact. HVAC for heating is the cause right now. I think you are right to suggest pulling out one LPS at a time to test.

Thanks guys! 

I had something akin to this happening with my computer feeding USB to my Lampizator Golden Gate DAC, where every time the AC kicked in the music stopped for ~ 5 - 8 seconds, but then it would reestablish connection and continue.  Of course that gap drove me nuts!  Worse yet, it wasn't just my AC, but also my many neighbors' AC systems that triggered this event.  I'm guessing a momentary power line sag occurred from the start up capacitors in the AC systems.

I tried a Topaz isolation transformer on the line, both in normal mode and in balanced mode, and it did not help.  What did solve this problem for me was to try a PS Audio P-10 power regenerator.  This stopped the maddening interruptions that I was suffering, and it actually sounded almost as good as my best power feed set up (Topaz in balanced feeding a very expensive power cord feeding an equally expensive HB Marble power distribution bar).  Now I have enjoyed continuous play for 18 months and counting.  It might be worth a try in your system (and might give your system's sound quality a boost, too).