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

The Lyngdorf 2170 is made to specifically use the usb input built into it. It is really not a dac as the signal stays in the digital realm right up to the point it hits the output to the speakers. That is not the issue. Also, I have a IFi Micro USB 3 filter/reclocker between the Computer output and Lyngdorf.

It just happened again. The music stopped playing over the speakers even though the song continued to play on the server. Somehow the HVAC is cutting off the signal through my computer - iFi Micro USB 3 - Lyngdorf. These are all connected by two usb cables. This time I simply hit pause and play again to resume the music. So darn strange.

Adding more detail for you all, both the USB output card on my computer server (SOtM) and the iFi Micro USB 3 are powered by 9vdc linear power supplies. I checked both LPSs and they are outputing 9 vdc as they should. Both LPS units are plugged into the BPT conditioner.  Something tells me perhaps they are not happy when the HVAC turns on at times?

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

The HVAC might be causing a ground differential when kicking on.  Try grounding the Lyngdorf chassis to an external ground.

@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! 

Depends on the design of the outlet & outlet box. This theory could be tested by running a ground wire to the plumbing. But, it won’t work if it's PVC. Is there an external ground lug on any of your power conditioners?