DAC drops out when Furnace starts or stops. HELP


Every time my furnace or water heater (gas, power vented) kicks on or off my DAC drops out momentarily. My audio system, furnace and water heater are all on separate dedicated ac lines. My AC panel was updated to a 200 amp service some years back.
I checked all connections from the panel to each device and internally checked all electrical connections in the furnace and water heater, verifying proper hot, neutral and ground.
I checked and tightened all wires in the service entrance panel.
Has this happened to anyone else? If so what did you do to correct it?
Any help will be appreciated.
jadedavid
FYI, I have found no correlation between length of USB cable (1m vs. 1.5m) and performance across brands. You are not assured superior quality/performance from a supposedly ideal 1.5m USB versus another brand 1m. It is also relatively easy to find a 2m USB which will outperform any given 1m or 1.5m alternate brand.

I have a few times found that 1m sounded better of the same brand than 1.5. So, you can say I'm not a believer in the idea that 1.5 is somehow magical for sound quality of USB.
Douglas_schroeder,

I use a 2 meter digital coax cable myself. I don't think anyone here said a 1.5M was the magic length.

I think Al, (Almarg), and Kijanki offered a more technical reasoning why the digital cable made the difference and the fact that Jadedavid solved his dropout problem using a different digital cable tells others that are experiencing dropouts caused by the switching on or off of an AC mains load/s it might save them a lot of time to just change out the digital cable instead of spending maybe hours looking for an AC mains problem that may not be their problem at all. It might just be the digital cable. In the end that's all that matters.
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Jea48, Yes, I understand the flow of the conversation.

I was simply following up on Al's side comment about cable length. i.e. If someone has a choice between a 1.5m and 2m USB if possible one should try them, as opposed to thinking that the theorized ideal length cable would automatically be superior. I do, however, favor a shorter USB when I can obtain it.

I also have seen one or two instances in which a particular USB cable worked with some gear and not others. So, it is wise when experiencing a snafu with digital to consider that the USB cable may be incompatible with a particular component.
Doug, I should clarify my earlier comments about digital cable length by adding that they only pertain to electrical (non-optical) S/PDIF and AES/EBU cables. My comments don't apply to USB cables, in part because the risetimes and falltimes of USB signals are vastly different than those of S/PDIF and AES/EBU signals. As I had mentioned, and as further explained in the paper I linked to, signal risetimes and falltimes are key variables affecting what length will be optimal.

Also, I'll add that if a very short length is practicable, such as perhaps 8 inches or so, that can be expected to often be as good or better a choice for S/PDIF and AES/EBU than 1.5 or 2 meters. It is the intermediate lengths, such as 1 meter, which (depending on a complex and essentially unpredictable set of component-dependent variables), stand a somewhat lesser chance of being optimal than those other choices.

Regards,
-- Al
Amazing I had the same problem with my old dac and cd player I never found out what the problem was My new set up does not do it ??? Good Luck.