Thread: How do I solve this high pitch whining sound?

I'm flummoxed by a noise when connecting a different dac to my system. Set up is: Tisbury Preamp to Winsome Labs T amp (vol at max so it's used like power amp) to some Leema Xero speakers. I was using a Khadas toneboard as a dac and sounded great with no issues. Then swapped it out for SMSL Sanskrit 10th Anniv dac. Once introduced, a high pitched whine appeared through the speakers. I've tried various things to identify the cause so far:

1. Removed pre amp and used Winsome Labs with its own volume control - still whine
2. Changed phono cables and USB cable - still whine
3. Changed SMSL dac for another I have which works perfectly in another system - still whine with different dac.
4. Put Khadas back in and whine disappears
5. If I reduce the maxed out volume on the Winsome Labs Mouse, the whine reduces, but reducing the Tisbury pre volume does not reduce whine
6. Strangely, if i put downward pressure on the Winsome Labs mouse top (quite flimsy top), the whine reduces (but doesn't go away) and if I play with the phonos going into the back of it, the whine changes and reduces in volume.

Can someone help with an explanation and solution? I can't get my head round why both SMSL dacs cause a whine through my speakers which is influenced by putting pressure on the top of my case, yet I've never had a problem like this with any other set up (been quite a few) that I've used the Winsome Labs mouse amp in. Why would both SMSL dacs cause a similar issue through this set up? Hmmmm?

Did you attach the line and neutral side of your power cable on the right side in your equipment?

I don't know whether the DACs are galvanically isolated - had a quick search and couldn't see that. I've not had problems with them in various other set ups, just this one.

Originally Posted by Alkyogre

Did you attach the line and neutral side of your power cable on the right side in your equipment?

I'm not sure what this means. The dac draws power from a USB connection. In fact, there are two usb sockets. I use it as a usb dac connected to my pc so the second usb connection is redundant and not used. Does this affect what you think might be the problem? As mentioned, the whining sound doesn't happen with this dac in other setups.

I don’t know, sorry

Have you tried disconnecting (and reconnecting) various components/subsystems to isolate the problem?

Some of the better power conditioners/distributors (e.g., Shunyata) have features to eliminate noise emanating from components in your system and traveling to other components via their power cords. Maybe something to look into if you haven't already.

Same question, your dac was feeded by the USB, but your amp has a normal power cable. Did you place the cable the right way in your amp with the line and neutral on the right side?

Second what you can try, hook your power cable on another group with a long cable, is it still there?

Third, disconnect everthing one by one, with high amp volume. Is there another piece of equipment disturbing?

Hi Alkyogre, I'm still not sure what you mean regarding the live and neutral on the right side. The power cable can only go in to the amp one way so there is no way to swap live and neutral. I tried various things to isolate the problem in my system - changed amp, dac, cables etc. As mentioned, the problem relates to the amp, and seems to be worsened by the SMSL dac when connected to a live output. I may have misunderstood your suggestions though.