Screeching noise heard when trying to play music after powering on Chord M-Scaler that is connected to Roon Nucleus+

Roon Core Machine

Roon Nucleus + running Roon Server Software Version 1.8 (build 1021) on Operating System Version 1.0 (build 227) and Roon Labs Software Version 1.0 (build 12).

Networking Gear & Setup Details

No Network Gear Involve - Roon Nucleus+ is connected to Chord M Scaler via USB.

Connected Audio Devices

Chord Electronic M Scaler connect to Roon Nucleus+ via USB.
Chord Dave DAC connected to M Scaler via dual BMC cables.

Number of Tracks in Library

6,500 Tracks

Description of Issue


Powering up my M Scaler after a power failure or it has been powered off, a high pitch screeching noise, that faintly sounds like the music, is heard mostly through the system’s left channel. This issue has happened almost every time the power is turned on to the M Scaler. After much trial and error doing things like power on & off various components, I have found most reliable solution is to pause/stop the playback of the song/music and restart the song/music.

Initially I thought the issue was between the M Scaler and DAVE DAC. I have been working with Chord Electronics support and they suspect there is a USB synchronization between the Nucleus+ and the M Scaler. They suggested setting the “playback delay” to 1,500 ms to see if it would resolve the issue. I couldn’t find a Roon parameter named “playback delay” but did find “resync delay” and have set it to 1 & 1/2 seconds. It didn’t resolve this issue (Note that this change did resolve another issue of some songs when played starting playing a second on so into the song.)

Hoping that you might have some insights as to what is happening and possible solution.

Thank you for your help,

Try connecting it to a different computer running Roon as an endpoint and see if the behavior is the same or different.

I experience the same problem.

Similar Set-Up
Roon Nucleus + running Roon Server Software Version 1.8 (build 1105) on Operating System Version 1.0 (build 227) and Roon Labs Software Version 1.0 (build 12)

My Previous Setup Details

Roon Nucleus → To Chord M Scaler via USB, To Chord Dave DAC via dual BNC cables

To fix the high pitch screeching noise, I would do the same, pause the song playing / find a different music resolution, play, play, pause, in no particular order, and then it would play correctly. I agree, this would also always happen when I would power up the M-Scaler and Dave. During power cycles, it would happen more often than not happen.

I added this new chain and have not had the issue yet, only tested for 2 days, but so far, so good. Pulled all BNC cables and reconnected them. Added new chain of hardware below.

Roon Nucleus is connected to SRC-DX via USB, Chord M Scaler is connected SRC-DX via Dual BNC Cable, Chord Dave is connected via Dual BNC.

Peter & Tom - thank you both for your replies and sharing your insights.

FYI - Cord’s belief is that M Scaler’s galvanic isolation on the USB input is causing the Nucleus to not “lock in” correctly sometimes when the components are initially connected.

As suggested adding a bridge or similar between the components or using a different hardware as the Roon server can solve the problem.

So adding another component (minimizing the components between source & music is the goal - right) OR changing my server both bothers me. Hoping that there may be another solution.

I have had exactly this problem except it happened when the output of my Lumin U2 mini was fed directly to my Dave via USB. The Lumin/Dave combination was unresponsive to volume control (already configured in the Lumin app & Roon) I thought it would blow up my speakers but i digress.
The problem isn’t specifically related to the Rock, with the Core-Lumin-Mscaler-Dave configuration all is fine.