Roon Keeps losing connection from iMac to Topping D50s

I’m using a USB output from my iMac, into a Topping D50s DAC, the to a desktop amp. Roon constantly “loses” its connection to the D50s. No problems finding my Bluesound Node, Sonos, etc. The only solution is to constantly reboot.



Some thoughts from a fellow user:
Don’t let the iMac or DAC turn off or go to sleep.
Try a different USB port.
Maybe try a powered USB hub.
Set the Topping up on a network endpoint and do not use USB

USB can be finicky especially if it thinks the connection has gone down. In this case, as you’ve seen, a reboot is necessary to re-establish connection. Although you might try just plugging and unplugging the DAC and see if that works.


–sleeping inevitable for Mac
–will try alternate USB/hub
Not sure how Topping can be network endpoint; nu ethernet connection on it…
Unplugging DAC --no joy.

Would you consider amphetamine for your Mac, it will stay awake for as long as you set it for?

Yes, maybe that will help. But if I switch to another sound device–eg, listening through safari, the same thing happens. :frowning:

Ah ok, that sounds like a like a “handshake” issue to me; but, I am little more than barely competent! Can you set the Mac’s output to the DAC? Or, do you connect solely through Roon?

My apologies if I am teaching you to suck eggs.

Hello Peter,

Are you using the USB cable to power the DAC?


no–DAC has own power cable

Frankly not sure. Mac seems to be connecting to DAC via USB; you can see it in midi settings

I’m sorry that I can’t be of anymore help. I just checked with my Mac and I can swap programmes/apps and the DAC copes without needing re-setting, but it’s not the same make as yours.

This is what comes with the DAC.

The power cable is the yellow feature connector to USB which obtains its power from a USB source usually on a computer.

This would be suspect for me.

One way to trouble shoot is a Apple Phone charger. It will also power this DAC and it is a highly rated wall wart. NOTE: Check your power rating first - 5V / 1A. If this fixes your issue, then you have a few options.

There are 2 other different ways that I found that are better especially for fidelity. One is an in-expensive Wall Wart made for audio.

This will clean up your power quite a bit especially for the price.

I used this wall wart for a while and then I moved up to a Linear Power Supply from Topping especially made for this DAC. The P50 Linear Power Supply. It has the same dimension and makes for a nice looking stack.

Hope this helps.


I really appreciate the advice.

I have the power plugged into a powered USB hub. the DAC never loses power, even if Mac is off. So not sure this is it.

Instead, Roon “loses” the D50s as an audio source and asks me to select an audio zone. The only way to get it back is to reboot.

FWIW, Roon also “loses” the iMac as a playback source too; same result if I open Roon on my phone. Reboot fixes everything. This is really puzzling.

Hi Peter, I had a few challenges when I used my Mac as my core, so I bought a NUC from a fellow Roonite here on the forum. I have had it operational for a fortnight now and it has been wonderful, it is faster and works without drop outs, maybe something to ponder on?

I used to have similar issue on a Topping E50 DAC. Power is via usb to barrel connector.

If i plugged this cable into back of imac then DAC would get lost on sleep / wake.
Plugging this power cable into a powered usb hub fixed it for me. Assume 5V phone charger will give same effect.

I have DAC connected to imac via usb for Roon in excludise mode and also connect imac via optical for non roon audio needs.

I’m using a nuc as my core; I use the Mac as a “head unit” to play my desktop stereo

Power is plugged into a powered hub. Tell me about this exclusive mode–could that be my problem?

In roon device settings.

Apologies, I hope you can find a fix soon.

It’s not the Mac. I’ve used an Intel iMac and a Mac Mini without a problem with my USB DAC.

But I always turn off the sleep mode


Do you have another USB powered hub to test with?