DAC cutting out after 3-4 minutes

[minusnine]

Hi all,

An odd problem has developed in my system after a few weeks of no use - after 3 or 4 minutes playing the sound cuts out although the source is still playing.

System is as follows: mac mini spotify or itunes into ODAC, then into jds atom to either headphones or a minidsp feeding a sub and kef active speakers. The problem occurs with all sources, and in headphones or speakers, and is only resolved when I take the dac out of the system. I’ve tried 3 different usb cables between mac and dac, different usb ports and different audio cables between dac and atom, and the problem remains in all cases.

Does anyone know what the issue might be? The dac is pushing 10 years old but I don’t want to replace it until I definitely know that it (and not some issue that would continue with a new dac) is the problem. Running a cable from the headphone out on the mac mini into the atom resolves the problem but has limited volume.

Ta v much, Andy

 

[gfx_1]

How is the DAC powered? If external try another PSU. I have seen one fail which powered my raspberry pi.

 

[minusnine]

It’s powered by the usb cable, with no option for a separate power connection

 

[gfx_1]

Some monitors have a powered USB hub (dell, hp) maybe route the sound through that just to figure out if it is not the power from the mac.

 

[minusnine]

Thanks, my monitor doesn’t have a powered usb hub but I do use an unpowered usb hub (problem was the same using that or coming directly from the mac mini). I will investigate powered usb hubs...

 

[MRC01]

The problem must be the source pushing the bits to the DAC, or the DAC. For example, maybe the Mac has a software or driver problem that drops the USB connection. Or maybe the DAC has a problem that drops its input.

To determine which, try a different source to push the bits to the DAC. For example, I can drive my DAC from a PC, from my phone, or from a tablet.

Also: if your source were Linux instead of a Mac, I would run "lsusb" when the DAC is working; this will show all USB devices that are plugged in (the ODAC will be one of them). Then run "lsusb" again when it stops working, see if the ODAC has disappeared.

 

[wje]

Are you sure your device isn't going into "sleep" mode?

 

[minusnine]

Thanks both, there will probably be some os x equivalent of that linux program which I will seek out to confirm that the dac as a usb is still working, though it still shows up as working in audio manager.

Likewise, I have never seen any indication of the dac ‘sleeping’ before - I have had problems with other usb devices not waking up with the mac, but that’s not the case here as it works fine for a few minutes before cutting out, then a few minutes later it will work again.

I do wonder if it is a power issue, maybe I have too many usb devices runnign and drawing power, though nothing else has failed. My itunes library is on an external drive powered only by usb, but that’s always been the case and wasn’t a problem before, and the problem persists using spotify to stream.

 

[wje]

Likewise, I have never seen any indication of the dac ‘sleeping’ before - I have had problems with other usb devices not waking up with the mac, but that’s not the case here as it works fine for a few minutes before cutting out, then a few minutes later it will work again.

Oh, I didn't mean the DAC going to sleep, but the source device - check that to see.

 

[minusnine]

Ah, sorry, got you. No, sources are either itunes or spotify and in both cases I can confirm that they are playing even after the sound cuts out.

 

[MRC01]

Is it possible the Mac has dropped the USB connection to the ODAC, even though the music play apps (itunes or spotify) are still running?
Do you have an alternate device, like a different computer, a phone or tablet, that you can use to drive the ODAC, and see if this problem still happens?

 

[ScofieldKid]

Perhaps a try for caffeinate ? see: https://mac-how-to.gadgethacks.com/...-sleep-functions-with-these-commands-0168109/

 

[minusnine]

Is it possible the Mac has dropped the USB connection to the ODAC, even though the music play apps (itunes or spotify) are still running?
Do you have an alternate device, like a different computer, a phone or tablet, that you can use to drive the ODAC, and see if this problem still happens?

Yes, that works - swapping the odac over to my laptop (direct to an onboard usb port) It’s been playing for 10 minutes now without a problem. That focuses the problem to somewhere either on the mac mini or in the power supply to the dac over usb, but the dac seems to be fine.

I will order a powered usb hub - a fair bit cheaper than a new dac!

 

[minusnine]

Perhaps a try for caffeinate ? see: https://mac-how-to.gadgethacks.com/...-sleep-functions-with-these-commands-0168109/

I don’t think that’s the issue in this specific case but I do sometimes have waking issues with usb peripherals so I will check this out, thanks

 

[MRC01]

Great! It sure looks like a software problem; that is, the Mac Mini has some too-aggressive power saving mode kicking in.

 

[ZolaIII]

Try to increase drivers latency (bigger buffer), eventually to boost process priority for it. I don't really use OS X... So can't guide you there.

 

[minusnine]

Well, my powered usb arrived this morning, and... it doesn’t solve the problem. So it must be some sort of software issue. I can’t use the lsusb utility and system report doesn’t tell me anything useful (it still shows the dac even after I’ve unplugged it, and shows the same information on both the mac mini and my mac laptop).

 

[MRC01]

Since it works fine on the laptop, try disabling some of the Mac Mini energy saver features: https://support.apple.com/en-us/HT202824

 

[minusnine]

Yes, though I’d already set the energy settings to as ‘awake’ as possible with no effect.

I just remembered I have a £10 apple usb dongle, it has worked fine for 45 minutes plus so far, although it has a lower voltage output than the odac. I’ll stick with that for a bit.