iMac USB ports noisy?

carbontune

macrumors member
Original poster
Sep 11, 2018
89
17
United Kingdom
Is anyone using a 2017 iMac and playing audio via USB to an external DAC and then onto powered speakers? I have spent a lot of money changing DACs and cables but still get a crackling noise from the speakers. If I plug a Blu-Ray player directly to the speakers via phono cables then the crackling noise is not present. Also, strangely, if I plug headphones into the DAC then I don’t hear the crackling noise either.

Speakers are KRK Rokit 5.

I’ve reduced the noise by using a very high quality USB cable between the iMac and DAC.

The only other thing I could try is another set of speakers but that’s a very expensive option. I’m going to try using the 3.5mm headphone out on the iMac directly connected to the active speakers via a 3.5mm to RCA cable.

As the iMac is just a few weeks old then I could contact Apple and I’m so disappointed as it’s cost me around £3.5K for the iMac and I get very poor audio quality from it, plus Apple has limited the digital audio output to USB only.
 

cbautis2

macrumors 6502a
Aug 17, 2013
728
589
You can just buy the iFi iUSB 3.0 + iFi iGalvanic with Gemini 3.0 cables (for a good measure) if you're in the UK
 

Cayden

macrumors 6502a
Jul 10, 2014
791
385
Utah
Are you using Logic or do the crackling issues occur no matter the source? I’m also having some issues with crackling audio issues through a USB DAC but they only seem to happen when playing from Logic and I’m not sure why
 

carbontune

macrumors member
Original poster
Sep 11, 2018
89
17
United Kingdom
Are you using Logic or do the crackling issues occur no matter the source? I’m also having some issues with crackling audio issues through a USB DAC but they only seem to happen when playing from Logic and I’m not sure why
Setup was iMac USB to a DAC to studio monitors. I tried a couple of DACs with the same results. I tried several USB cables. I tried many analogue cables from the DAC to the speakers, both balanced and unbalanced.

This week I noticed that the speakers made a noise even when the DAC was powered off but had been on and music had been playing. I then plugged headphones directly into the iMac and the sound was fine. Then I tried the headphone output on the DAC and that was fine too. This left just the speakers. So, it may not be the iMac after all.
 
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