Mini audio out squeals

jmiddel

macrumors regular
Original poster
Mar 3, 2010
163
34
Land of Enchantment
My Polk iSonic table radio has a squeal in the aux port when attached to the audio out of both my and my wife's Minis, but not when attached to my MBP or my wife's MB. The squeal is also present when I use a USB driven DAC into a preamp from my Mini.
 

nollimac

macrumors 6502
Oct 10, 2013
284
18
Have you tried using line in instead of aux? Are you using an analog cable on the Mini? Seems you're getting a feedback. I would try using an optical out from the Mini and an optical to analog adapter to your iSonic if the aux is analog.
 

jmiddel

macrumors regular
Original poster
Mar 3, 2010
163
34
Land of Enchantment
Have you tried using line in instead of aux? Are you using an analog cable on the Mini? Seems you're getting a feedback. I would try using an optical out from the Mini and an optical to analog adapter to your iSonic if the aux is analog.
Are you saying to use audio input rather than headphone out? How would that work? Also the Mini does not have an optical (toslink) out. I do use USB out via a DAC, but that squeals as well.
 

fa8362

macrumors 65816
Jul 7, 2008
1,341
54
Are you saying to use audio input rather than headphone out? How would that work? Also the Mini does not have an optical (toslink) out. I do use USB out via a DAC, but that squeals as well.
You cannot use line in for output, but I think you already knew that. The Mini does have optical out. The headphone jack is both optical out and analog out.

If USB out also squeals, then you can rule out the both headphone out and USB as the culprits. Your problem is something that affects both, possibly how you have your sound setup. I wish I could be of more help, but I've never had your problem and I've never heard of those symptoms either.
 

DeltaMac

macrumors G3
Jul 30, 2003
9,606
2,352
Delaware
…. the Mini does not have an optical (toslink) out. I do use USB out via a DAC, but that squeals as well.
All intel Mac minis have optical digital out - you would use a toslink mini adapter.
Is that a high-pitched squeal, or a lower pitched hum (like a ground loop)?

A high-pitched squeal makes me imagine feedback through a built-in mic (which the mini doesn't have?)
And, both USB and built-in audio have very little in common that could cause a squeal… "sounds" like something in your hardware, so I think more like a ground loop in your system. (your laptops don't connect directly to house ground (earth), but the minis likely do.)