[Jazz1]

Hello, I popped for "HiFi" today and was wondering how best to get the best output from a Late 2015 iMac either via optical or USB. I'm using optical right now. I went into Audio Midi and cranked it up to 2 Channel 32-bit 96.0 kHZ which seems to be the "highest" scroll down selection.

I have to admit I understand very little about output sampling rates, and of course my trusty old DAC as well as my Late 2015 iMac could be limiting. BTW I'm using an old PCHA GCHA amp. It does sound good on my Sennheiser HD-650. I've yet to try my Audeze LCD-2, or B&W P9.
Can anyone help this old dude with old dude equipment out

 

[NA Blur]

I think for most applications 16 bit is just fine, but for me I use 24 bit because I can hear a very slight lowering in the noise floor. Any other options I tend to get distortion.

I also use optical too because it removes unwanted noise that USB ports almost always have. Mac's tend to have much cleaner power on their USB ports compared to Windows machines.

What audio files are you playing as in bit depth?

 

[Jazz1]

Hey thanks for such a quick reply! Tidal lists (1411kbps or 16bit / 44.1kHz). I'll give the 24 vs. the 36 a try. It sounds a less strident after my quick try. Thanks!

Audio Midi only on my iMac only allows for 96kHz (which is where the DAC's LED is lite right now). My DAC can go to 192kHz sampling. I don't know if anything I'm using supports anything better. I just want to make sure the extra cost of "High" from Tidal is worth it, and I'm not tweaking settings right.

 

[Roseval]

Audio Midi is gapped at 24 bit / 96 kHz as this is the max supported by the Toslink standard.

Audio files can be 16 or 24 bit.
If you play a 16 bit file on a 24 bit DAC, 8 zero's are attached with of course zero impact on sound quality.
Likewise 24 bit is beneficial when using volume control.
Always set the bit depth to the max your DAC support.

Sample rate is a different thing.
In general things don't improve by upsampling.
Best is to play everything on its native sample rate.
However Apple's implementation is quite good, I would be surprised if you hear any difference between a 44.1 kHz file played at its native sample rate or upsampled by OSX to 96 kHz.