Minidsp flex USB input sounds worse than optical, why?

[NJ coffee roaster]

I stream Spotify lossless from my MacBook Pro for listening, normally use the optical out of my samsung tv connected to the minidsp for Spotify, as it seems to be totally transparent. When I plug in a USB cable from my MacBook Pro and play the same material, I get significantly less detailed sound, its similar to listening to a lower bitrate compression despite Spotify still being set to lossless.

I cannot for the life of me figure out why this is, I would assume the same digital signal totally unaltered via optical or usb would sound identical. Anyone have any ideas as to what's going on?

 

[JRowland]

Have you configured your Audio MIDI set up to match the USB output to the format you are trying to play? iOS does this automatically but the computers do not.

 

[NJ coffee roaster]

Have you configured your Audio MIDI set up to match the USB output to the format you are trying to play? iOS does this automatically but the computers do not.

Thanks for helping, its currently on 2ch 24 bit 48khz

 

[JRowland]

Thanks for helping, its currently on 2ch 24 bit 48khz

Spotify I think streams lossless the same as Apple at 44.1kHz? Maybe try that just to see if they sound the same then. I'm purely guessing at this point, way out of my wheelhouse.

 

[NJ coffee roaster]

Spotify I think streams lossless the same as Apple at 44.1kHz? Maybe try that just to see if they sound the same then. I'm purely guessing at this point, way out of my wheelhouse.

I tried every setting in the midi output options, no major difference, streaming to the tv via optical still sounds far better, when I would assume the opposite.

 

[LesterHiggins]

I tried every setting in the midi output options, no major difference, streaming to the tv via optical still sounds far better, when I would assume the opposite.

I am not an expert in these matters by any means (IANAEITMBAM?), but my understanding is that USB connections have the potential to carry a lot of electrical noise, especially when connecting directly from a PC's USB port. Mac USB ports, in my experience, aren't reliable connections for audio - my 2024 M4 Mac Mini rear Thunderbolt ports are loose enough to cause the signal to break from typing vibrations, and the front USB-C ports never worked for audio at all, so I wouldn't be surprised if noise is a factor in your USB connection, whereas an optical connection interrupts the electrical signal and replaces it with pewpews. Or you might try a higher quality shielded usb cable and see if that makes a difference.

 

[Ruediger]

I stream Spotify lossless from my MacBook Pro for listening, normally use the optical out of my samsung tv connected to the minidsp for Spotify, as it seems to be totally transparent. When I plug in a USB cable from my MacBook Pro and play the same material, I get significantly less detailed sound, its similar to listening to a lower bitrate compression despite Spotify still being set to lossless.

I cannot for the life of me figure out why this is, I would assume the same digital signal totally unaltered via optical or usb would sound identical. Anyone have any ideas as to what's going on?

Not an Apple guy, but on a PC I would look for filters, optimizations, sound enhancer recommendations.. lots of options can be active.

USB is a data connection. It either is up and has enough bandwidth or you get disconnects/stutter/clear impacts on sound. But not a continous stream of a different flavor.

It's also possible that the music material is not the same. Or a different set up decoder at work, worst case a transcoder (this can change sound quality a lot, especially intransparent defaults).

 

[Paul7777x]

You could try a galvanic isolator. If electrical hash is the problem that should help.

If not then a USB to optical converter will.

They’re about £70 for a good one.

 

[thcdru2k]

I would make sure to level match carefully. No audible difference between USB, toslink, and analog on my Flex