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USB powered DACs

Discussion in 'Sound City' started by davidmt83, May 7, 2018.

  1. davidmt83

    Hitman

    Joined: Nov 26, 2012

    Posts: 782

    Word of warning, I wouldn't bother getting a USB powered DAC as my experience of them is you'll hear a very annoying computer electrical interference noise coming through your speakers.

    This post is just a heads up for any potential buyers. Either get a mains powered DAC or be prepared to troubleshoot this issue. I've got no idea why they're sold as you can clearly hear the noise when music is playing on a medium to low volume.
     
  2. Rroff

    Man of Honour

    Joined: Oct 13, 2006

    Posts: 57,424

    Usually due to a ground loop or similar - its relatively easy to isolate them and not that expensive but I guess its one way of saving cost :(
     
  3. neil_g

    Sgarrista

    Joined: Dec 9, 2007

    Posts: 9,603

    Location: South Hampshire

    Usually a pc issue rather than the dac.

    I used an optical dac to solve my bad inference issues coming from 3.5mm out to my monitors.
     
  4. davidmt83

    Hitman

    Joined: Nov 26, 2012

    Posts: 782

    Yeah agreed, it most probably is a PC issue but the result of the DAC being USB powered means it exhibits the results. My understanding is a mains powered DAC wouldn't exhibit the same results.

    As it's such a common issue I feel like whatever combination of plugs / power strips to resolve ground loops should be clearly explained and advised upon in the user manual. As it is it's not fit for purpose.
     
  5. rids57

    Soldato

    Joined: Jul 25, 2012

    Posts: 5,877

    Location: Ankh Morpork

    I got some EMI coming through the USB with my mk1 Schiit Modi but it was only noticeable when not playing music. My Modi Multibit, being mains powered is totally silent.
     
  6. davidmt83

    Hitman

    Joined: Nov 26, 2012

    Posts: 782

    So speakers and amp on one power strip = electrical noise. Moving the PC PSU onto the same power strip = same electrical noise. I'm guessing I'm missing what the correct combination is.

    Cheers, yeah it's so frustrating when you can hear it when playing music relatively quietly or when it's classical or something else similar.
     
  7. Rroff

    Man of Honour

    Joined: Oct 13, 2006

    Posts: 57,424

  8. rids57

    Soldato

    Joined: Jul 25, 2012

    Posts: 5,877

    Location: Ankh Morpork

    looks like the same sort of thing that ifi use in their USB powered DACs and those are utterly silent
     
  9. davidmt83

    Hitman

    Joined: Nov 26, 2012

    Posts: 782

    I should add that using a laptop (both on battery and mains) did resolve the noise issues, whether this is the case just for me, or more in general I couldn't say.
     
  10. rids57

    Soldato

    Joined: Jul 25, 2012

    Posts: 5,877

    Location: Ankh Morpork

    it was the GPU causing the noise in my case, as soon as I started gaming I could hear the EMI ramping up along with the GPU cooling fans. I get zero noise through the Modi Multibit and oddly enough, my Asus STX isn't affected either.
     
  11. Rroff

    Man of Honour

    Joined: Oct 13, 2006

    Posts: 57,424

    I have to be a bit careful on my setup to keep the soundcard away from where the NIC hardware is on the motherboard - the AE-5 seems fairly well isolated against it but the other soundcards I've used in this system like my X-Fi were much more susceptible to it. I've not really noticed any issues with EMI from the GPU though.
     
  12. Swifty55

    Soldato

    Joined: Feb 21, 2006

    Posts: 5,350

    Location: Home

    I’m getting coil whine from my GPU now and it transfers to my sound card and through my headphones. Very annoying.

    I’ve bought a Creative Soundblaster Omni for £20 off of a friend which I hope will solved my issue.

    I know it’s not a high grade product etc for you audiophiles but as long as it does the job I’ll be happy!
     
  13. danza

    Capodecina

    Joined: Mar 28, 2005

    Posts: 13,563

    Location: Drunken badger punching

    I've got a Meridian Director running off my PC with no issue at all. It sounds just the same powered with its dedicated PSU. No whine, no white noise, nothing.
     
  14. Mik3

    Mobster

    Joined: Oct 18, 2002

    Posts: 2,796

    Location: Andromeda

    You could rig these up with just a USB extension cable. Cut into the cable, cut both the positive and negative wires, on the female side that connects to the USB DAC connect the positive and negative to a 1A 5v phone charger and leave the signal wires intact. Its a simple solution with items you probably already have.
     
  15. deFiniLoGy

    Mobster

    Joined: Mar 7, 2013

    Posts: 2,732

    Location: NE Lincolnshire

    Schiit Wyrd or Schiit Etir?

    I've used both and Etir is the one I'm sticking with atm.