[appletree]

Hello Recently I bought HA-160 (just the amp without DAC) and I am having some static noise issues when using my desktop PC as a source with only exception being toslink. However usb link to DAC -> HA 160, or onboard sound -> SPDIF -> DAC -> HA 160, or onboard sound -> analog out -> HA 160 (basically any metallic link between PC and HA-160) is causing a harsh (really brutal) ear-piercing static noise and its intensity depends on the headphones.
 
E.g. with Q701 I was trying to listen like that for a while, but had to stop because I started to listen tinnitus like harsh static noise even with headphones off. With HD 595 it's even worse - it's basically listenable just for few seconds (it's so strong it is overpowering the music).
 
Note: I've also tried all the connections on three different desktop PCs in two different  rooms with the same noisy results on all of them. Two of those PCs use high quality PSUs: namely Enermax Modu82+ series and Seasonic X series PSUs.
 
Also note: Everything works OK using a laptop - including DAC over USB, only desktop PCs were affected
 
I purchased the HA 160 under impression that there were some noise / hiss issues but those were resolved long time ago, e.g:
http://www.head-fi.org/t/497166/burson-audio-ha-160-review
"According to Burson, the ground loop was limited to a few computers. To fix this, Burson has used a different transformer."
 
Goal of my question is to determine which of these three cases does my situation fall into:
 
1.) I have a broken unit (Burson's tech support disagrees)
 
2.) I have an old unit (prior to the transformer fix) despite buying it brand new just few days ago (which again should justify RMA)
 
3.) The unit works perfectly according to the updated specs, there is just something profoundly wrong in the way how HA-160 handles desktop PC as a source (three desktop PCs failing in the same way can not be a coincidence)
 
I would therefore like to ask any HA-160 owners if they would be willing to test their HA-160 amps in a desktop PC. It should be pretty simple. Connecting the minijack stereo output of your on-board soundcard directly to the amp and clicking play then trying with both headphone jacks on the amp if any of them is giving you similar symptoms as I described above.
 
Some easy to drive headphones like HD 595 should be the best to test with (but it's immediately apparent even on HD650) You can also try with PC -> USB -> DAC -> HA 160 or similarly over coax link. Just make sure the DAC isn't something fancy like with galvanical isolation of all inputs or something (that's why test with onboard sound -> analog out should be the most straight forward)
 
Any help will be very much appreciated. It would be great if you could also write down if you are using the 120V version or the 230V version - just in case (I am using the 230V here)

 

[dukeskd]

You need a better DAC, that is all I can say.

 

[fabio-fi]

Quote:

You need a better DAC, that is all I can say.

 
This ^
 
A dedicated solution its better in this case. 
 
Check this, 
http://www.head-fi.org/t/620370/how-to-eliminate-computer-noise

 

[appletree]

So what are you suggesting ? That all class A amplifiers hooked to any desktop PC are supposed to suffer with serious noise issues ? And that this is supposed to be a norm ? If so what about the quotation from above:
 
"According to Burson, the ground loop was limited to a few computers. To fix this, Burson has used a different transformer."
 
So if the ground loop is the norm why would Burson Audio need to fix it in the first place ? And - if all class A amplifiers are supposed to suffer with ground loop issues how could the Burson Audio's amps (after the fix) be the only ones where the problem has been completely eliminated (at least that's what the press release suggests). Also: if groud loop was limited to "a few computers" and even those few were fixed (meaning all computers should be without the ground loop issues after that) how is it possible that 3 desktop PCs in my home exhibit all the same ground loop symptoms, right ? Am I the only one who seems some discrepancies here ?
 
I repeat my request: please, is anyone here who can try the HA-160 hooked to a desktop PC according to the first post ? I would very much like to know how it goes.
 
 
And btw I have already tried one USB isolator adapter and one USB hub.
First let me tell you the DACs I've been testing with (both have USB inputs)
 
* Style Audio Ruby 2 DAC with integrated headamp
* E-MU 0404 USB also with integrated headamp
 
 
This is the isolator http://www.firestone-audio.eu/shop/products/allproductslisted/greenkey.php
I have ordered. E-MU doesn't work with it at all (no playback possible) probably due to that USB adapter not supporting USB 2.0  Ruby2 does provide playback, however its headphone output has become noisy (so that adapter acts like exact opposite of isolation for Ruby2's headphone out because without the adapter it's dead silent).
However when Ruby2 is connected via that USB adapter - it's true that the headphone out of HA-160 is much better - probably the same or very close like when Ruby2 is connected via optical. Basically noise-free

I also tried with one random USB3 HUB:
this time E-MU 0404 is not even recognized as a device. Ruby2 seems all fine but when I hit playback after few seconds the playback hangs on some strange USB error

In the end I wasted about 140e on some completely useless gadgets and I still can not do the USB playback right ! Tomorrow I will buy some pure USB2 Hub to see if it makes any difference. (doubt it)
 
Is there some cheap solution which can be ordered in Europe that works 100%? So far these look like a candidates: http://electronicsshop.dk/?id=1038
and https://www.olimex.com/dev/usb-iso.html
 
But will this get rid of ground loop + PC noise ? Will it work with all devices for 100% ?
 
If there is no cheap reliable way of achieving all the goals, then are there some expensive (high-end) solutions that work 100% and can be ordered in Europe ?
 
Unless I can resolve the USB playback issues over the HA-160 in a reliable and consistent way with every possible DAC imaginable the amp is close to useless to me (mostly due to future upgrade limitations).