Static in USB (but it disappears with Airplay"


A couple of days ago I sent an email to PS Audio with this question. Maybe I’m old-school, but somehow I think that having paid several thousand dollars for one of their products, I should have gotten a response by now. Maybe not solve the problem immediately, but at least acknowledge they’ve received it and are working on it. But, nada.

Thought I’d try here. Here’s my issue:

(BTW: I’ve already talked to Jesus at Sonore about this, he responded quickly, as he has to most any question or issue I’ve had. He’s puzzled as well about what might be going on. Also, BTW, I bought the orbiter because the Bridge is basically worthless, which any quick look through these forums will confirm. Sorry, just in a bad mood about this.)

Just upgraded my PW DAC MK II to the DirectStream, using the upgrade kit. I’ve loaded the latest firmware (indeed, it wouldn’t work at all with firmware that came with the upgrade kit) I’m using a SonicOrbiter connected via the USB input to access music on my hard drive. I also have it connected via optical output to an old Yamaha Musicast, primarily to play in another zone in the house (my wife’s space).

In any event, I’ve got background static when I play through the USB input. The optical connection plays fine. I’ve changed the USB cable, but it doesn’t make any difference. These are standard USB cables, which worked fine with the MKII. Now, here’s the really odd thing. The Orbiter’s software allows we to choose various playback options, one of which is Airplay. If I select Airplay to use Audirvana Plus 2.O to playback music, the static goes away. If I go back and select squeezelite, to use Logitech Media Server, the static returns. I find this odd because regardless of whether I’m using Airplay or LMS, the signal is still routed through the USB input (I think, at least if I disconnect the USB while Airplay is playing, sound stops).

Also, btw, and somewhat less importantly, I went to register the upgrade on your site, but I can’t find a serial number anywhere. I of course have the sales slip, but nowhere on the packaging or the receipt do I see a serial number.

Anyway, as you can imagine, the static is more than a little annoying, especially for a not inexpensive upgrade. Any thoughts as to what’s going on?


A very odd problem. My guess the issue is software/player based and is unrelated to the DS, but I do not have any specific suggestions.

Do you have other means of testing the DS’ USB input?


How else could i test it? Give that this was never an issue with the MK II, I have to think it’s a hardware issue, unless there is some setting in the player that is not affected by the MKII but is by the DirectStream. What that could possibly be, I have no idea.

soyka0120 said How else could i test it?
With any other player which outputs USB, such as any laptop.

soyka0120 said How else could i test it? Give that this was never an issue with the MK II, I have to think it's a hardware issue, unless there is some setting in the player that is not affected by the MKII but is by the DirectStream. What that could possibly be, I have no idea.
I don't know the software/players you are using so this is speculation:

Buffer settings in the players come to mind.

Also a difference in the USB between the MKII and the DS is the maximum sampling rate. In the original software shipped with the DS the DS handled double rate DoP (which is DSD wrapped in 352.8kHz PCM) but it didn’t handle 352.8kHz PCM. The Mac defaulted to upsampling everything to the maximum sample rate supported by the DAC and hence the MAC and the DS didn’t get along until the Mac was configured to only upsample to, say, 176.4kHz or 192kHz. The next release of the DS software supported PCM at 352.8kHz and this was no longer a problem. But there’s still the chance that your player can play at 176.4kHz or 192kHz for the MKII but doesn’t handle 352.8kHz for the DS without some glitches. This seems consistent with your reported experience.


No static when I play off my laptop.

The player software is Logitech Media Server. I can’t for the life of me see any setting that I could change to correct this. But if the USB works off my laptop as well Airplay, that would seem to indicate the issue isn’t with the Direcstream DAC, I would think.


Don’t see any setting on LMS for unsampling rates. I’ll have to investigate further. Thanks. It’s starting to make sense.

Sometimes I get nostalgic for the days when the only technical thing you had to worry about was balancing your tone arm right.




I am sorry no one got back to your email request. Where did you send that to? We try and get back to people within 24 hours.

The serial number is located on the rear of the unit on a sticker. You can also pick up the phone and call us and we’ll be happy to help.

Problems with USB connection are likely settings in the program feeding the USB, as Ted brought up. You can easily test this by connecting to a Windows or Mac based computer instead to verify it’s running properly. If a Mac, you need only configure the sound settings to be at a sample rate of your choice, like 176kHz. If Windows, make sure you download the USB driver from our download page.

And, again, feel free to call us for help.


I sent an email to a person I’d consulted with before for tech help (don’t want to say the name here) and when I didn’t hear from him, I used the general contact form on the site. 24 hours did go by in both cases. I didn’t see a number on the sticker, but maybe there’s some other sticker. Ted must be right, I can play from my laptop fine. The problem is evidently with Logitech Media Server, though as of yet don’t see where I can set the sampling rate (though, perhaps like the sticker, it’s staring me in the face). ’




Note on this photo on the left side of DS right next to the master power switch? It says “Serial#”. That’s where your serial number sticker should be.


Right, unbelievably stupid on my part. I have an explanation, but it’s too lame and I won’t bore you. When I get the LMS thing sorted out I’ll post it in case someone else is having the same issues.


coolGee, you’re just like me. Sometimes I amaze myself. Glad we could help. It really isn’t that obvious when you see the two stickers. You’re not the first to have completely missed them.

soyka0120 said Right, unbelievably stupid on my part.
Been there. Have the T-shirt.

Please let us know when you get things sorted out and how.


We have all had out “doh!” moments. They seem to be occurring more frequently rather than less. Not that I’m getting old and forgetful or anything.


I’ve had a Sonic Orbiter for ~2 months now and had the same static issue going USB into my PWD MKII, but strangely only with LMS. I also wrote Jesus and searched the Audio Circle forums. What worked for me is to reduce the buffer size from default (forget what it was) to 200. The units are milliseconds, so this equates to 1/5 of a second buffer. Maybe the Oribiter has enough memory to buffer 200ms worth of data, but not 2s worth.

So the static is gone and I should play with this value some more, but it begs the question. Just because I eliminated the static (at least beyond my threshold), are the bits being delivered perfectly to the DAC? This has me worried. Is 150 or 250 a better setting? I’m wondering how the DS measures bit perfect. I’m about to send in my PWD for the upgrade.



The DS bit perfect test requires that all 24 bits follow a pattern without missing a bit for a period of 2 seconds or more. That pattern contains a few PRNGs and slowly tests the top bits to avoid sending loud noise to a system that wasn’t muted. In particular the low 16 bits are tested thoroughly.

Buffer sizes are quite system specific. To smooth out other hiccups I always try the biggest buffers that work. If you were doing audio mastering, were syncing to video, etc. you might want smaller buffers to lower the latency. Also extremely large buffers may require a big burst of disk reads on a new track or seeking. Still I use a 16 second buffer in foobar2000. :)


Thanks to Jesus R. I am now playing distortion free through the Sonic Orbiter via USB with the following settings:

[Image Can Not Be Found]


Ok, evidently I can’t copy and paste an image and it doesn’t like my file extension, so anyway, here are the Squeezelite settings that eliminate the static distortion when playing through the USB input:

Buffer size: 1764

Period count: 441

Sample format: auto


Glad you got it sorted… now just run the snot out of the DS for about 500 hours… Since you’re using LMS just put it on a radio station or Pandora and you’ll be good to go.

And FWIW if you’re pulling your music off a NAS you might want to try using the optional DLNA setting. Or if using a PC try Jriver… I tried LMS and I wasn’t particularly happy with the SQ… it was ok but a bit coarse compared to Jriver or Minimserver…YMMV

Also the Serial Number for the Upgrade Kit ought to be on the Box the Kit came in…IIRC it’s on the same sticker as the Sku…