[Randy Myers]

I am having a small problem with my DAC-10H.  I have a few download albums that were directly recorded in DSD 2.8 (DSD64).  There are certain sections in the albums where I get clipping, a static sound that appears to be coming from the software or probably from the drivers.  It has no bearing on the volume level that I am listening to.  The albums I am experiencing this issue with are renowned for their sound quality and perfect sound reproduction, again recorded directly live to DSD.

Not all DSD files show this issue, however a few do consistently.  I have been in communication with the artist and he has gone as far as sending me his original master files to make sure it is not the files themselves.  He also has had a few friends reviewing the software settings to make sure that I have everything set up correctly.

I am using Roon on a dedicated computer set up as a Roon headless server.  I am also using a Surface Pro 3 as my Roon controller.  I have reviewed and verified all settings within Roon.  The gentleman actually had a friend send screen shots from his setup to make sure that Roon is setup correctly for the best DSD playback. 

Other DACs don't appear to have this clipping issue.  Both my previous DAC (using the ESS 9018 chip set also), and the various ones that he and a few friends verified on.  It almost appears to be either a driver or hardware issue that is causing this.

Has anyone else noticed these issues?  Does anyone have any suggestions?  Is there any updated drivers available, or maybe a setting in the drivers that I am missing?  Any assistance would be greatly appreciated.  Thank you in advance for any help that anyone may be able to give.

I am using the latest drivers available on NuPrime's web site.

One other thing. I have not noticed any issue at all playing PCM/Flac files on the DAC-10H.

[Phil A]

I had a problem playing a couple of SACDs many moons ago on a Bryston SP1.7 with a couple of things that were recorded at low levels and when played back at normal listening volume they would show signs of clipping.  It was the (non-THX - where the specs would limit the output) output of the volume from the preamp going out to the amp.  So if one is using the volume control that is one possibility.  There was no mention of the specific DSD files or the download source (so if someone has those DSD files they can play them to see if they have a problem).

[Randy Myers]

These were originally from Acoustic Sounds.  The artist sent me his original master files for one of the albums to make sure it was not corrupt files.  On the spectrum display on the bottom of Roon his albums appear to be a little higher than the other 100 or so DSD download albums I have.  They are all originally recorded directly to DSD with no editing what so ever. 

It does not matter how loud I listen so very sure the amplifier or headphone amplifier is not being over loaded. 

Was checking out all of the settings in Roon and he had a couple friends also looking at it.  None had any issues and no clipping distortion on their end, but they had a variety of different DACs.  This lead me to think maybe the NuPrime drivers??? 

Obviously I am am not sure on this so is why I was hoping someone may have a suggestion that might work ...

[Randy Myers]

As another test I reinstalled JRiver.  It had the exact same issue.  It almost sounds like a driver issue???  I am using the latest NuPrime drivers...

[Phil A]

Don't know - which artist?  Have not tried many DSD downloads yet (just got 5 SACDs in the mail from Acoustic Sounds today and will convert them to DSD files).  I downloaded some, including a couple of double DSD and a DXD from https://justlisten.nativedsd.com/  and have not noticed issues.

[Randy Myers]

In the last 8 months I have purchased 50 SACD (however they don't go through the NuPrime DAC because I don't rip SACDs).  I have also purchased over a hundred DSD download albums.  These vary from DSD64, DSD128 and two are DSD256.

[Phil A]

Don't know if any of the below helps at all:

https://community.roonlabs.com/t/my-dac-supports-dsd-so-why-is-roon-converting-to-pcm/1657/3

http://www.psaudio.com/forum/dsd-1/pure-dsd/

http://fiio.me/forum.php?mod=viewthread&tid=41343

[smk]

Haven't heard "clipping" in quite some time. The last time I heard similar to your problem was when I had a plastic fiber TOSLINK cable connected to DAC with repeater going to audio preamplifier from Mac computer. Jason Stoddard (Schitt) said problem problem might be repeater not having enough "bandwidth." Bought a correct-length glass fiber TOSLINK cable to bypass repeater & haven't experienced static since. Please post your findings.

[Randy Myers]

So far I cannot determine exact what is causing it.  I am using good solid decent cables, Wireworld USB, Wireworld and Richard Gray power cables, Kimber Kable speaker wires, etc.  I am using Roon, however I re-installed JRiver just to make sure it is not the software or settings.

I am using NuPrime's latest drivers, but as a test i uninstalled these and installed the XP drivers.  The system worked fine, but the issue was still there.  I installed the up to date drivers again. 

Still trying to think of other thigs to try.

[smk]

Sounds like you're using seriously good cables. With my experience being TOSLINK only, I'm stumped.

[Randy Myers]

I even just installed the NuPrime drivers on my laptop and hooked it up to the USB instead of my music server.  It had the same issues.  Again with a very limited number of files,. but those that push the boundaries of  what DSD can do.  These files also go right up to the 0db max threshold... as per the artist, exactly what Gus the producer of the DSD recording was trying to do.

It almost seems like the NuPrime has more issues with DSD but performs fantastic with PCM.

[Randy Myers]

Ok, I just remembered that my Marantz SA8005 CD/SACD player has a DAC and can be used with USB input (basically as a separate DAC).  So I loaded the Marantz drivers on the music server computer.  I setup the Marantz "zone" in Roon.  Roon lets you switch "Zones" (Drivers/DACs) very easily.  So I played the files having an issue through the Marantz and they played absolutely perfect.

Therefore I have tried everything, narrowed down everything over the past three days and I am 100% certain that the NuPrime DAC is the cause of the issue.  Not sure why, but these particular files cause the DAC-10H to clip (scratchy distortion) when certain notes hit 0db.  The Artist verified with a friend of his that these point show on his Mytec Brooklyn meters that it hits 0db.  He also said very few selections will go to 0db, but Gus at the Boulder studio set the recording to go exactly to 0db, and never over.

Jason if you are following this would you please jump in with NuPrime's thoughts.

[Randy Myers]

While we don't have the final end resolution as of yet, I just want to express my thanks to Jason and crew at NuPrime.  These guys are amazing and it is obvious to me just how important customers and their positive experiences with NuPrime gear is to them.

Thank you very much for caring about your customers as much as you do.  You guys are fantastic!

[Phil A]

That's one of things about computer audio (I have multiple systems using it) is that one has that hardware/software interface going on and sometimes one cannot predict all the variables.  I'm actually looking in the near future about the potential to get off the Windows platform to at least lessen some of the issues (not that they are the end of the world) that arise from time to time.

[Randy Myers]

Hello Phil,  You do what you feel is best for you.  As a computer guy I doubt I will ever go to an Apple OS based product.  Yes I know that many people use this platform for audio, but a very high percentage of people who are comfortable with computers and technology do not.  My own feelings are I want a system that allows me to do what I want, put files where I want, setup the computer how I want.  Apple's big brother approach makes this very difficult, and this is not to my liking.

Lynx platform may also be a choice, but in my opinion it is currently too limiting.  I believe that Windows 10 Pro is an excellent platform for a music server to be built around.

I have a dedicated PC that was originally purchased from Falcon Northwest.  The machine has the same mother board that several of the dedicated pre-built music servers use, and I have heavily modified it for use as a Roon Headless Server.  It has much higher level components then most of the music servers that are for sale; Intel i7 CPU, 16 GB DDR3 RAM, Gold Standard power supply, liquid cooled, External wi-fi antenna, SSD storage, mounted on a granite base, etc.  I know I could not best this with an Apple OS based system.

By the way, we are 100% sure that the rare issue that I have been working to resolve has nothing what so ever to do with the music server operating system or Roon software (JRiver either for that matter).