Okto dac8pro native DSD multichannel playback issues

[jrobbins50]

I posted over at the Roon forum on this issue, as well. I’ve built out Chris Connaker’s new CAPS20 server with the anticipation that I would be able to use it with USB out to the Okto DAC via the Okto-supplied DIYNHK driver and play multichannel files natively up to DSD128 with convolution applied. Frankly, the native DSF multichannel files that I have are DSD64, so not even as demanding. But, all I get is stuttering and Roon loses control after 15-17 seconds of playback. In particular, I hope that @Kal Rubinson will weigh on on what he’s been able to do with the Okto using his Pink Faun server, which would be closest to the CAPS20. And I’ll take any other advice, of course!  Thanks. JCR 

[Kal Rubinson]

1 hour ago, jrobbins50 said:

@Kal Rubinson will weigh on on what he’s been able to do with the Okto using his Pink Faun server, which would be closest to the CAPS20. And I’ll take any other advice, of course!  

Roon is an issue, as ever, but I got the most reliable playback out of the PF/Roon/Linux by using HQPlayer imbedded as the output.  Running it on Win10, with Roon or JRMC was good, too, as long as the PF was not asked to do much additional processing/DSP and, as usual, Roon always imposed more overhead.  Remember, downsampling a DSD256 file or upsampling DSD64 file to DSD128 is work.  

 

Can you post your live Roon signal path with processing speed?  What CPU do you have?

[jrobbins50]

@Kal Rubinson, it’s an i9-10900K processor, 32Gb of RAM, and an EVGA GeForce RRax 2080 Ti XC GPU for HQP CUDA offloading.  With my old i7-4790 processor and 16Gb of RAM, I could do DSD128 with convolution on HQP but not DSD256. Now, I can do that, but not DSD512 in HQP without stuttering.  It never gets taxed so I don’t understand the issue. Chris Connaker thought it was the 966K of taps in Roon, but that’s offloaded to the GPU anyway and disengaging convolution still doesn’t solve the problem. 
 

On the Okto side, with the old processor, it worked fine for 8-channel at 24/192. No better with this huge machine. A big disappointment for the dollars invested in the new server, so far. 
 

Roon path included. You can see why it dies with such poor processing in Roon. JCR 

[Kal Rubinson]

This surprising and a bit depressing.  Can you delete the convolution and see what effect that has?.  Perhaps off-loading to the GPU isn't happening.  Should we not see HQP in the signal path?  

 

 

[jrobbins50]

Ah, @Kal Rubinson, right now, I am NOT using HQP for the Okto. Maybe I should try that. But, during the 17 or so seconds that Roon is playing native MCH DSD64 out through Roon, the CPU doesn’t go past 21%. It’s sleeping and yet stuttering. 
 

I should also try MC26. 
 

I am using HQP for its virtual audio input so as to take my phono preamp output through the Benchmark ADC1 converter and run its digital output through HQP and convolution. This is for real-time vinyl playback and is outside of Roon. I can scale there from 32/192 out of the Benchmark to 44.1x256 with ASDMEC7 in HQP — but can’t do DSD512, which my little Pro-Ject PreBox S2 can handle. I have heard that “magic” happens at DSD512 and that’s what I’m trying to achieve.  

Yes, a $4,000 server that isn’t doing much different than my now five year old $1,600 server is indeed as you say both surprising and a bit depressing. JCR 

[Kal Rubinson]

Do you have any idea about or control of CPU priorities and core use?

[jrobbins50]

@Kal Rubinson, resource manager tells me that when the Okto runs, I get to about 26% CPU usage. msconfig has an advanced setting with respect to cores (10 of them on my processor). From what I read, so long as the box there is not checked, the operating system automatically uses the number of cores necessary for the task. But, I set it manually for all 10, rebooted and tried. No difference. Sigh.  
 

I can’t get 2XDSD native set in DSP Studio in MC26 other than for 2 channels (the ability to select source number of channels or 7.1 isn’t available when I pick 2XDSD), and even that doesn’t work with the Okto driver. What settings are you using in MC26 for your Okto? JCR 

[Kal Rubinson]

I never use 2XDSD.

[jrobbins50]

@Kal Rubinson, how then are you running the Okto for MCH in Roon?  JCR 

[Kal Rubinson]

I choose never to upsample because I have never been convinced of the need to do so.  I play all my at native rate.

 

One exception was with the PinkFaun/Roon and the Dac8 PRO when I used HQP to play all DSD at DSD128.

[jrobbins50]

Ok, @Kal Rubinson.  I am now happy to report great progress. For MCH with the Okto, I am now using HQP desktop in my new server through a microRendu and all tracks upscale to native DSD128.  In addition, I have worked together with Bernt from Audiolense and Jussi from HQP to successfully map (manually, at this point) AL MCH convolution filters into the HQP convolution pipeline matrix. So, the system path now runs ASDM7 with convolution (still can’t do ASDM7EC in MCH at native DSD128, though, as Jussi says can’t be done in MCH with any processor on the market today).  Impressive sounding. 

When do you expect (if ever) that Stereophile will publish your review of the Okto DAC?

 

On the 2-channel digitized vinyl side, I have DS7 running at DSD512 using HQP running through an RPI3. Next up there is to use AL’s RIAA functionality to imbed directly into the convolution filters and take a phono preamp entirely out of the system. JCR