HQP Issue - Hissing on 22.5m upsampled dsd but not 24m

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1

Hi there

I am getting a strange hiss when I upsample to dsd 22.5 but not on 24.

Machine: Mac mini M1
Hqp settings: DSD, poly sinc gauss hi res ip, amsdm7 512+fs, rate 48 x 512, with adaptive gain on
HQP version: latest version (which I downloaded 2 nights ago)
Other notes: there is a convolution filter in matrix with a gain adjustment of -8db, dac is a Gustard r26. This is a new symptom. This hasnt been an issue before now

Issue: HQP is auto setting the rate as it should based upon the base file rate but I am getting a hiss for the first time on 22.5m but not 24m.

Have I got a rogue setting on that’s causing this or is there something awry with the latest hqp version? Any help would be great.

Thanks

P.S. can also confirm this hiss does not occur when upsampling to PCM 705/768 instead of DSD. The only other change I noticed on my system was a Roon Core / Client update which occurred today.

Screenshot 2023-02-15 at 8.34.26 pm
Screenshot 2023-02-15 at 8.34.26 pm527Ă—1120 79.5 KB

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What happens if you change “Multicore DSP” to greyed out instead of checked?

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Thanks for responding @musicjunkie917 … just tried changing that to greyed out and there’s no change. The hiss appears on 22.5m files but not on 24m. I have also tried changing the buffer back to default, and turned on DoP, and again the hiss is there consistently on the lower file rate on DSD (but not on PCM).

EDIT: it’s also consistent across tracks. I am looking at 5-6 tracks where I haven’t heard this hiss before and now it’s there. The Daft Punk Random Access Memories album is a good example. No hiss on PCM, but a clear hiss on DSD now.

4

Gustard R26? I think your modulator choice is not good for your DAC. Have you tried using ASDM5ECv2 at DSD256? Or DSD512 with just ASDM7?

If it doesn’t happen at 24.576 MHz output rate (strange), you can also use that as fixed rate, by unchecking the “Adaptive output rate”.

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Thanks @jussi_laako for coming back on this - really appreciate your time.

So I tried all those different modulators and there was no change. The 24m sample rate is fine, the 22m sample rate has a v noticeable hiss. When I unchecked the adaptive output rate, there is no hiss. Which is a good compromise (though I understand it’s better to have this checked?).

I am on ASDM7 now at 48x512. I’d be interested to understand more about why you think the Gustard R26 pairs better whether the modulators you listed?

Thanks for your help.

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This is strange, I’d say it’s likely a bug in DAC firmware or similar. If this is R26, you are second person reporting this on the particular DAC model. But earlier I didn’t know that it goes away with the 24.576M rate (48k family clock).

If it works at 24M rate, I would just stick to it. Only negative side increased CPU load because it is heavier to process.

It was just assumption/guess. AMSDM7(EC) is more demanding for the DAC’s analog stages.

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Ok thanks @jussi_laako . Really appreciate your help with this.