To upsample or not to upsample

Ah well I have started to fiddle around with Roons DSP and started upsampling to PCM 192, which is what my Bifrost AKM DAC requires, so nothing too fancy.
No idea if I am imagining, or if it really is a fact. To me after short testing it sounds better. The word I would use is more air around the instruments and fuller. Using linear filter. It is not night and day, but it really seems to improve things. Which I find pretty fascinating. I had been reading a lot about hqplayer and had been wondering about it, but I guess my hardware would not be powerful enough, whilst the upsampling Roon does at the moment, is easy on my Nuc.
I will keep the setting for now and see if it is an improvement in the long run. From what I heard the biggest improvement were strings in large scale orchestra recordings, sounds like there were a couple of more violinists playing smoother. As I wrote before at the moment I do not completely trust my senses. Yet returning to original with the same music it sound scratchier. So am hooked. Therefore if you have not tried, just play with it a little and see what you prefer. Could well be I am a convert now :wink:

I’ve been experimenting lately with upsampling, as well as with HQPlayer filters, REW analysis, and convolution.

Tentative conclusions:
upsampling per se does not seem to offer any significant improvement;
HQPlayer filter effects, if any, are subtle (on my gear, in my room, and to my ears);
convolution can make a rather big difference (although, whether it’s a difference for better or worse may depend on many factors.)



Interesting to hear people’s experiences on this given that up-sampling (and over-sampling) is such a significant concept within digital playback. With my previous DAC (an Arcam irDAC) I’d gone back and forth between having Roon sending the same sample-rate as the source material and up-sampling to 88.2/96. I never did any careful comparisons to establish whether I could hear any difference.

I’ve recently purchased a Chord Qutest and have Roon set up to send the source material as is on the belief that this DAC would do a better job of up-sampling although it would be interesting to hear from anyone else with this DAC.

After a few weeks I am definitely on the upsampling band wagon. To me it makes a positive difference. Just using Roon to upsample 192 PCM. Terrible now I am wondering about hqplayer, the audio bug is a horrible disease. But in all honesty I cannot imagine that with pcm upsampling hq can be so much better than Roon, since it would mean the price of the software and probably different hardware. So I guess I will stick with just Roon at the moment. Any thoughts or ideas on this?

I’m a little late to the party, but I don’t believe the Qutest upsamples.

It isn’t in the spec sheet.

HQPlayer, to myself and many others, and not wanting to discount those who think otherwise, but HQP is way way better at upsampling than Roon. That said, HQP has a learning curve and an unfriendly GUI. However, once you figure it out, HQP is easy to use. And with an armada of filter combinations, you can endlessly experiment.

I run HQP on a base model 2013 MacBook Pro. With HQP by itself, I can reliably get DSD 128. With Roon and HQP, I get DSD 64 for sure, and sometimes DSD 128. But my DAC upsamples to DSD 1024, so I’m happy with DSD 64.

HQP has a free trial, so there’s no initial risk to trying it out, beyond preferring HQP which will cost you :wink:

That is what I fear :wink: the trouble is HQP does not like my desktop PC , it installs but does not start.
I did not want to install it on my nuc, since that would not be powerful enough for Roon and hqp.
Also my Dac does not do DSD

Contact @jussi_laako, he may be able to help you get going. He’s the HQP developer and super devoted to supporting his excellent HQPlayer.

Not for me. Tried a few times makes zero difference to Naim kit so I save the CPU cycles for room correction instead.

Pretty much my conclusion as well. I do continue to futz around with upsampling (can’t help myself!) But it’s not like doubling the number of pixels in digital photos.

Just read this article from Archimago
Roon 1.6 Upsampling Digital Filter Options
Really interesting. Well I guess if he is happy with the filters, then I should also be and save a lot of cash :wink: Upsampling in Roon made a difference for me, so I will just enjoy it and not look for greener grass :slight_smile:

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I may have fundamentally misunderstood the technology/design ethos behind Chord DACs, then :smile:

Chord’s definitely upsample. They use Rob Watt’s custom design that uses linear filter with long taps. I don’t understand the whole concept but I like the results. Rob recommends only feeding the original source material. It’s not recommended to upsample beforehand or to even use MQA files. Only upsampling should be done thru m-scaler, which uses same custom design but with over a million taps.

You are basically paying the extra money for this custom filter. If you do want to see how it sounds with it bypassed you need to feed it a 768k signal. You can do this with roon or HQPlayer. I haven’t tried this since I got a Chord to move away from HQPlayer.


Yeah, I always send the native resolution of the files to the SBT>Qutest. Some of my listening is MQA files via TIDAL but they only represent a very small percentage of my overall listening and in any case sound ok to my ears :slightly_smiling_face:

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Yes MQA still sounds good but think if you’d compare to Qobuz with same hi-res file, you’d find that better. Vocals more realistic, little more air and space, and deeper sound stage. At least this is how I hear it thru Chord dacs.

I’m currently only using Tidal right now because cd quality is amazing thru Chord and Tidal has much bigger library.


I have HQP and the core on my NUC, which one are you running? Mine is a dual core i7 and it upsamples to DSD 256 no problem. Although I do note your current DAC doesn’t do DSD.

Qutest’s FPGA up-samples to ~90 MHz (PCM) and has an 11th order noise shaper running at ~104 MHz…


Qutest’s DSP is identical to Hugo2.

@dabassgoesboomboom, @iamoneagain, @norliss -

“What we have here, is a failure to communicate.” Probably on my end.

I read the link about the Chord. I see a lot about filters, but nothing about upsampling as in the sense of Roon’s DSP.

In other words, Qutest needs m-scaler to upsample.

MQA is not upsampling.

Qutest’s FPGA up-samples to ~90 MHz (PCM) and has an 11th order noise shaper running at ~104 MHz…

I’m confused… but we all know it’s not that hard to confuse me :grin:

Yes, evidently so am I.

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