To upsample or not to upsample

(Dom) #1

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:

(Tom Keenan) #2

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.)

YMMV.

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#3

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.

(Dom) #4

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?

#5

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

It isn’t in the spec sheet.

#6

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:

(Dom) #7

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

#8

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.

#9

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

(Tom Keenan) #10

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.

(Dom) #11

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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#12

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

#13

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.

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#14

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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#15

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.

#16

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.

#17

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

@norliss

https://www.head-fi.org/threads/chord-electronics-qutest-dac-official-thread.869417/page-3#post-13966180

Qutest’s DSP is identical to Hugo2.

#18

@lkjhgdaa, @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.

#19

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:

#20

Yes, evidently so am I.

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