[betula]

Hello everyone, a curiosity for those like me who uses Foobar, what do you prefer to use as an output module, Asio or Wasapi? I am currently using Asio and ask if anyone has made comparisons and which one prefers between the two ...
Thank you

There is no real sonic difference between the two. For me Wasapi crashed a little less often than Asio.

 

[Joe-Siow]

So I've had a few days with the M Scaler in my setup and here's my take on the M Scaler.

The one word that I keep going back to is "effortless". The M Scaler is really a marvelous piece of engineering.

With it in the setup, the improvement is very noticeable and significant.
Resolution is better, soundstage depth is deeper, music flows better and is more effortless and refined as a result.
The improvement is especially more substantial if you listen to genres like Classical and Jazz and high res files.

YMMV

 

[Hummer25]

So I've had a few days with the M Scaler in my setup and here's my take on the M Scaler.

The one word that I keep going back to is "effortless". The M Scaler is really a marvelous piece of engineering.

With it in the setup, the improvement is very noticeable and significant.
Resolution is better, soundstage depth is deeper, music flows better and is more effortless and refined as a result.
The improvement is especially more substantial if you listen to genres like Classical and Jazz and high res files.

YMMV

Good to hear Joe, this is exactly my experience of the m-scaler although I have only heard one with DAVE. I presume the benefits are the same with Qutest? A Qutest +m-scarler at £4000 is half the price of DAVE but not half the audio experience. I would guess it gets you to about 70-80% of DAVE.

 

[Joe-Siow]

Good to hear Joe, this is exactly my experience of the m-scaler although I have only heard one with DAVE. I presume the benefits are the same with Qutest? A Qutest +m-scarler at £4000 is half the price of DAVE but not half the audio experience. I would guess it gets you to about 70-80% of DAVE.

I have heard the Dave on its own, but not with Blu2 or M Scaler and it has been quite a while since I last heard the Dave, so it's tough to compare it to M Scaler + Qutest combo.

I thoroughly enjoyed the experience of having the M Scaler in my setup and I'm very sorry to see it go back to the dealer later today.

 

[FIOC]

1FS to 8FS input > 16FS WTA1 filter (49,152 taps) > 256FS WTA 2 filter > 3rd order 2048 FS filter > pulse array noise shaper at 104 MHz > analogue

When an M scaler is connected, the WTA1 filter is not used, and it is passed through to the 256 FS WTA 2 filter.

After reading Rob's signal path on page 37, I have some more specific questions regarding the signal paths of the 4 filter options, hope Rob and/or someone can help:
(1) Do I get the entire above-mentioned signal path in Qutest only when I select the "Incisive Neutral HF roll-off" filter option (Green)?

(2) If yes to (1) above, does the signal path for the "Incisive Neutral" filter option (white) look shorter like this below, skipping the 2048 FS filter and the pulse array noise shaper?
1FS to 8FS input > 16FS WTA1 filter (49,152 taps) > 256FS WTA 2 filter > analogue

(3) For "Warm" filter option and "Warm HF roll-off" filter option, do their signal paths look like below, respectively, both skipping the WTA 2 filter? Do I hear more audible distortions (warmth) with these two filters?
1FS to 8FS input > 16FS WTA1 filter (49,152 taps) > analogue
1FS to 8FS input > 16FS WTA1 filter (49,152 taps) > 3rd order 2048 FS filter > pulse array noise shaper at 104 MHz > analogue

(4) I recently got Roon subscription, running the Roon Core on my NAS and feeding the signal to Qutest DAC via dCS Network Bridge. I am still learning and evaluating Roon's upsampling function in the DSP engine. Based on the signal paths discussed above, it seems to me that any source input over 352.8 kHz (1FS to 8FS input) is meaningless, as Qutest will do the upsampling beyond 8FS (352.8 kHz) through WTA1 filter anyway. Did i understand this correctly?

(5) Due to the limitation on dCS network bridge's SPDIF output (capped at 192kHz/16 bit), i am using Roon to upsample all PCM sources to either 176.4 or 192, which sounds good to me when combining with the "Incisive Neutral HF roll-off" filter option. Am I doing this right to fit into the "1FS to 8FS input", or i should not upsample using Roon at all and just let the original sample rate, such as 44.1kHz, go directly into Qutest? My ears cannot give me a definite answer, as the differences are not significant, and are hard to tell if the differences are "better" or "worse". So want to hear some technical theories on this.

Thanks!

 

[Sound Eq]

hi everyone, can i ask in audirivana what settings do you use sox or izotope, and what settings did u dial in in either, can you please share

i played around with both, and do not know now what the defaults are anymore, can anyone also share the defaults for both

 

[Nejiro]

Excuse me a question about the M-Scaler, with the PCM files upsampling to 705.6 or 768 depending on the frequency of the file, with the DSD instead what does it bring them all to PCM 768? If for example I have a DSD256 "reduces" "to PCM 768?
Thank you

 

[x RELIC x]

(1) Do I get the entire above-mentioned signal path in Qutest only when I select the "Incisive Neutral HF roll-off" filter option (Green)?

No, you get the entire signal path with Green and White, but Green uses the HF filter where White does not.

2) If yes to (1) above, does the signal path for the "Incisive Neutral" filter option (white) look shorter like this below, skipping the 2048 FS filter and the pulse array noise shaper?
1FS to 8FS input > 16FS WTA1 filter (49,152 taps) > 256FS WTA 2 filter > analogue

No, see above. Also, you can not bypass the Pulse Array DAC. It's the digital filter that is changed.

3) For "Warm" filter option and "Warm HF roll-off" filter option, do their signal paths look like below, respectively, both skipping the WTA 2 filter? Do I hear more audible distortions (warmth) with these two filters?
1FS to 8FS input > 16FS WTA1 filter (49,152 taps) > analogue
1FS to 8FS input > 16FS WTA1 filter (49,152 taps) > 3rd order 2048 FS filter > pulse array noise shaper at 104 MHz > analogue

Not sure if you are hearing more distortions, but as I understand it the WTA2 filter is more accurate for reconstructing the signal, which is why the WTA1 is supposed to sound warmer / smoother. It's a timing difference that it changes, which can change timbre. Personally, on the Hugo2 I had a hard time hearing a difference between filters until I listened for timing and space in the music. If I just listened for a frequency response change I couldn't really tell them apart. it comes down to how one perceives it I suppose.

4) I recently got Roon subscription, running the Roon Core on my NAS and feeding the signal to Qutest DAC via dCS Network Bridge. I am still learning and evaluating Roon's upsampling function in the DSP engine. Based on the signal paths discussed above, it seems to me that any source input over 352.8 kHz (1FS to 8FS input) is meaningless, as Qutest will do the upsampling beyond 8FS (352.8 kHz) through WTA1 filter anyway. Did i understand this correctly?

See below.

(5) Due to the limitation on dCS network bridge's SPDIF output (capped at 192kHz/16 bit), i am using Roon to upsample all PCM sources to either 176.4 or 192, which sounds good to me when combining with the "Incisive Neutral HF roll-off" filter option. Am I doing this right to fit into the "1FS to 8FS input", or i should not upsample using Roon at all and just let the original sample rate, such as 44.1kHz, go directly into Qutest? My ears cannot give me a definite answer, as the differences are not significant, and are hard to tell if the differences are "better" or "worse". So want to hear some technical theories on this.

Ideally, don't change the sampling rate from the original file and just feed Chord DACs bit perfect files at their original sampling rate. Rob has answered this 'technically' before (I can't find it), but it comes down to the WTA filters doing a better job than software upsamplers. Of course, if you prefer the sound of upsampling from Roon then that's what you should choose, but it won't be as accurate as the WTA filter, according to Rob.

 

[FIOC]

Thanks Relic! Just to confirm I get it right...

No, you get the entire signal path with Green and White, but Green uses the HF filter where White does not

Is “HF filter” you mentioned = “3rd order 2048 FS filter” in Rob’s signal path? Or HF filter is not showing in the signal path description at all?

Not sure if you are hearing more distortions, but as I understand it the WTA2 filter is more accurate for reconstructing the signal, which is why the WTA1 is supposed to sound warmer / smoother. It's a timing difference that it changes, which can change timbre. Personally, on the Hugo2 I had a hard time hearing a difference between filters until I listened for timing and space in the music. If I just listened for a frequency response change I couldn't really tell them apart. it comes down to how one perceives it I suppose.

I remember seeing Rob commented before that other DACs do not bother to filter above 20khz so they are hearing more audible distortions; therefore, I was guessing if the two “Warm” filters indeed disable WTA2 filter, they essentially make Qutest similar to “other DACs”, which however makes sense as someone may like the distortion as it adds warmth (nothing wrong about it). I could be wrong.

Ideally, don't change the sampling rate from the original file and just feed Chord DACs bit perfect files at their original sampling rate. Rob has answered this 'technically' before (I can't find it), but it comes down to the WTA filters doing a better job than software upsamplers. Of course, if you prefer the sound of upsampling from Roon then that's what you should choose, but it won't be as accurate as the WTA filter, according to Rob.

Your opinion makes sense to me as I also believe less is more in audio. My problem is that my ears cannot tell me “better” or “worse” by upsampling in Roon, but I always wonder why ppl are so into Roon upsampling, even including my hardcore local dealer who highly believes in dCS DACs but still recommends me using Roon upsampling (they are not pushing me to buy Nucleus) before dCS internal upsampling. So I am afraid I am missing something there. With that said, back to Rob’s signal path, isn’t what Roon upsampling is doing only limited to the “1FS to 8FS input” stage, but not intervening WTA1 or WTA2 at all which upsample the signal to very high frequency that Roon won’t be able to touch? I have no doubt Qutest does better job in upsampling than Roon, if they both do upsampling for the same frequency range. Based on the numbers showing and that I only upsample PCM to 176 or 192 in Roon, there seem to be no overlap in the signal path that Roon would distort Qutest’s internal upsampling. Am I thinking the wrong way?


One more question - I went to a local dealer to try the M-Scaler over the past weekend. I did not make appointment so I was only able to listen to the Hugo TT2 + M-Scaler combo with headphones. Not sure if headphone cannot reveal all benefits, I honestly could not hear much difference between with and without M-Scaler. Does M-Scaler only takes care of the “16FS WTA1 filter” in the signal path, and the Qutest DAC will take care of the remaining processing? Since WTA2 filter is so important in recovering transients and timing, why not let M-Scaler take care of that step too?

Does the WTA2 filter in Qutest also have 49,152 taps?

Thanks!

 

[x RELIC x]

Is “HF filter” you mentioned = “3rd order 2048 FS filter” in Rob’s signal path? Or HF filter is not showing in the signal path description at all?

The high frequency filter is just that, a filter added on top of the signal processing (like the crossfeed), and not the 2048FS filter. Edit: Rob clarified that the HF filter alters the 2048FS, but doesn't bypass it, as outlined in a couple posts down the page - Link. Both Green and Red settings use the HF filter, while White and Orange do not.

I remember seeing Rob commented before that other DACs do not bother to filter above 20khz so they are hearing more audible distortions; therefore, I was guessing if the two “Warm” filters indeed disable WTA2 filter, they essentially make Qutest similar to “other DACs”, which however makes sense as someone may like the distortion as it adds warmth (nothing wrong about it). I could be wrong.

Yes, the Orange and Red settings disable the WTA2 stage, but I would say it's still very far from 'other DACs' just because of this. Rob said he included the different settings because he thought it would be interesting for people to hear the difference between just using WTA1 and using WTA1+WTA2. Again, this does not make it like other DACs as no other DAC uses a WTA (Watts Transient Aligned) filter. Again, Rob says it's perceived as warmer because it's less incisive in the timing and starting and stopping of notes, smoother/softer, which also affects timbre.

Your opinion makes sense to me as I also believe less is more in audio. My problem is that my ears cannot tell me “better” or “worse” by upsampling in Roon, but I always wonder why ppl are so into Roon upsampling, even including my hardcore local dealer who highly believes in dCS DACs but still recommends me using Roon upsampling (they are not pushing me to buy Nucleus) before dCS internal upsampling. So I am afraid I am missing something there. With that said, back to Rob’s signal path, isn’t what Roon upsampling is doing only limited to the “1FS to 8FS input” stage, but not intervening WTA1 or WTA2 at all which upsample the signal to very high frequency that Roon won’t be able to touch? I have no doubt Qutest does better job in upsampling than Roon, if they both do upsampling for the same frequency range. Based on the numbers showing and that I only upsample PCM to 176 or 192 in Roon, there seem to be no overlap in the signal path that Roon would distort Qutest’s internal upsampling. Am I thinking the wrong way?

Old habits die hard? I dunno and can't speak for others preferences, but I trust when Rob says don't upsample and muck with the file as his DACs upsample to a ridiculous amount anyway and do it very well compared to conventional upsamplers. He's written extensively on the topic.

One more question - I went to a local dealer to try the M-Scaler over the past weekend. I did not make appointment so I was only able to listen to the Hugo TT2 + M-Scaler combo with headphones. Not sure if headphone cannot reveal all benefits, I honestly could not hear much difference between with and without M-Scaler. Does M-Scaler only takes care of the “16FS WTA1 filter” in the signal path, and the Qutest DAC will take care of the remaining processing? Since WTA2 filter is so important in recovering transients and timing, why not let M-Scaler take care of that step too?

I wouldn't say that the M scaler is not suited for headphones as many people have reported great improvements with headphones using the M scaler. What headphones did you use?
As with all your questions it's best if you asked Rob about the WTA1 vs WTA2 filter. As I understand it the actual TAPs exist in WTA1 so the M scaler is replacing the 49,152 actual TAPs in the Qutest with 1 million TAPs in the M scaler.

Does the WTA2 filter in Qutest also have 49,152 taps?

AFAIK the WTA2 filter will add to the WTA1 actual TAPs of 49,152, so in a sense the answer is yes. Rob covered it at some point in one of his many posts.

You really should just read all of Rob's posts for a better understanding if you are curious about these details as I may be misquoting something. Or just ask him yourself.

Here is a quote I found for you that may help your understanding:

Moving on to the filter selection. Now providing the option of adjustable filters very much goes against my purist design philosophy; the 256 FS filter (white or green) is the technically more accurate filter, in that the reconstruction of transient timing is more accurate to the original analogue signal in the ADC, and in the past I would have simply given that. But I included the option for two reasons; firstly as it provides a simple way of getting yin-yang balance, even if we are using an inaccuracy to enable that, and that's OK so long as people are aware of that fact. When you get better headphones, then ideally the incisive filter options will be the best. The second reason was to demonstrate that actually very subtle technical differences can have a profound subjective effect. The technical difference between the 256 FS filter and 16 FS is very subtle; both options employ digital filtering up to 2048 FS, but the 16 FS option is just IIR filters (analogue type filter) and the 256 FS replaces the 16>256 IIR filter with a WTA filter (an FIR filter) which will re-construct the timing much more accurately. But the difference technically is very small. Note that conventional chip DAC's employ no filtering whatsoever above 8 FS or 16 FS (that's 384 kHz and 768 kHz max respectively).

Now although the technical difference is very small, to me the sound quality difference is very much not small. And it does sound very different to a normal WTA filter - you do not get the usual changes in sound quality, but you can perceive the starting and stopping of notes more easily - and because it's like snapping everything into focus, it sounds sharper and more incisive. When you can't hear the starting and stopping of notes, things sound soft and warm. Indeed, poor timing reconstruction is another way where you can soften up the sound - but again it's unnatural, as everything sounds soft, even sharp percussive effects that in real life sound sharp and fast.

To me the change is not small - so I was disappointed that a lot of posters were initially saying that they could not hear much of a change. Maybe I am a hyper-sensitive listener - or more likely the change is much more apparent when you are not doing AB tests, but are listening long term to music, and your brain has learnt about the better accuracy that Hugo 2 offers. But it's good to hear posters starting to report the change that I hear.

 

[FIOC]

Thanks again Relic! I have no further questions on this, and will find time to read Rob’s posts.

As far as the headphones used, the dealer first gave me Sennheizer HD 820 to listen, which however was very harsh on the highs. So I requested an auduze LCD3, which was warmer but lacked transparency. Anyway, I could not hear much benefit of M Scaler.

 

[jacobacci]

I have a Chord Hugo 2 and I am very happy with it.
Now I am considering getting a Chord Qutest to upgrade my second system. That system has active Piega P8LTD speakers. The setup I am considering is to set the Qutest to 1V output and then use Roon's digital volume control to adjust the volume. Is this setup likely to yield good results vs. having a dedicated preamp for volume control?

 

[blueninjasix]

I have a Chord Hugo 2 and I am very happy with it.
Now I am considering getting a Chord Qutest to upgrade my second system. That system has active Piega P8LTD speakers. The setup I am considering is to set the Qutest to 1V output and then use Roon's digital volume control to adjust the volume. Is this setup likely to yield good results vs. having a dedicated preamp for volume control?

I bought a Khozmo passive pre amp to use between Qutest and my SET power amps but I've recently removed it and use Foobar to attenuate the volume slightly (3db). I think I get increased transparency this way. Oh how I wish the Qutest had digital volume control........

 

[Rob Watts]

Just to clarify on @x RELIC x excellent replies (thanks you have saved me a lot of time today and many times in the past!) the HF filter isn't something added that's extra - and I often actually imply that by posting that one engages the HF filter - what actually happens is the time constants of the 2048FS filter is changed, not a signal path being switched. So with no HF filter the -3dB point of the 2048FS filter is 150 kHz; with the HF filter engaged it changes to 37.5 kHz.

 

[Bill13]

Haven't been able to find an answer to the following question, so maybe Rob Watts or somebody knowledgeable could answer:

I just received my new M-scaler today and connected it to my Qutest via supplied dual-BNC cables..

I'm playing music DVDs (44 kHz sample rate CD player is connected to the M-scaler BNC 1 input connector).
The M-scaler is connected to my Qutest DAC using dual-BNC connection for the 705kHz sample rate (only the dual-BNC input to Qutest at 705 kHz sample rate can utilize the full 1 million M-scaler taps).

For the Qutest dual-BNC input connection, the input led-light button is blue color. Problem is, the Qutest user manual has no documentation on how to determine that the dual-bnc input SR is either 705 kHz (for 1M taps) or 352.8 kHz for only 1/2 million taps (Qutest manual not does not mention input button blue color for dual-BNC input selection). Only YELLOW and RED button colors for Qutest BNC 1 & 2 inputs are mentioned in the manual.

Is this blue color input button light for dual-BNC 705 kHz input SR an undocumented feature of Qutest? - or is there something wrong with my Qutest?