Chord quest, Vs Rme adi-2 dac fs + tap count.

[Gurra1980]

Chord DACs tend to have that effect.

Haha bought it used, so I have no problem really, might sell it buy a d90 and an minidsp studio instead. Haha many options now. What should I do. I hate my room.

 

[Zensō]

Haha bought it used, so I have no problem really, might sell it buy a d90 and an minidsp studio instead. Haha many options now. What should I do. I hate my room.

The fact that you’re now focused on your room is a big step in the right direction. Step one, sell the Chord...

 

[mansr]

Right. To that I can only ask, "how come". Is the premise of Chord's scaler, besides insanely overkill, also a marketing lie? Or is what Stereophile measured basically the target they intended...?

It's possible that they messed up the measurements, though if that were the case, I would've expected a complaint from Chord and prompt grovelling apology by JA. Maybe all those taps are wasted on a needlessly narrow transition band. That would be consistent with the published graphs.

 

[bikeguy]

I've owned a Chord Qutest for over a year. I recently demoed the Gustard X16 dac that was measured favorably on this site. I wanted to try out MQA full decode as I subscribe to Tidal and to determine if there was any difference between the two other than price. My experience was that there was no difference in sound quality that I could detect using the same cables (usb in/rca out) and streamer (Auralic Aries G1) on the dacs. I recently sold the Qutest. The Qutest is a very nice, well built dac and I don't have anything negative to say about it. I now have a bit extra cash to help out with my upcoming subwoofer purchase. A bit off topic, sorry.

 

[Veri]

The Qutest is a very nice dac and I don't have anything negative to say about it. I now have a bit extra cash to help out with my upcoming subwoofer purchase. A bit off topic, sorry.

Imo that's a negative, haha. Costing more; not doing anything appreciably better. In any case, probably a good decision from the sound of it

 

[Gurra1980]

I've owned a Chord Qutest for over a year. I recently demoed the Gustard X16 dac that was measured favorably on this site. I wanted to try out MQA full decode as I subscribe to Tidal and to determine if there was any difference between the two other than price. My experience was that there was no difference in sound quality that I could detect using the same cables (usb in/rca out) and streamer (Auralic Aries G1) on the dacs. I recently sold the Qutest. The Qutest is a very nice, well built dac and I don't have anything negative to say about it. I now have a bit extra cash to help out with my upcoming subwoofer purchase. A bit off topic, sorry.

The Gustard seems interesting, a lot cheaper than even the D90. Will check that one out.

 

[Tks]

If you want to waste an hour, watch it.
In there he claims there that it is easy to hear a difference between -180db noise shaper and -200db noise shapper. He also claims that distortion between -130db and -150db is easily audible. And lots more claims that are just fantastical and without any proof. Empty claims.
So, whatever he says.... doesn't mean a lot.
Just because of those and ridiculous industrial design of Chord dacs I would never buy them. Not to mention the price for unbalanced equipment with 50 shades of color....

Classic.

 

[Gurra1980]

How much maths have you studied?

The filters we're talking about can be represented as y(n) = b0 * x(n) + b1 * x(n - 1) * b2 * x(n - 2) ... bM * x(n - M), where x(n) is the input value of sample number n and y(n) is the corresponding output. Put differently, output sample n is a linear combination of the input sample and the M prior input samples. The constants b0 ... bM are the coefficients, and they are also equal to the impulse response of the filter. Graphically, the filter can be represented like this:

Here we can easily see that the input signal is "tapped" at M+1 places in order to produce the output. The number M is also known as the order of the filter. Without going into detail, the higher the filter order, the closer it can be made to approximate a desired response.

An ideal low-pass filter, which is what we're aiming for, has a perfectly flat frequency response up to the cut-off, above which the input is fully attenuated. This is only possible with an infinitely long sinc filter, so some compromise is necessary. The deviation from the ideal can be described in terms of passband flatness (ripple), stop-band attenuation, and width of the transition band.

Suppose we want to resample CD audio to twice its original rate. We want to minimise ripple below 20 kHz and maximise attenuation above 22 kHz (half the input sample rate). The interval between 20 kHz and 22 kHz, transition band, is unimportant. It is inaudible, and besides, the recording/production process has probably already mangled the content in that range.

First, consider a case with modest requirements, 0.1 dB passband ripple and 80 dB stopband rejection. Plugging these constraints into the Matlab filter designer using the equiripple method, we get a filter of order 147 (that's 148 taps) with this magnitude response:
View attachment 122159

Zooming in on the passband, we can see that the ripple meets the requirement:
View attachment 122160

This might be good enough for, say, a portable audio player where cost and power consumption are more important than extreme performance. We are, however, building a high-end system and want something better. Hence, we tighten the specification to 0.0001 dB passband ripple and 180 dB stopband rejection. This produces a filter of order 394, and the magnitude response looks exactly as requested:
View attachment 122163

This level of performance far exceeds all established limits of audibility. Furthermore, it exceeds the capabilities of any amplifier. This is where any reasonable person would stop and call it good enough. But what if, like Rob Watts, we are not reasonable and believe we can hear things at -300 dB? Matlab can help. The equiripple design method doesn't work with this constraint, so we switch to the window method. Using a cut-off frequency of 21 kHz and suitable window parameters, we get a filter of order 1000 with this response:
View attachment 122169

Passband ripple is virtually non-existent (note the scale on the y axis):
View attachment 122170

Given the analogue limitations imposed by physical reality, overkill doesn't begin to describe this. And yet Rob Watts wants to use a filter that is ONE THOUSAND times longer again. It's beyond ludicrous.

It should also be noted that in the M-scaler tests published by Stereophile, it doesn't come anywhere close even to the second filter shown above, so all those taps are essentially wasted.

This post was amazing! Just what I wanted, will try to get a grasp on what everything means and probably learn a lot! Thanks!

 

[BDWoody]

This post was amazing! Just what I wanted, will try to get a grasp on what everything means and probably learn a lot! Thanks!

That makes all those patient answers to all the disingenuous trolls worth it, doesn't it @mansr ?

 

[mansr]

That makes all those patient answers to all the disingenuous trolls worth it, doesn't it @mansr ?

Making fun of Rob Watts is always worth it.

 

[Count Arthur]

If you want to waste an hour, watch it.
In there he claims there that it is easy to hear a difference between -180db noise shaper and -200db noise shapper. He also claims that distortion between -130db and -150db is easily audible. And lots more claims that are just fantastical and without any proof. Empty claims.
So, whatever he says.... doesn't mean a lot.
Just because of those and ridiculous industrial design of Chord dacs I would never buy them. Not to mention the price for unbalanced equipment with 50 shades of color....

Wait a minute, if the differences between these -150 to -200db noise shapers is clearly audible despite, according to engineers, being well below audible threshhold, what is the source file and what what was that recorded on? Presumably something with far lower specs, so is he claiming that his equipment can make up for that, or am I missing something?

 

[bikeguy]

The Gustard seems interesting, a lot cheaper than even the D90. Will check that one out.

For me, price was not the main driver. I wanted to take advantage of the MQA full decode ability and, Amazon had it available so a return would be easy if I did not like it. The bonus I discovered is that it sounded just as good as the Qutest to my ears in my system and now I have full MQA decoding which is pretty good for the most part (The Doors MQAs definitely sound better than my cd rips).

 

[DomieMic65]

Following the thread!
I was between Qutest and ADI and finally went with the RME.
Quite(very) pleased with it but I always would like to listen the Qutest in my system.

 

[Gurra1980]

Following the thread!
I was between Qutest and ADI and finally went with the RME.
Quite(very) pleased with it but I always would like to listen the Qutest in my system.

As others has stated, probably no sound difference. I actually ordered the Gustard x16, from Amazon, will blind test it and compare it to my qutest.

 

[PierreV]

or am I missing something?

Yes, willing suspension of disbelief.

 

[Gurra1980]

I did a little blind test with my new Gustard x16 and my old qutest, using tidal hifi, optical in, via Vincent sv-237, and triange esprit antlal (I know I know they don't measure well, but I love the sound and they are extremely resolving with their horn tweeters and I know them very well) the voltage was set to 2volt on both DACs, I listened to two tracks, Josefine cronholm, in your wild garden, and Nils Lofgren, Keith don't go. One interesting thing I noticed was that the more I listened the more it sound the same each time, the first times it was a big difference each time I heard the song. So it seems the less you know a song the more different it sounds each time (although I already knew these song pretty well) so my results then, 8 listens (that was the maximum my girlfriend could take )4 times I was right and 4 times I was wrong. I will sell the Qutest.

 

[DomieMic65]

No USB testing/listening?

 

[Gurra1980]

No USB testing/listening?

Maybe in the future, I don't have any computer near, or time to do more tests right now, it will be used from television, ldac Bluetooth, or maybe in the future with a dedicated streamer if I can decern a difference in sound quality.

 

[bikeguy]

I did a little blind test with my new Gustard x16 and my old qutest, using tidal hifi, optical in, via Vincent sv-237, and triange esprit antlal (I know I know they don't measure well, but I love the sound and they are extremely resolving with their horn tweeters and I know them very well) the voltage was set to 2volt on both DACs, I listened to two tracks, Josefine cronholm, in your wild garden, and Nils Lofgren, Keith don't go. One interesting thing I noticed was that the more I listened the more it sound the same each time, the first times it was a big difference each time I heard the song. So it seems the less you know a song the more different it sounds each time (although I already knew these song pretty well) so my results then, 8 listens (that was the maximum my girlfriend could take )4 times I was right and 4 times I was wrong. I will sell the Qutest.

I just swapped the Chord out and put the Gustard in its place. Let it go for a few days. I thought it all sounded good from the start. I put the Qutest back in and it still all sounded good. It was then I felt there really was not much difference between the two. The Qutest as mentioned is sold and my new subs have arrived. The Qutest sale helped out a bit. Enjoy the music.

 

[Gurra1980]

I just swapped the Chord out and put the Gustard in its place. Let it go for a few days. I thought it all sounded good from the start. I put the Qutest back in and it still all sounded good. It was then I felt there really was not much difference between the two. The Qutest as mentioned is sold and my new subs have arrived. The Qutest sale helped out a bit. Enjoy the music.

Great! And whatever you do... Enjoy the music.