[Sonic77]

Haahaa can you imagine. Many DACs enter one dac leaves. Bunch of designers with their DACs out for blood. Rob would need to redesign the Dave to be longer and more to a point.

 It would go something like this

 

[Mython]

 

Haahaa can you imagine. Many DACs enter one dac leaves. Bunch of designers with their DACs out for blood. Rob would need to redesign the Dave to be longer and more to a point.

 It would go something like this

 
 
 

Since so many 'high-end audiophiles' think with their wallet first, their eyes second, their ears third, and their emotions a poor fourth, I think we all know that the way to silence all the nay-sayers would be for Rob & John to charge $200k for DAVE.
 
Job done.
 
Problem solved.
 
(JOKE, John & Rob - thankyou for not playing the high-end price-gouging game, and please don't be tempted to!

)

 

[esimms86]

@ecwl, Hq player is a bit difficult to set. can you please give the link for the best sq setting in Hq player ? i want to compare through mojo , an unaltered CD quality stream via foobar and upsampled stream from Hq player !

Go to www.soundgalleries.com and then click on "Articles."

 

[ecwl]

Go to www.soundgalleries.com and then click on "Articles."

Except the article recommended a DSD setting which would be fine for a "native" DSD DAC but suboptimal for Chord Mojo according to the Computer Audiophile forum discussion. So we are back to what is the best PCM setting. According to the HQPlayer website (without downloading the program), there are
 

Resampling filters:

1. 8 linear phase
2. 5 minimum phase
3. 3 impulse optimal
4. 2 closed form

 

Dithers and noise-shapers:

1. 4 dithers
2. 4 noise shapers

 
Moreover, each of the filters and noise-shapers have their own settings. Don't get me wrong, I strongly suspect HQPlayer is great. But mainly for the tweakers... It's almost like asking Rob Watts to let us run a computer program so that we can sync with the Chord DAVE and tweak the FPGA so that we can choose our own WTA algorithm and noise shaper.

 

[REXNFX]

 
 
This just got in! Will be doing an extensive review for a local magazine in the upcoming month. Running in for a couple of weeks right now with Mass Kobo 394 and HEK and will be hooking this up to my reference 2 ch. system with Aurender W20 / Esoteric K01X / Gryphon / Magnepan 20.7 after testing it with various headphones. Stay tuned....

Very nice! Particularly looking forward to the comparison v your turntable....

 

[shuttlepod]

 
 
This just got in! Will be doing an extensive review for a local magazine in the upcoming month. Running in for a couple of weeks right now with Mass Kobo 394 and HEK and will be hooking this up to my reference 2 ch. system with Aurender W20 / Esoteric K01X / Gryphon / Magnepan 20.7 after testing it with various headphones. Stay tuned....

 
I'm sure some folks would be interested in whether you find that the DAVE is sensitive to the Aurender W20. In other words, could you compare the DAVE with both the W20 and a stock computer and note what differences, if any, you find?

 

[esimms86]

Except the article recommended a DSD setting which would be fine for a "native" DSD DAC but suboptimal for Chord Mojo according to the Computer Audiophile forum discussion. So we are back to what is the best PCM setting. According to the HQPlayer website (without downloading the program), there are

Resampling filters:

• 8 linear phase
• 5 minimum phase
• 3 impulse optimal
• 2 closed form

Dithers and noise-shapers:

• 4 dithers
• 4 noise shapers

Moreover, each of the filters and noise-shapers have their own settings. Don't get me wrong, I strongly suspect HQPlayer is great. But mainly for the tweakers... It's almost like asking Rob Watts to let us run a computer program so that we can sync with the Chord DAVE and tweak the FPGA so that we can choose our own WTA algorithm and noise shaper.

ecwl, I don't at all dispute what you've said, however, Miska has designed hqplayer to be used by people with a significantly higher than average amount of computer expertise and the link I cited is the only place I know of on the web that gives any kind of primer on using hqp.

 

[holeout]

 
Remember to take out your Gryphon Pandora preamplifier when testing out the Chord DAVE and use the power cable for the Pandora for the DAVE. Unless the power cables are the same. I think it'll be interesting for you.
 
And I wonder if you can help rayleemw find a local dealer in Hong Kong for the Chord DAVE. Heck, invite the guy over...

Will definitely try Dave direct to the Grypon monoblocks,should be an interesting comparison, I use Vertere HB cables throughout my system and will be trying different power cables with Dave. Any fellow headfiers in HK interested in listening to the Dave, please PM me.
 

   
Congrats! But I wonder: What has the Mass Kobo 394 to do with running in (DAVE or its headphone output?) or driving the HE1000?

Nothing, just running in with different modes (DAC/digital pre/headphone) and outputs on Dave as it may be connected to my systems in various ways. 
 

   
I'm sure some folks would be interested in whether you find that the DAVE is sensitive to the Aurender W20. In other words, could you compare the DAVE with both the W20 and a stock computer and note what differences, if any, you find?

Yes, comparing different sources (W20, Macbook, ipad pro, K01X, AK380 Cu) to the Dave with different input options (USB/optical/AES) is in the plan. 
 
I have been using the Hugo for my portable setup since it first came out and right out from the box Dave bears a familiar sound signature, with better staging, resolution and micro details. Impressive!

 

[Rob Watts]

   
I think I understand it. Perfect low-pass filtering means infinite Q means infinite ringing. Infinite Q means that just the resonance frequency itself is affected by the ringing, every frequency below is perfectly reproduced in the time domain (although that's impossible to measure). Any (real-world) low-pass filter with a finite Q factor will introduce transient corruption below the filter frequency to some degree. Right?
 
So DAVE approaches an infinite Q factor? I've seen measuring data indicating –0.04 dB at 20 kHz, which is pretty good.
 
However, in the real (non-DAVE) world avoiding pre-ringing may be beneficial, at least the corresponding filter 3 on my Corda Symphony sounded special to my ears (sometimes I considered it the best).

I haven't thought of it that way - thinking in terms of Q - but it makes sense and is a good way of looking at it.
 
But the first stage WTA filter is way better than 0.04dB - that's a symptom of other filters (notably the analogue ones). Looking at the results from the actual filter used in the FPGA (quantized coefficients) the frequency response is +0.000003 dB at 23 kHz (48 KHz sample rate). Its still within +/- 0.3 dB at 23.970 kHz - so that is only 30 Hz away from the critical FS/2 point.
 
I do not think people appreciate how sophisticated Dave's DSP actually is; with 166 DSP cores running in parallel, it works out at a staggering 0.1 Tera instructions per second (TIPS) and that's just the WTA filtering - the further interpolation, filtering and noise shaping is getting on for another 0.1 TIPS. 
 
But the point I am trying to make is that impulse response is not a good way of looking at filter performance, as we are talking about using an illegal non bandwidth limited signal. And people make the mistake that a small amount of ringing is a good thing and is evidence of good time domain performance - when it is not. When I talk about time domain performance I am talking about how well the filter reconstructs the timing of the original and you can have a low amount of ringing that has quite good timing, against a longer ringing filter that is actually worse timing. Of course, an infinite amount of ringing with an ideal sinc response will perfectly reproduce a bandwidth limited signal with no changes whatsoever - and this is what high end audio is supposed to be about. I can gain a much more accurate predictor of sound quality just looking at the total output using 0 dBFS random noise. In short talking about ringing is a red herring.
 
Rob

 

[analogmusic]

The main effect I noticed with Hugo and Mojo (and hopefully Dave sometime soon if I can audition this in Dubai), is the free flow of music.
 
There seems to be no stress of listening to music on Hugo and Mojo, it just flows, like analog recordings and live music.
 
Whatever the engineering is, at the end of the day, a DAC has to perform musically, and I am very happy with musical performance of Hugo and Mojo.
 
Other than Piano notes being very clear, I am also noticing that drums have that impact, I guess the starting and ending of notes is clear and not blurred anymore so much easier to hear and enjoy snare drums.

 

[JaZZ]

  The main effect I noticed with Hugo and Mojo (and hopefully Dave sometime soon if I can audition this in Dubai), is the free flow of music.
 
There seems to be no stress of listening to music on Hugo and Mojo, it just flows, like analog recordings and live music.
 
Whatever the engineering is, at the end of the day, a DAC has to perform musically, and I am very happy with musical performance of Hugo and Mojo.
 
Other than Piano notes being very clear, I am also noticing that drums have that impact, I guess the starting and ending of notes is clear and not blurred anymore so much easier to hear and enjoy snare drums.

 
DAVE offers even much more of this very quality.

 

[lovethatsound]

DAVE offers even much more of this very quality.

Total agreed with you jaZZ

 

[Mython]

 

  The main effect I noticed with Hugo and Mojo (and hopefully Dave sometime soon if I can audition this in Dubai), is the free flow of music.
 
There seems to be no stress of listening to music on Hugo and Mojo, it just flows, like analog recordings and live music.
 
Whatever the engineering is, at the end of the day, a DAC has to perform musically, and I am very happy with musical performance of Hugo and Mojo.
 
Other than Piano notes being very clear, I am also noticing that drums have that impact, I guess the starting and ending of notes is clear and not blurred anymore so much easier to hear and enjoy snare drums.

 
DAVE offers even much more of this very quality.

 
 
Yes, but DAVE requires much larger pockets, in more ways than one!

 

[JaZZ]

 

   
I think I understand it. Perfect low-pass filtering means infinite Q means infinite ringing. Infinite Q means that just the resonance frequency itself is affected by the ringing, every frequency below is perfectly reproduced in the time domain (although that's impossible to measure). Any (real-world) low-pass filter with a finite Q factor will introduce transient corruption below the filter frequency to some degree. Right?
 
So DAVE approaches an infinite Q factor? I've seen measuring data indicating –0.04 dB at 20 kHz, which is pretty good.
 
However, in the real (non-DAVE) world avoiding pre-ringing may be beneficial, at least the corresponding filter 3 on my Corda Symphony sounded special to my ears (sometimes I considered it the best).

I haven't thought of it that way - thinking in terms of Q - but it makes sense and is a good way of looking at it.
 
But the first stage WTA filter is way better than 0.04dB - that's a symptom of other filters (notably the analogue ones). Looking at the results from the actual filter used in the FPGA (quantized coefficients) the frequency response is +0.000003 dB at 23 kHz (48 KHz sample rate). Its still within +/- 0.3 dB at 23.970 kHz - so that is only 30 Hz away from the critical FS/2 point.
 
I do not think people appreciate how sophisticated Dave's DSP actually is; with 166 DSP cores running in parallel, it works out at a staggering 0.1 Tera instructions per second (TIPS) and that's just the WTA filtering - the further interpolation, filtering and noise shaping is getting on for another 0.1 TIPS. 
 
But the point I am trying to make is that impulse response is not a good way of looking at filter performance, as we are talking about using an illegal non bandwidth limited signal. And people make the mistake that a small amount of ringing is a good thing and is evidence of good time domain performance - when it is not. When I talk about time domain performance I am talking about how well the filter reconstructs the timing of the original and you can have a low amount of ringing that has quite good timing, against a longer ringing filter that is actually worse timing. Of course, an infinite amount of ringing with an ideal sinc response will perfectly reproduce a bandwidth limited signal with no changes whatsoever - and this is what high end audio is supposed to be about. I can gain a much more accurate predictor of sound quality just looking at the total output using 0 dBFS random noise. In short talking about ringing is a red herring.
 
Rob

 
That's impressive indeed. And I'm glad that the (filter) theory matches the sonic impression I get from DAVE – and vice-versa.
 
Actually it's strange that FM radio never suffered from the sterile sound attributed to digital recordings, despite being dependent on a very similar steep low-pass filter for suppressing the pilot tones carrying the two stereo channels. And I'm rather sure that the FM technology produces a lot of modulation noise as well. I've always suspected the reason for the warmth of FM sound (as opposed to the coldness of – particularly early – digital recordings) might be that these components – filter resonance and modulation noise – are masked by a generally high level of harmonic distortion. Whereas the «clean» digital recordings make these shortcomings blatantly obvious.

 

[JaZZ]

 

 

  The main effect I noticed with Hugo and Mojo (and hopefully Dave sometime soon if I can audition this in Dubai), is the free flow of music.
 
There seems to be no stress of listening to music on Hugo and Mojo, it just flows, like analog recordings and live music.
 
Whatever the engineering is, at the end of the day, a DAC has to perform musically, and I am very happy with musical performance of Hugo and Mojo.
 
Other than Piano notes being very clear, I am also noticing that drums have that impact, I guess the starting and ending of notes is clear and not blurred anymore so much easier to hear and enjoy snare drums.

 
DAVE offers even much more of this very quality.

 
Yes, but DAVE requires much larger pockets, in more ways than one!

 
Sad, but true!

Let's hope we won't become too elitist with our DAVEs – possibly the best digital source and headphone amp on the planet to date!