NOS DAC sound more natural

[Jud]

I actually have quite a few hi-res recordings that sound worse than their 44.1khz counter part. We live in the digital dark ages...

 

44.1 != no sample rate or format conversion when speaking of the ADC, any more than it does for most DACs.

[ilok]

44.1 != no sample rate or format conversion when speaking of the ADC, any more than it does for most DACs.

 

There's quite a few release that takes 44.1khz and upsamples it and calls it hi-res and charge you more.

[Jud]

But the reason NOS sounds more natural: read http://www.metrum-acoustics.com/Design%20Philosophy%20Metrum%20Acoustics.pdf

 

Just look at the waveform.

 

Yes, but this is half the story.

 

The type of gentle roll-off used as a filter by the Metrum is very good at eliminating "ringing" in impulse tests. However, its counterparts, aliasing and imaging, are worse. This is part of a trade-off in the parameters of any filter: For a given filter, optimizing time domain response (decreasing "ringing") will make frequency response (aliasing and imaging) worse, and vice versa. Some designers try to make it easier to optimize both time domain and frequency response by oversampling (this allows a gentler filter slope to attain a desired frequency "cut" at the limits of the audio band, which in turn results in less ringing than a filter with a steeper slope).

 

While some people say we are not able to sense ringing, the fact that many people feel NOS DACs sound better may evidence their preference for as little ringing as possible. (To be absolutely fair, though, it could also be a liking for a "hotter," more "energetic" sound due to aliasing and imaging.)

[Jud]

There's quite a few release that takes 44.1khz and upsamples it and calls it hi-res and charge you more.

 

Yes. On the other hand, pretty much *every* release in 44.1kHz starts in the initial stage of the ADC in a format very similar to DSD, and is converted from there to the PCM format at some rate (anywhere from 352.8 to 44.1kHz; I don't know which is most common these days), and is perhaps converted a second time from higher rate PCM to 44.1kHz as well.

[ilok]

Yes, but this is half the story.

 

The type of gentle roll-off used as a filter by the Metrum is very good at eliminating "ringing" in impulse tests. However, its counterparts, aliasing and imaging, are worse. This is part of a trade-off in the parameters of any filter: For a given filter, optimizing time domain response (decreasing "ringing") will make frequency response (aliasing and imaging) worse, and vice versa. Some designers try to make it easier to optimize both time domain and frequency response by oversampling (this allows a gentler filter slope to attain a desired frequency "cut" at the limits of the audio band, which in turn results in less ringing than a filter with a steeper slope).

 

While some people say we are not able to sense ringing, the fact that many people feel NOS DACs sound better may evidence their preference for as little ringing as possible. (To be absolutely fair, though, it could also be a liking for a "hotter," more "energetic" sound due to aliasing and imaging.)

 

The argument is that the amp/speaker/ear/brain are all filters, and that once the NOS signal goes through those filters, it's back to a sine wave.

 

Edit: it's in the paper, the sound recorded back via a microphone is a sine wave.

 

I got a Metrum Pavanne DAC coming, so I will find out first hand. I currently got a 1bit super upsampling DAC!

[Jud]

The argument is that the amp/speaker/ear/brain are all filters, and that once the NOS signal goes through those filters, it's back to a sine wave.

 

I got a Metrum Pavanne DAC coming, so I will find out first hand. I currently got a 1bit super upsampling DAC!

 

Of course this same fact (that system components and ear/brain act as filters) is used by some people to argue that we can't hear ringing, so the Metrum's minimization of ringing does nothing.

 

Please realize that I am mentioning these things only to point out that different designers and listeners have different positions. (Not exactly shocking news, I know.) I haven't heard the Metrum, but several owners have posted in the CA forums that they like it a great deal. I wish you the same enjoyment.

[ilok]

Of course this same fact (that system components and ear/brain act as filters) is used by some people to argue that we can't hear ringing, so the Metrum's minimization of ringing does nothing.

 

Please realize that I am mentioning these things only to point out that different designers and listeners have different positions. (Not exactly shocking news, I know.) I haven't heard the Metrum, but several owners have posted in the CA forums that they like it a great deal. I wish you the same enjoyment.

 

I find theoretical discussions on internet forums to be worthless. Actual comparisons though I find them to be worth their weights in gold.

 

Singular review is another one that is not useful at all.

[Kimo]

I got a Metrum Pavanne DAC coming, so I will find out first hand. I currently got a 1bit super upsampling DAC!

 

I will be interested to read your review. I originally was going to go with the Pavane, but the Aqua became available first, so I gave it a try and went with it. Couldn't really see myself sitting around and comparing the two of them side by side.

 

Honestly, comparing DACs hasn't been that much fun. Still better than trying to do cables though.

[Kimo]

While some people say we are not able to sense ringing, the fact that many people feel NOS DACs sound better may evidence their preference for as little ringing as possible. (To be absolutely fair, though, it could also be a liking for a "hotter," more "energetic" sound due to aliasing and imaging.)

 

Sounds a little like the digital equivalent of a single ended triode amp...

[davide256]

I've been very pleased with the Metrum Octave vs other DAC's owned. It has synergy with tube amplification, producing what I call "bar of steel" tonal purity for midrange colors and a bottom to top seamlessness for detail and oomph. Its only negative is a sense of politeness on high frequency transients... you wouldn't call it airy. The ESS Sabre DAC's do highs better but tend to sound like a water color palette in the mid range vs. the oil color palette of the NOS Metrum Octave I.

[Miska]

I actually have quite a few hi-res recordings that sound worse than their 44.1khz counter part. We live in the digital dark ages...

 

Point is that there is very limited amount of content made using ADC conversion section running at 44.1k. Making good quality ADC where conversion section would be running at 44.1k is practically impossible because Nyquist frequency is too close to the audio band. For this reason all modern ADCs are oversampled and the ringing is specifically introduced when rate is reduced either inside oversampling ADC or later at mastering stage. Using DAC with half-band oversampling filter doesn't change this ringing or introduce new ringing. Using DAC with apodizing oversampling filter, the ringing introduced by ADC or mastering stage can be changed/removed. Using a NOS DAC naturally doesn't change the ringing, it is played as-is.

 

Using DSD end-to-end allows A/D and D/A conversions without intermediate sampling rate conversions and specifically allows to avoid rate down conversions which introduce ringing. If the target sampling rate is high enough that there is nothing for the down conversion filter to remove, then no ringing is introduced either, DXD (352.8k) is usually such rate.

[mordante]

Point is that there is very limited amount of content made using ADC conversion section running at 44.1k. Making good quality ADC where conversion section would be running at 44.1k is practically impossible because Nyquist frequency is too close to the audio band. For this reason all modern ADCs are oversampled and the ringing is specifically introduced when rate is reduced either inside oversampling ADC or later at mastering stage. Using DAC with half-band oversampling filter doesn't change this ringing or introduce new ringing. Using DAC with apodizing oversampling filter, the ringing introduced by ADC or mastering stage can be changed/removed. Using a NOS DAC naturally doesn't change the ringing, it is played as-is.

 

Using DSD end-to-end allows A/D and D/A conversions without intermediate sampling rate conversions and specifically allows to avoid rate down conversions which introduce ringing. If the target sampling rate is high enough that there is nothing for the down conversion filter to remove, then no ringing is introduced either, DXD (352.8k) is usually such rate.

 

To bad though that there is so little DSD content available. Even hires PCM music is almost impossible to find.

[Jud]

To bad though that there is so little DSD content available. Even hires PCM music is almost impossible to find.

 

Tell that to my bank account! Of course even if only a RedBook version of a recording is available, you can oversample and/or do sigma-delta modulation with software.

[mordante]

Tell that to my bank account! Of course even if only a RedBook version of a recording is available, you can oversample and/or do sigma-delta modulation with software.

 

The Native DSD site has less then 600 albums, HDtracks also has a very limited collection. Most of it is muzak like Norah Johns, Patrica Barber etc

[ilok]

I've been listening to a R2R NOS DAC for a few days now. And there is no comparison really. This is the real deal.

[ted_b]

I've been listening to a R2R NOS DAC for a few days now. And there is no comparison really. This is the real deal.

 

What DAC? I know you were dabbling with the Emotiva SSP but that is a DSD1796 oversampling DAC.

[ilok]

What DAC? I know you were dabbling with the Emotiva SSP but that is a DSD1796 oversampling DAC.

 

Metrum Pavane.

 

LOVE the sound.

[ted_b]

Metrum Pavane.

 

LOVE the sound.

 

Yes, I've heard great things.

[ilok]

Yes, I've heard great things.

 

If you are still on DS, you gotta audition it, there is really no comparison. Yesterday I understood why people say Metrum sounded analog. For the first time in close to 2 decades, I heard analog sound, and it was out of a all digital system.

[toddrhodes]

I'm finally hearing what my Aqua La Voce S2 R2R/Ladder DAC (NOS of course) can do. Calling it "natural" is almost not enough. It's liquid smooth, it paints an amazing, three dimensional picture and produces an almost romantic sound. And this is with metal and classic rock! But, don't mistake me, it can absolutely knock you out with aggression and dynamics. It's a great bit of kit. Compared to my previous Schiit Gungnir USB V2, it's no contest (and rightly it shouldn't be, La Voce is above Yggy for heaven's sakes).

[groovybassist]

+1 on R-2R NOS DACs

 

I'm using the Mojo Audio Mystique v2.0 and it just sounds like music. Doesn't matter whether I'm streaming internet radio or Redbook from NAS. I don't spend any time wondering about this or that - too busy tapping my foot and enjoying the music.

[YashN]

I'm finally hearing what my Aqua La Voce S2 R2R/Ladder DAC (NOS of course) can do. Calling it "natural" is almost not enough. It's liquid smooth, it paints an amazing, three dimensional picture and produces an almost romantic sound. And this is with metal and classic rock! But, don't mistake me, it can absolutely knock you out with aggression and dynamics. It's a great bit of kit. Compared to my previous Schiit Gungnir USB V2, it's no contest (and rightly it shouldn't be, La Voce is above Yggy for heaven's sakes).

 

Interesting to hear your feedback ilok and Todd. Sounds great indeed.

[toddrhodes]

Trust me, I'm happy to provide it - after all I get to listen to it To flesh out my config a little:

 

Server2012 R2 + AO GUI + Jriver + Jplay, Ultrastream

Dedicated audio room, 16-ish dB noise floor (yea, it's really quiet in here)

Room treatments for first and rear reflections, double-thick treatment behind my head, no bass traps

Barry Diament isolation under PC (in another room) and under the stack of equipment, consisting of: La Voce DAC, single ended RCA (DIY) out to Bel Canto Pre1 preamp, XLR (Mogami star quad) to Nuprime ST-10 amp.

DIY ScanSpeak speakers, two Bic America F12s (yes, the $180/per sub subs )

 

Whether it's a jazz trio, Rachmaninoff, or Pantera, the sound is incredible. Highly detailed, and a soundstage that doesn't feel like a 13 x 10 room should feel.

 

This DAC can easily articulate sound that moves left to right, inward and outward, and up and down - at the same time

[Norton]

I'm finally hearing what my Aqua La Voce S2 R2R/Ladder DAC (NOS of course) can do. Calling it "natural" is almost not enough. It's liquid smooth, it paints an amazing, three dimensional picture and produces an almost romantic sound. And this is with metal and classic rock! But, don't mistake me, it can absolutely knock you out with aggression and dynamics. It's a great bit of kit. Compared to my previous Schiit Gungnir USB V2, it's no contest (and rightly it shouldn't be, La Voce is above Yggy for heaven's sakes).

 

Which chip option did you go for?

[toddrhodes]

Hi Norton, I went with the standard dual Burr Brown option. I do like that I can change out boards for different sound if I am so inclined in the future though I have not inquired as to the cost of those boards...