DSD (SACD) vs PCM

[yves]

Jan 24, 2015 1:21:36 GMT -5 moko said:

hello keith,

first, i'm not sure about "the ringing is caused by the signal is band limited". the audio note CD-4.1x cd player which doesn't employ over sampling and digital filtering looks good on time domain :


even a cheap, $60 nos dac MUSE Mini TDA1543x4 does look good on time domain : archimago.blogspot.com/2013/02/measurements-muse-mini-tda1543x4-nos.html

here is another effect of different digital filters to impulse response : www.stereophile.com/content/dcs-vivaldi-digital-playback-system-measurements
(note that beside ringing, digital filter also affecting phase linearity like analog filter)

as for square waves which is in the frequency domain, i think most will agree that nos dac doesn't measure good on frequency domain, but they DO look good on square waves : www.dddac.com/dddac1794_test_specs.html

i'm not sure either about "the ringing is at frequencies you won't hear". the impulse response from ps audio dac is about 0.1 ms and the ringing is about 0.4 ms each way (before and after). 0.1 ms = 0.0001 s. with f = 1/T = 1/0.0001 = 10000 hz = 10 khz.

second, agree that all dacs use some filtering, wether it's digital or analog filtering. with EVERY kind of filter, we want the good thing to pass and the bad thing to go away. but unfortunately most of the time, the bad thing also pass. it means there are also some side effects. BOTH digital and analog filtering have its weakness. what i found does not make sense is applying that filter at high frequencies WOULD NOT affecting lower frequencies in the audible range. why ? because those filters are actually wide bandwith low pass filter. more steep filter will have more side effects. and like you said, even if the dac doesn't have filtering most pre-amps, power amps and speakers has their own filters. even our ears too ! www.metrum-acoustics.com/Design%20Philosophy%20Metrum%20Acoustics.pdf

third, i'm not saying that DSD avoids filtering. like you said before, in a pure DSD process, mixing and equalizing in DSD format is impossible. so in a true DSD playback, the filtering is done in the analog domain (not using digital filter). but unfortunately (just like in that weiss' white paper), some DSD players are not pure DSD like the ones who use Sabre ES9018 chip. they converted DSD to PCM first then applying digital filter which make it not a pure DSD and lossy conversion.

The Sabre ES9018 chip does *not* convert DSD to PCM first. What it does do is it uses a Delta Sigma Modulator that is 6 bits wide, and the reason why it does that is because of the simple fact a Multi-Bit Modulator (MBM) can achieve greater accuracy than a 1-bit modulator can, *regardless* of whether the DAC is playing PCM or DSD. So the industry has almost completely moved away from 1-bit modulators for playback of both PCM *and* DSD, i.e. almost every modern DSD capable DAC uses filters in order to actually, contrary to popular oldschool "DSD belief" of course, *improve* accuracy.

[Deleted]

From the January 2015 issue of UK Hi Fi News:  while reviewing  the QB9-DSD DAC from Colorado's Ayre they include a link to a piece by the company's founder and designer Charlie Nansen lamenting the problems with DSD and stating why he wasn't keen on it at all (perversely the company is producing expensive DACs for DSD playback all the same...go figure). Anyway, the history of SACD, the demise of DVD audio and the reasons he thinks DSD was marketed is worth the read IMO.

The site also provides some free, downloadable 'needle drops' of both DSD and PCM versions of files for comparison.

The article here at:
www.ayre.com/insights_dsdvspcm.htm


BTW - Ayre developed the DAC chip for the current Pono player.

[plm]

Jan 30, 2015 15:51:49 GMT -5 @blooloo said:

BTW - Ayre developed the DAC chip for the current Pono player.

Are you sure? Ayre designed the electronics for the Pono, but the DAC is an ESS Sabre 9018.

[Deleted]

Jan 31, 2015 13:44:27 GMT -5 plm said:

Jan 30, 2015 15:51:49 GMT -5 @blooloo said:

BTW - Ayre developed the DAC chip for the current Pono player.

Are you sure? Ayre designed the electronics for the Pono, but the DAC is an ESS Sabre 9018.

You're right - sorry, was a late night posting  ,

I should have said they were called in to develop the electronics for Pono after Meridian opted out...

[plm]

I wish Meridian had done the electronics. I have one of these sat idle on my coffee table, and despite Ayre being involved (and having a great reputation) it's a real let-down. It's in a whole different ballpark to my other Sabre 9018 DACs. I'd go so far as to say it's unpleasant to listen to, in fact.

[Deleted]

Feb 1, 2015 15:25:52 GMT -5 plm said:

I wish Meridian had done the electronics. I have one of these sat idle on my coffee table, and despite Ayre being involved (and having a great reputation) it's a real let-down. It's in a whole different ballpark to my other Sabre 9018 DACs. I'd go so far as to say it's unpleasant to listen to, in fact.

Interesting you say that. I had my doubts based on how the development was proceeding initially, however my daughter's partner loves his and he's a muso and sound engineer (I might add he is listening through high quality headphones as I know his stereo is the most basic of basics). I have not had a chance to listen to one yet myself but will do so in a few weeks time.

I'd be interested to know what aspects you find unpleasant. Thanks.

[plm]

The bass seems loose and poorly-controlled, and it seems to have a rising frequency response that makes it fatiguing to listen to. Rides, in particular, don't sound natural. I've tried listening to two of these (that both sounded different, but similarly poor, which suggests that QC isn't as hot as it could be), through the balanced and single-ended outputs into my hifi, and balanced and single-ended into a pair of Sennheiser HD600s, and single-ended into my Ultimate Ears UE10pros.

My pal, who is a studio engineer, excitedly brought his over with a pair of balanced cables to put it up against my W4S DAC-2DSDse in my hifi, and only managed to get a few bars in before he let out a rather deflated, "Oh."

[KeithL]

A lot of this simply highlights the fact that the DAC CHIP is only a small part of what makes up the sound of a DAC (the audio component). Unfortunately, in our modern world, where "brand recognition" is so important, people have come to believe that having a "Sabre DAC" means that a product will automatically sound good, which is obviously not the case - although that assumption sure helps ESS to sell more Sabre chips  . (The original DragonFly used a Sabre chip, and I never especially liked the way it sounded either, and it sure didn't sound anywhere near as good as my W4S, or several other Sabre-based products I've heard.)

I haven't heard the Pono - but I do have a W4S DAC-2 (the original non-DSD one) and can attest that W4S's implementation of the Sabre DAC sounds VERY good.

Feb 6, 2015 11:49:50 GMT -5 plm said:

The bass seems loose and poorly-controlled, and it seems to have a rising frequency response that makes it fatiguing to listen to. Rides, in particular, don't sound natural. I've tried listening to two of these (that both sounded different, but similarly poor, which suggests that QC isn't as hot as it could be), through the balanced and single-ended outputs into my hifi, and balanced and single-ended into a pair of Sennheiser HD600s, and single-ended into my Ultimate Ears UE10pros.

My pal, who is a studio engineer, excitedly brought his over with a pair of balanced cables to put it up against my W4S DAC-2DSDse in my hifi, and only managed to get a few bars in before he let out a rather deflated, "Oh."

[plm]

Keith

Good points, and one thing also to note is that the Sabre 9018 is notoriously difficult to get right. It's very finicky with board layout and power supplies. Although you'd like to think that with Ayre's reputation they'd be able to get it right.

And if you use the USB input on your W4S, try to get a listen to a DSD version, which guarantees the newer (driverless) USB interface. It's a big difference over the older one. I actually found myself buying a second one when an 'se' came up at a good price!

[emovac]

Feb 6, 2015 11:49:50 GMT -5 plm said:

The bass seems loose and poorly-controlled, and it seems to have a rising frequency response that makes it fatiguing to listen to. Rides, in particular, don't sound natural. I've tried listening to two of these (that both sounded different, but similarly poor, which suggests that QC isn't as hot as it could be), through the balanced and single-ended outputs into my hifi, and balanced and single-ended into a pair of Sennheiser HD600s, and single-ended into my Ultimate Ears UE10pros.

My pal, who is a studio engineer, excitedly brought his over with a pair of balanced cables to put it up against my W4S DAC-2DSDse in my hifi, and only managed to get a few bars in before he let out a rather deflated, "Oh."

Sweet. I also have the base DAC-2, and am thinking of making the jump to the DSDse model. Is yours an upgraded unit, or DSDse off the shelf? if yours was upgraded, can you can weigh in on how much better you like it.

[plm]

Feb 7, 2015 5:38:30 GMT -5 emovac said:

Sweet. I also have the base DAC-2, and am thinking of making the jump to the DSDse model. Is yours an upgraded unit, or DSDse off the shelf? if yours was upgraded, can you can weigh in on how much better you like it.

So, I have two. I have a DAC-2DSD with the femto grade clock, and a DAC-2DSDse. I've heard the DAC-2, but never had it to compare directly against my DSDs. There isn't a world of difference between the DSD and the DSDse, but then my DSD is pretty close to the se spec already. It just misses the Vishay resistors, the oLED display (to negate the need for the fluorescent inverter), and the discrete regulators.

My view is that the biggest bang for the buck is the DSD with the clock upgrade. I originally thought I'd sell mine when I picked up my se for a great price used, but it's still such an awesome DAC that I'm keeping it. I think it's unlikely I'll take it up to se spec as I'm happy with it as it is.

[emovac]

Thanks. I thought about just adding the femto clock for $275, but will hold out hope W4S will do another black friday deal at the end of the year and I'd pick up a new DSDse. Keeping my eyes on the used market too for a DSDse that was sold as new, since many of the upgraded versions (returned for the upgrade) of the DAC-2 are 3-4 years old. The base DAC-2 is a great unit and I can afford to be patient replacing it.

Thanks again for the info on your DACs.