DS - Stereophile A+!


#1

Congratulations Paul and Ted. Not that it really means anything (we already know how good the DS is), but a lot of the audiophiley public goes by stuff like this.


#2

Where did you see this?

Thanks,


#3

Thanks Tony!!


#4
tony22 said . . . a lot of the audiophiley public goes by stuff like this.
They do, and I suspect this listing will have greater impact on many than Art Dudley's review itself.

As an aside, it was clear to me from his review this is where the DS would land. Interestingly, a number here and elsewhere opined his review was an insufficient rave.


#5

They gave us an A+ rating in the recommended components list for DACS.


#6

I couldn’t see it under the A+ Dacs…(?)


#7

It’s not yet online. The newest issue of the print magazine has it in there. Hopefully they’ll update the webpage soon.


#8

Yes, for once I got my copy of Stereophile before anyone else!21_gif

Paul, I have a suggestion that I hope you and Ted may consider. As Ted has found the low bit order bug that caused some of those “classic measurement” anomalies and fixed it, maybe for RMAF you could have prepared a visual of the results of measurements showing…

It just occurred to me as I’m writing that you may not want to do that. It would be with unreleased FW - which I suspect is something you don’t want to have to harangue over at the show. It’s just that the show is coming right on the heels of the review and now the Rec Equip rating. It would sure be nice to just have the hammer on hand to put this to rest with hundreds (thousands!) of people and a gaggle of audio writers coming by. You’d think the sound would be enough.facepalm-smiley-emoticon_gif

OTOH if there is something in the works in a pre-beta stage that incorporates this fix, IMO that would clear you to be justified in showing any updated measurements if you chose to do so. Tricky. I’m not sure what decision I’d make myself now that I’m seeing what I wrote.


#9

Isn’t this remedial fix adressing just one of the complaints/critisism from Atkinson?


#10

Well, we’re working on it. As always. Takes time. Let me see where we are in firmware. Maybe there’s something in the works. 65_gif


#11

Maybe even such comments like this could be improved:

http://www.stereo.net.au/forums/index.php?/topic/56913-money-no-object-digital-front-end/?p=1188228


#12

Now where is @alrainbow ? That comment related to his DACs.


#13
Frode said Maybe even such comments like this could be improved:

http://www.stereo.net.au/forums/index.php?/topic/56913-money-no-object-digital-front-end/?p=1188228

I wouldn't pay too much attention to the rubbish that appears in that SNA forum, it's poisoned by vitriol, hidden agendas and plain ignorance. Ordinarily I'd jump in there and have a bit to say in response, but I can't since SNA Admin banned me from posting for doing just that in the past. SNA members know how to contact me, and are always welcome to come and listen to my DirectStream and form their own conclusions (as far as I know mine is the only example in this part of the world).

DirectStream is an outstanding piece, listening to mine it is impossible to come to any other conclusion.


#14

I’m curious whether the observations made by JA in the measurements section of the review, particularly: “…somewhat bothered by its ultimate lack of resolution with data capable of higher-than-CD resolution” and “…poor linearity at lower frequencies”, and “…anomalous results when I tested the PS Audio DirectStream’s rejection of wordclock jitter”, and “…things didn’t look so good, however, when I performed a wider-band spectral analysis with the PS Audio processing dithered data representing a 1kHz tone at –90dBFS with 16-bit and 24-bit data”.

Are all these findings peculiar to the v1.1.4 firmware; perhaps these have been addressed in subsequent firmwares?

Not-withstanding, the A+ is an excellent result and would certainly put DS on the purchasing radar of many potential customers, particularly given the current buying incentive in the US market (which has been talked about elsewhere on the forum).


#15

(Parenthetically JA was kind enough to do all of his tests both with the original software that Stereophile received and with the update that we all are used to now: there were no significant differences.)

There are several things going on here. JA uses the word resolution when he instead should be talking about the effects of the noise floor. The DS (and other DSD based DACs, for example, the Playback Designs devices) have a higher noise floor than PCM DACs and this violates some assumptions that we all are used to making when interpreting the tests designed for PCM DACs. The noise floor doesn’t lessen resolution: JA even has FFTs of signals that are lower than his claimed resolution… I think it’s almost a no brainer that if he measures signals at -90, -100, -110, -120dBFS that the resolution must be better than his claim of 17 bits (-102dBFS.) We couldn’t get him to rephrase his results taking into account the noise floor…

The same problem confounds some other tests, e.g. the noise floor obscures the results of the jitter test he uses. On the other hand he explicitly states that the part he does see of his jitter test is very narrow (which is a good thing.) The test he uses is designed to measure the transference of jitter from the digital inputs to the analog output. The DS excels here anyway.

Embarrassingly for me JA did measure a low level non-linearity which turned out to be a software bug: I found a fix the day we found out about his measurements, but more recently I’ve found a more general fix and am thankful to JA for pointing the bug out. You’ll hear about the effects of the more general fix when it’s released. Either of the fixes give clean FFTs of 1k Sines at -90dBFS … -120dBFS signals, dithered or undithered.


#16

If Atkinson won’t repeat his tests on the next FW upgrade, is this something that PS Audio (or a 3rd. party consultant) would consider doing, followed by a report on the matter?


#17

Once we’re sure what we’ll be releasing we could produce some before and after tests (since we may not be using his exact tests.) My system has more background noise (USB spikes at 8K, AC hum, etc.) but the before and after are still clear.


#18

Ok, I think you have to produce something that is ‘fool-proof’ and unambigous to not put gasolin onto the fire. If you say ‘don’t get hung up with this insignificant detail’ it is exactly what the measurement-mafia would do. They would just relentlessly try to find something to criticise to create doubts. It is much more important for them to justify their arguments than to contribute to advances in HIFI.


#19

Yep, that’s exactly the reservations that I have. We still have to think about it.


#20

There’s a guy on AA who remarked in a thread that mentioned the odd measurements that he would not buy one. The context of the messages made it seem like the measurements were what caused him to reach that conclusion.

Folks like that are out there.