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Review of the Audio-gd DAC-19 DSP & C2 amp - The ACSS connection - Page 2

post #16 of 981
Very nice review, Slim.
post #17 of 981
WOW...what a detailed review.. Makes me want to buy one of the Audio-GD's DACs
post #18 of 981
You amaze me Slim...

Quote:
Originally Posted by slim.a View Post
At one point I was trying different upsampling rates while playing back. And after that I noticed that there was an inversion of channels in the DSP-1. After shutting down the DAC19dsp and restarting it, there was no channel inversion and I couldn’t reproduce the bug.
It is not inversion... it is DSP-1 buffer corruption. Nothing to worry about, it happens sometimes when changing sample rates: sound suddenly "goes left" or something like that. Off/on (restart) fixes that.
Quote:
Originally Posted by slim.a View Post
I have also been meaning to try different oversampling settings on the DSP-1 and especially try the NOS mode for a longer period (I only tried for a few minutes to form a definitive opinion on it).
Plenty of things to try there. But from my experiences - NOS is quite dull in comparison to OS: the highs and low level details just "go for a break" in NOS mode and aren't there. Much more interesting effects in stopband attenuation settings (space vs. focus) and definitely in dithering: it seems that enabled dithering (default setting) "rounds the edges" which is pleasant, but with no dithering the sound is more "direct" and detailed. YMMV.

Keep on going Slim.
post #19 of 981
Very entertaining read!
post #20 of 981
Thread Starter 
Thanks everyone for you nice comments on the review! I very much appreciate it
post #21 of 981
Thread Starter 
Quote:
Originally Posted by bearbb View Post
very good review. I really want to get a DAC19. I am using musiland md10 + MiniWatt N3, I think it will be a big improvement.

slim.a, can dac19 comparable to more expensive dacs like benmark dac1 or even Weiss DAC2?
Quote:
Originally Posted by bearbb View Post
I think I got the answer from this blog. Audio-gd DAC-19Mk3; DAC-19 (MkIV) « ravenda's blog This blogger is even using dac19mk3 only.
I think that if we look a the cost of parts alone, the dac19dsp is far more expensive to make than something like the Benchmark DAC1.
Many people who have tried the older DAC19mk3 found it better than the benchmark and PS Audio DLIII ...

Personally, since I listened to the dac19mk3, I am not able to enjoy sigma-delta based DACs and CD Players regardless of the price. The more resolving sigma-delta DACs are, the more annoying they are to my ears. So far, and according to my experience, the only DAC chip that offer both detail and naturalness of tone is the PCM1704. So my answer will be biased, if you are looking for the most natural representation, the dac19dsp will probably do a better job than some "more expensive" DACs.

Quote:
Originally Posted by Eagle Eye View Post
You have put together a very comprehensive review and it deserves our thanks. Your review was very easy to read and follow. Will be awaiting the results of the other ACSS cables. I am patiently patiently awaiting the arrival of the Reference 5, LOL.
I will defintely keep you updated on the "ugpraded" ACSS cables.
However, if I remember correctly, Pricklely Peete already made some custom ACSS cables to connect his ref-1 to the Phoenix, so he probably might give us some information on what to expect on the subject.


Quote:
Originally Posted by oqvist View Post
thanks for the review. Must have taken a month to write ... would you say hiface is better then using spdif out of better soundcards like Elite Pro or Essence ST?

Essence ST didn´t have bit perfect when I had it but the Elite Pro have native support for it in XP anyway.
I think I have read some people (on the usb to spdif shoot out thread and the m2tech hiface thread) comparing the Hiface vs. soundcards such as the Elite Pro and Essence, and it seemed that the Hiface had the upperhand. And once you get the hiface, you can always get it modded later.


Quote:
Originally Posted by sk3383 View Post
@slim.a

How would you rate the DAC-19DSP against the DAC-19MK3 PMD100?

Do you still own a DAC-19MK3 for direct comparisn?
I have already sold my dac19mk3. However, I have kept a lot of notes during the last months and I have compared it extensively to the other DACs including the FUN that serve as a base line.

The dac19mk3 was like 2 DACs in one. With the PMD100, it is was warm and analog sounding. With the DF1704, it was fast and analytical. Both digital filters had distinct sound signatures. The DSP-1 falls somewhere in the middle retaining the accuracy of tone of the PMD100 and adding the speed and clarity of the message of the DF1704.

So while I don't have the dac19mk3 (w/PMD100) on hand to make a direct comparison, the differences in "personalities" are big enough that they are easily described without extensive A/B testing. If you read my review of the dac19mk3 (here), you will see that I have described the overall sound differently.


Quote:
Originally Posted by TheDuke990 View Post
I'm a little bit confused. You wrote DAC-19 DSP and PCM1704 ? I thought the DAC19DSP is the version with DSP1 digital processor and the the PCM1704 version is called DAC-19 DF.

Sorry in advance when I'm wrong ;-).

н¨ÍøÒ³ 1
I understand that the names can be a little bit confusing at time. There are 2 things that use the 1704 digits: the digital filter and the dac chip.

The digital filter: you have the the choice between 2 of them: the DF1704 (for the dac19DF) and the DSP-1 (for the DAC19 DSP).

The dac chip: both the dac19df and the dac19dsp use the PCM1704uk chip.

The reason that both the digital filter and the dac chip share the same 1704 number is simple: the PCM1704 needs an external digital filter to function, and Burr Brown/TI made 2 digital filters specifically with the PCM1704 in mind: the DF1704 and DF1706.

So to sump up, in the dac19, you can either have:
1. DF1704 + 2xPCM1704uk
2. DSP-1 + 2xPCM1704uk


Quote:
Originally Posted by gevorg View Post
Very good review, slim.a!



A bit skeptical, but still interested in see what you have to say about these tweaks. Particularly, which tweaks do you think make the most difference, and which ones are "icing on the cake". The method you use for comparison is also interesting to know.
I will talk more about the "tweaks" on a follow-up and will try to assess which are the most important ones.


Quote:
Originally Posted by FauDrei View Post
You amaze me Slim...


It is not inversion... it is DSP-1 buffer corruption. Nothing to worry about, it happens sometimes when changing sample rates: sound suddenly "goes left" or something like that. Off/on (restart) fixes that.

Plenty of things to try there. But from my experiences - NOS is quite dull in comparison to OS: the highs and low level details just "go for a break" in NOS mode and aren't there. Much more interesting effects in stopband attenuation settings (space vs. focus) and definitely in dithering: it seems that enabled dithering (default setting) "rounds the edges" which is pleasant, but with no dithering the sound is more "direct" and detailed. YMMV.

Keep on going Slim.
Thanks for the info on the dithering and stop band settings. I only tried quickly the NOS setting and wasn't too convince about it. I even tried native 24/96 on the NOS and it wasn't very pleasing to the ears.

But with all the oversampling, dithering, stopband settings, it seems that there a lot more to try
post #22 of 981
Quote:
Originally Posted by squall343 View Post
If i am not wrong both DSP and DF use 1704UK
But DSP uses DSP1 digital processor while DF uses DF1704

Quote:
Originally Posted by slim.a View Post
I understand that the names can be a little bit confusing at time. There are 2 things that use the 1704 digits: the digital filter and the dac chip.

The digital filter: you have the the choice between 2 of them: the DF1704 (for the dac19DF) and the DSP-1 (for the DAC19 DSP).

The dac chip: both the dac19df and the dac19dsp use the PCM1704uk chip.

The reason that both the digital filter and the dac chip share the same 1704 number is simple: the PCM1704 needs an external digital filter to function, and Burr Brown/TI made 2 digital filters specifically with the PCM1704 in mind: the DF1704 and DF1706.

So to sump up, in the dac19, you can either have:
1. DF1704 + 2xPCM1704uk
2. DSP-1 + 2xPCM1704uk
Ah okay. Thanks !
post #23 of 981
"The PMD100 was a rare and discontinued HDCD capable digital filter that was limited to 24/55 (but experiment showed it could go as high as 24/88)."

Actually at 24/88.2 the PMD100 plays but it is skipping every other sample, so you are just getting 44.1. It is also truncating to 20 bit.

Great review, I have been preaching the virtues of R2R Dacs for years. One day you need to hear a well implemented AD1862.
post #24 of 981
I just ordered a dac19dsp, can't wait to hear how it sounds :-)
post #25 of 981
Thread Starter 
Quote:
Originally Posted by regal View Post
"The PMD100 was a rare and discontinued HDCD capable digital filter that was limited to 24/55 (but experiment showed it could go as high as 24/88)."

Actually at 24/88.2 the PMD100 plays but it is skipping every other sample, so you are just getting 44.1. It is also truncating to 20 bit.

Great review, I have been preaching the virtues of R2R Dacs for years. One day you need to hear a well implemented AD1862.
Thanks for the clarfication on the 24/88 setting on the PMD100. At the time I had the dac19mk3, I couldn't figure out how and why it worked at 24/88.2.

Concerning the AD1862, it might be difficult to listen to one. I guess I should probably look into the vintage DACs?
It is weird anywyay, that even after spending years in developping sigma-delta dacs, dac makers still cannot make them sound as good as the R2R made in the late 90s.
I hope also to try some day a custom made R2R/multibit dac chip made by Lavry or DCS. They are supposed to sound even better the pcm1704...

Quote:
Originally Posted by bearbb View Post
I just ordered a dac19dsp, can't wait to hear how it sounds :-)
Let us know how you like the sound once you get it
post #26 of 981
fantastic review Slim.a, i always enjoy reading your incredibly well written material

my only question would be one that you probably cannot answer. Im trying to pick out a desktop amp to use with my jh-13's, which are a very sensitive iem, and im wondering if the c2 + dac19DSP would hiss with them? im also contemplating the Meier Concerto because of its ridiculously high SNR value of close to 135db. Any insight into the SNR of the combo would be greatly appreciated
post #27 of 981
Thread Starter 
Quote:
Originally Posted by SoupRKnowva View Post
fantastic review Slim.a, i always enjoy reading your incredibly well written material

my only question would be one that you probably cannot answer. Im trying to pick out a desktop amp to use with my jh-13's, which are a very sensitive iem, and im wondering if the c2 + dac19DSP would hiss with them? im also contemplating the Meier Concerto because of its ridiculously high SNR value of close to 135db. Any insight into the SNR of the combo would be greatly appreciated
Thanks for the comments on the review

Concerning the c2+dac19dsp, it is dead quiet with the Sennheiser hd-650 even when turning the volume to the maximum. If the led weren't lit, I couldn't tell if the units were on or off.

With the far more sensitive cx300, I start hearing the noise floor when I got past 2-3 o'clock. However even with the quietest classical albums I have, I can't go past 10 or 11 with it (and I can listen to the music very loud sometimes).

I measured the SNR of the dac19dsp+c2 at 106dB. But I am not sure my measuring equipment was good enough. So what I can say is that the combination has a SNR better or equal to 106db.

Concerning the 135db figure of the concerto, I think you might be confusing the noise floor showed by the graph (the one in the 6moons article maybe?) and the actual weighted SNR. When I measured the dac19dsp+c2, the noise floor was at the 140db level, but the weighted SNR was 106db (see the attached picture).
My guess is that the Concerto has a SNR between 100db and 110db, but defintely not 135db (which would make it by far the best measuring preamp in the world )

When looking at the SNR of a "regular" voltage preamp, keep in mind that many manufacturers do it in a best case scenario: The SNR at 1v will be different than the SNR at 10v ...
Stereophile does a good job by measuring all the preamps at 1v with the same methodology.

Overall, while I think that you probably won't have noise issues with the c2, you might however encounter another problem: there is a slight channel imbalance when you go close to the maximum attenuation. So in your specific case, you might want to contact Kingwa about the jh-13 and see if he can make you a custom unit with a volume pot that has a better usable range for high sensitivity headphones such as yours.

ps: the slight rise of noise floor in the left channel is coming from my emu 0404 usb, (that is one of the reasons I didn't post the whole results).
LL
post #28 of 981
Quote:
Originally Posted by slim.a View Post
Thanks for the comments on the review

Concerning the c2+dac19dsp, it is dead quiet with the Sennheiser hd-650 even when turning the volume to the maximum. If the led weren't lit, I couldn't tell if the units were on or off.

With the far more sensitive cx300, I start hearing the noise floor when I got past 2-3 o'clock. However even with the quietest classical albums I have, I can't go past 10 or 11 with it (and I can listen to the music very loud sometimes).

I measured the SNR of the dac19dsp+c2 at 106dB. But I am not sure my measuring equipment was good enough. So what I can say is that the combination has a SNR better or equal to 106db.

Concerning the 135db figure of the concerto, I think you might be confusing the noise floor showed by the graph (the one in the 6moons article maybe?) and the actual weighted SNR. When I measured the dac19dsp+c2, the noise floor was at the 140db level, but the weighted SNR was 106db (see the attached picture).
My guess is that the Concerto has a SNR between 100db and 110db, but defintely not 135db (which would make it by far the best measuring preamp in the world )

When looking at the SNR of a "regular" voltage preamp, keep in mind that many manufacturers do it in a best case scenario: The SNR at 1v will be different than the SNR at 10v ...
Stereophile does a good job by measuring all the preamps at 1v with the same methodology.

Overall, while I think that you probably won't have noise issues with the c2, you might however encounter another problem: there is a slight channel imbalance when you go close to the maximum attenuation. So in your specific case, you might want to contact Kingwa about the jh-13 and see if he can make you a custom unit with a volume pot that has a better usable range for high sensitivity headphones such as yours.

ps: the slight rise of noise floor in the left channel is coming from my emu 0404 usb, (that is one of the reasons I didn't post the whole results).
Thanks for for the detailed reply slim.a. i didnt realize there were two methods for measuring snr like that it seems that the c2 would be at least as quiet as the concerto if not more quiet. And also thanks for the tip to ask kingwa if a better volume control could be incorporated into the c2 ill have to look into that when the time comes.
post #29 of 981
Quote:
Originally Posted by SoupRKnowva View Post
And also thanks for the tip to ask kingwa if a better volume control could be incorporated into the c2 ill have to look into that when the time comes.
Kingwa does have some stepped (break before make) attenuators but they pop/click when you change the volume, so he's stopped using them in the C2. But that was a loong time ago, actually i think it was the previous C2 model.

Anyway, you could always get a goldpoint/dact/tkd attenuator and swap it in. Those will give you spot on channel tracking at all volume levels, superb attenuation with no pop/clicking between levels and a nice feel. They are expensive, though
post #30 of 981
Quote:
Originally Posted by SoupRKnowva View Post
Thanks for for the detailed reply slim.a. i didnt realize there were two methods for measuring snr like that it seems that the c2 would be at least as quiet as the concerto if not more quiet. And also thanks for the tip to ask kingwa if a better volume control could be incorporated into the c2 ill have to look into that when the time comes.
I wouldn't agree with slim.a on the post for noise floor, the C-2 is not the quietest I've heard,with my Grado 325is even with no DAC connected the complete darkness disappears at about 2'o clock and same on high gain, I do have cx300 will test and advise later.
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