Eliminating jitter "completely" - Benchmark DAC1 approach

[PHEONIX]

BENCHMARK DAC1

Hello

There seems to be a mistake here that needs correction, the DAC1 uses 28.322Mhz clock and not 25Mhz. If technical things are to be discussed we should facts straight.

Benchmark DAC1 should be looked at as a whole thing and not reduced just to its bare bone chips. This unit is very competently put together unit, with a good PCB design. Thats why it works well.

Regards
Arhur Rappos

 

[ThorstenL]

Re: BENCHMARK DAC1

Konnichiwa,

There seems to be a mistake here that needs correction, the DAC1 uses 28.322Mhz clock and not 25Mhz. If technical things are to be discussed we should facts straight.

That would be good. Now, IF the DAC1 used a 28.322MHz Crystal the ASRC and DAC would work at an integer divisor of either 128, 256 or 384 giving either 221.2656KHz, 110.6328KHz or 73.7552KHz. The one frequency it could NOT work at, with a 28.322MHz X-Tal is the claimed (in Benchmarks Literature) constant 97.65625 kHz.

So, it would indeed be good that if wish to discuss technical things we should get our facts straight. Either Benchmark has theirs wrong or you yours.

Benchmark DAC1 should be looked at as a whole thing and not reduced just to its bare bone chips.

I believe that is what was done here, to consider the whole operation and interaction of the various sections of the DAC and the result as a whole.

Sayonara

 

[PHEONIX]

DAC1

Hello Kuei Yang Wang

I have in my possesion a DAC1, I just read off the frequency written on the clock , which reads 28.322Mhz (clock frequency) ECS-2100(MANUFACTURES series no).

Regards
Arthur Rappos.

 

[PHEONIX]

Re: Re: Eliminating jitter "completely" - Benchmark DAC1 approach

Hello Kuei Yang Wang



"The DAC does not accept 192KHz input."

The DAC1 does accept 192Khz input it then down converts this to 96Khz.



Regards
Arthur

 

[ThorstenL]

Re: Re: Re: Eliminating jitter "completely" - Benchmark DAC1 approach

Konnichiwa,

I have in my possesion a DAC1, I just read off the frequency written on the clock , which reads 28.322Mhz (clock frequency) ECS-2100(MANUFACTURES series no).

Then the in your posession DAC1 does not operate according to the claims of Benchmark Media.

I find it interesting insofar as this would shift the sample rate of the resampled signal to > 110KHz or about 14KHz above 96KHz in which case any claims of avoiding problems in the transtition would make marginally more sense.

"The DAC does not accept 192KHz input."

The DAC1 does accept 192Khz input it then down converts this to 96Khz.

Interesting. I found no reference in Benchmarks materials to any sample rate above 96KHz, must have overlooked it or it is another change in production compared to what the promo material claims.

Sayonara

 

[rfbrw]

Re: Re: Re: Re: Eliminating jitter "completely" - Benchmark DAC1 approach

Konnichiwa,

Interesting. I found no reference in Benchmarks materials to any sample rate above 96KHz, must have overlooked it
Sayonara

You mean you missed the description of the DAC1 as "a two-channel, 24-bit, 192-kHz Digital-to-Analog audio converter" as stated on the cut sheet, in the manual and on the website? Well, no one is perfect.

http://www.benchmarkmedia.com/digital/dac1/index.html

 

[ThorstenL]

Re: Re: Re: Re: Re: Eliminating jitter "completely" - Benchmark DAC1 approach

Konnichiwa,

You mean you missed the description of the DAC1 as "a two-channel, 24-bit, 192-kHz Digital-to-Analog audio converter" as stated on the cut sheet, in the manual and on the website? Well, no one is perfect.
http://www.benchmarkmedia.com/digital/dac1/index.html

No, I noted the DAC1 as "DAC1 - Two Channel 24-bit, 96-kHz D/A Converter " as stated on Benchmarks website:

http://www.benchmarkmedia.com/digital/

and failed to observe any explicitly different statement which is only in the part of the blurp I never read at:

http://www.benchmarkmedia.com/digital/dac1/index.html

All I noticed where claims of using a 192KHz capable DAC Chip, which however does not imply acceptance of a 192KHz fs S/P-DIF or AES/EBU Datastream.

Sayonara

 

[00940]

http://www6.head-fi.org/forums/showthread.php?t=78848&page=7&pp=15&highlight=benchmark

You can have the comments of a Benchmark engineer in there (starting post99). He notably justifies the use of the ne5534 against opa134 or the frequency picked.

Btw, the old models are 24bit/96khz, the new ones 24/192. The old ones can be upgraded.

 

[atticus]

Just an FYI, but I worked in the marketing department at Benchmark when the DAC1 was released in 2002 and there was no intended misinformation given. The engineering staff was simply trying to make the most accurate dac they could in the price range and we (there were two of us at the time) just tried to tell people about it. Thanks.