Audio Research DAC7 Shows Its Face

You're 100% right about the low level of buzz on the DAC7. <br />

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I'm on the top of the list to get the new Ayre USB DAC in for review. I hope to have info soon.

Im using the dac 7 at the moment. An also using a big ben clock that i took out of one of my recording studios today. Its all going well. Driver showed up an all is playing. Its a real smooth dac, Usb is i think almost as good as the spidf signal. Ive been going through alot of dacs lately. Ive used benchmark in my system too with great results. Im thinking of grabing the on of the apogee rosettas that i have and trying that tomarrow. I value this site alot.

Im going to get intouch with apogee tomarrow an ask if i ca get the firewire 400 card for the big ben i think at least i can get itunes in to the big ben then out to what ever dac i want to use. I really need to figure this out. I really want to add dacs for sever play back in each control room at studios. We do alot of cross reference with other mixes by other artists when we mix. Ive looked at alot of solutions an its hard to commit on what ive been hearing . Tho the dac 7 is growing on me..thanks for any input i can get...

According to this review:<br />

http://www.soundstagenetwork.com/ultraaudio.com/equipment/arc_dac7.htm<br />

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<ol><cite><br />

...ARC’s Dave Gordon told me that the DAC7 operates in "asynchronous mode"; i.e., a clock within the DAC controls the transfer rate of the digital signal. In a typical system, the timing of the digital-signal transfer rate is dictated by the computer, in what’s called adaptive mode. A USB connection via a computer is not ideal for this task, partly because of the number of functions a computer’s processor is required to simultaneously perform. When the processor in the computer is overtaxed, the digital stream ostensibly suffers, and the timing of the audio delivery won’t be perfect.<br />

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From what Gordon told me, the benefit of an asynchronous-mode DAC is less digital jitter (i.e., fewer timing errors within the digital stream itself), which, on paper, should result in better sound. ARC goes this one better, however: Once the digital data are inside the DAC7, they’re buffered (stored in memory), then re-clocked by an ultra-accurate second clock, before being fed to the DAC itself....<br />

</cite></ol><br />

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This suggests that it works in a manner similar to the Ayre and Wavelength products. Exciting!<br />

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Chris, are you still going to review this DAC?

Gang,<br />

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I contacted Doug, Marc and Jeff this morning... anyone can read the data sheet for the PCM2902 and realize that the only Asynchronous USB is for recording not for playback.<br />

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http://focus.ti.com/docs/prod/folders/print/pcm2902b.html<br />

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We have talked to Dave Gordon about this practice. I am not sure why he keeps telling people something their device does not do.<br />

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Chris I can send you the USB Prober application for mac development. It will show everything any device will do on a mac in full detail.<br />

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Thanks<br />

Gordon

Gordon, thanks for the reply. Who are Doug, Marc and Jeff? Jeff Fritz, the reviewer?<br />

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I'm really torn between the Ayre QB-9 and the ARC DAC7. I find the lack of technical details from ARC frustrating, and really appreciate the Information you and Charles Hansen have made available. I'll be honest -- i'm a bit of a gear-head and the technology and engineering behind a product is as important to me as the sound quality.

Phunge,<br />

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Doug and Marc own the Sound Stage network and Jeff is of course the writer involved in the review.<br />

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I am a little confused as to why you would consider between these two dacs. They are polar opposites as far as their direction.<br />

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On one hand you have the QB9 which is solid state USB with minimum phase filters. Then you have the DAC7 which is tube, upsampling all SPDIF (as the USB is actually a USB->SPDIF converter). The thought process between the two could not be further apart.<br />

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People if I can say anything about helping you people out with audio.... go to your dealer, try this stuff out.<br />

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Thanks<br />

Gordon

Gordon,<br />

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As far as I know the DAC7 is all solid-state and does not upsample. <br />

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My interest in the DAC7 stems mainly from the fact that I own an ARC pre-amp (LS26) that I enjoy immensely.<br />

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My interest in the QB-9 is primarily driven by the engineering principles that you and Charlie have put forth in the online community.<br />

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I will definitely try before I buy, i'm just having fun gathering information at this point.<br />

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thanks for your feedback!

Guys,<br />

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After a long talk with all involved the review has been upgraded to correct for the mistakes regarding the miss use of the term Asynchronous USB with the DAC7.<br />

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http://www.soundstagenetwork.com/ultraaudio.com/equipment/arc_dac7.htm<br />

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Thanks<br />

Gordon

Thanks for the link to this review of the DAC7. Looking at the website of Audio research there are two more reviews apart from this one. <br />

http://www.audioresearch.com/reviews.html<br />

The reviews are quite good. But they seem to point out that the usb input is not as good as the other ones, not mentionning the fact that it is limited to 16/44. One review (Hifi news) states that the jitter is 350 ps compared to 95 ps and that the S/N ratio is 100 compared to 110. The other review(Hifi world) states the top end treble does not go as far as the BNC input, a point that can be compared to the ultra audio review.<br />

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I wonder if those differences can be the result of the program playing the music. With a PC I have tested a DAC7 with itunes, with foobar with direct sound and with foobar with asio driver. My experience on my system is that there is a real gap if you use asio driver. It is especially true with the trebles which do not go as high without the asio drivers.<br />

I have experienced the same sound issue with a musical fidelity integated amplifier A1 which incorporates a usb DAC. <br />

Can the windows kmixer increase the jitter and decrease the S/N ratio?<br />

Since I have no technical background on those issues, my question may be irrelevant...<br />

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If the other inputs of the DAC7 are better, how can I use them with a PC?<br />

Would you advise going for M-audio transit usb card which allows 24/96 and allows the use of the optical input? Any idea on the Bel Canto usb link with BNC output? Any other idea?<br />

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Thanks for your help<br />

<br />

Laurent<br />

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Ps : It would be great if Chris could test the DAC7 but as it is said, nobody is a prophet in his own land...<br />

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Chris <br />

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is there a review on the ARC Dac7 forthcoming ?

Hi salwani - There is nothing in the works at this time.