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asynchronous USB dac or jitter reducing device

Hello
I have a Red Wine Clari-T driving a huge single driver baffle. The range is roughly 80hz to 15k. I am interested in a macbook based digital system using Wifi or usb. The only piece of the puzzle I have is the MacBook. My budget is less than 1K including airport express or other similar, an asynchronous USB dac and or a DAC and pace-car type reclocker for jitter. If I have an asynchronous USB dac do I need a separate device for jitter? The Pace-car is clearly out of my budget, so what are my options?
Thank you in advance.
nparbat
kijanki's avatar
kijanki
4,428 posts
 
Paul is right - used USB version will not only guarantee later version without problems I mentioned before but also better op-amps in the output stage and therefore lower output impedance on balanced outputs. It just happen that best jumper setting for me is -10dB and I don't want to use it because of very high output impedance at this setting. Newer op-amps are stronger (LM4562) and divider is different. Also USB gives more flexibility.
drewh1
115 posts
 
FYI, The EMU has an async USB interface that reduces jitter and compares favorably with other expensive USB DACS I have listened to.
larry_s
128 posts
 
With asynch USB the only jitter you have will come from clocking the data from the USB data buffer in the DAC "box" to the DAC chip itself. There is no clock recovery or clocking of data from the source to the DAC "box" similar to what's done with S/PDIF. Excellent white paper about all this on the Ayre site.
paulsax
275 posts
 
Straighten me out as needed everyone. My understanding is that jitter reduction methods in DACs and whatnot reduce or eliminate the jitter added in that component. If you get jittered data coming in from outside you cant do anything about it. If this is indeed correct that implies that you cannot added a separate device to reduce jitter.
kijanki's avatar
kijanki
4,428 posts
 
No, they reduce all S/PDIF jitter (transport, cable etc). They cannot reduce jitter of their own D/A clock.

There is also jitter in A/D process - that one cannot be removed. Poorly digitized tapes at the beginning of CD have to be digitized again (with better clock).
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