manicm:idc:
I disagree manicm that Naim have 'all but given up on the PC as a source'. (EDIT - not true anymore, I stand corrected) From their site it lists the various products that can be connected to the DAC, from ipod to TV and it includes;
"Connect a PC external sound card digital output to play stored or network music"
So all that means is that you need SPDIF to connect to a MAC or PC and you cannot use USB. If you want to connect your PC to the Naim DAC and you do not have SPDIF, as the website states you need a soundcard, so an off board one will do. (EDIT - which after checking is not easy and in reality, unless you have optical/digital coax out on your PC, forget the Naim DAC) Benchmark have taken a different route by adding USB to its DAC1, as has the DACMagic, Beresford etc. So whilst it is not impossible, Naim have gone in an odd direction contrary to other DAC makers.
The route taken to reduce jitter is by buffering and then clocking the data, which is similar to synchronous USB;
"The Naim DAC has more in common with Naim CD players than with conventional external digital to analogue converters. It overcomes the jitter issues of S/PDIF by reading the data into a "rotating" data RAM buffer independently of its timing signal and reading it out again clocked by one of ten extremely low noise, fixed frequency crystal sine-wave oscillators. In terms of system topology, the DAC's rotating memory is analogous to a rotating CD feeding raw data to be re-clocked. The rate at which the memory fills and empties is controlled by the DAC automatically selecting the oscillator that matches the average incoming clock frequency. The data entering the downstream digital filtering and DAC chips is then completely isolated from the incoming S/PDIF jitter."
(EDIT - So why not have a USB connection to PCs as well?) All Naim have done is a different approach to the same problem.
Hi idc, sorry I stand corrected - I meant PC thru USB - I think Naim feels it's not worth the cost and bother to get it to an acceptable level.
As you said PC/Mac should not be a problem, can get an external sound card with spdif out for the former.
Yes and I finally found what I couldn't last night means of doing that, the M-Audio Transit, £57 off Amazon. An easy way to connect PC USB to DAC digitally. So my first two EDITs above are wrong.
What Naim, Benchmark, Wavelength and Ayre have done is pretty much eliminate jitter. I now understand that my Fubar USB DAC does suffer from jitter. I get cracks and pops and I am sure clarity and detail can be improved.