beerbunny;153750 Wrote: > Thanks for this suggestion. It's a great idea and helped me to (I think) > understand what is going on. I set the NAD aside and ran 1) SB2 optical > to Yamaha: good sound and bass; 2) SB2 RCA to Yamaha: poor sound, weak > bass; 3) didn't have digital coax cable so no SB2 digital coax to > Yamaha; 4) SB2 optical to Yamaha, Yamaha RCA to NAD: good sound and > bass; 5) SB2 RCA to Yamaha, Yamaha RCA to NAD: poor sound, weak bass. > After running these tests, my guess would be that the Yamaha's DAC is > superior to the SB2's DAC. Do you agree? I don't necessarily agree with your conclusion. My experience is that the SB2 DAC is actually pretty high quality.
Do we know whether the Yamaha digitises its analogue inputs? If it does, then there is bound to be a gain mismatch between the digital and analogue inputs, and this could easily account for perceived quality differences (louder is generally interpreted as better). Here's the reason for the gain mismatch. When you use a digital input, it can simply be passed straight to the DAC. When you use an analogue input, it has to be passed through an A/D converter. Now, since the Yamaha cannot possibly know what signal level you might feed it, it has to operate the A/D converter at a level so that the largest conceivable input won't cause digital clipping. Therefore more typical input levels will be operating the A/D converter below its peak level capability. Apart from getting a quieter digital signal (compared to feeding the SB digital output into the Yamaha), you'll also be losing a bit of resolution. But I'd be surprised if the Yamaha didn't have a decent 24 bit A/D converter, so the resolution issue shouldn't be a big deal - my money is on the analogue input simply providing less volume. (Of course if the Yamaha has a poor quality A/D converter, then that could be a much more straightforward reason for the reduced quality via its analogue inputs). Incidentally, to test the SB digital coax, just use any RCA lead you have lying around. As long as the length of cable is not too long, you'll be fine. -- cliveb Performers -> dozens of mixers and effects -> clipped/hypercompressed mastering -> you think a few extra ps of jitter matters? ------------------------------------------------------------------------ cliveb's Profile: http://forums.slimdevices.com/member.php?userid=348 View this thread: http://forums.slimdevices.com/showthread.php?t=29526 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
