If you do this test it will probably produce 19-25 dB Nulls - not great. However, this is not the whole story. Open the difference file in Audacity (or similar) and look at the frequency spectrum plots. You will find that actually the difference is more like -50dB, but with large differences at the low end of the spectrum (<100 Hz) which is skewing the result. Also you will see that ADM cannot compensate for the SB clock drift and you can still hear (bits of) the music.
What does this mean in practice? To improve playback quality and getter it closer to the original CD, we must: 1) use an external DAC with a better clock and more accurate (frequency/phase response/noise) analogue stage - ideally use a linked clock so that the DAC can drive the SB - this requires mods to DAC and SB. or 2) put a much better (more stable/accurate/low noise PSU) clock in the SB and mod the analogue stage to improve its transient and self-noise performance - presumably the SB+ already does this? or 3) upgrade to a Touch or TP which have better clocks/outputs stages and which measure better in this test (well, the Touch certainly does, others are looking at the TP as I don't have one). IMO Most of the "problem" lies with the analogue stage of the SB3. Those electrolytic caps can't be helping here and the driver IC can surely be improved?. Not sure what an SB+ looks like in this respect. -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... SB Touch Beta (wired) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker & Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio ------------------------------------------------------------------------ Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=71321 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
