Archimago wrote: > Good post Quad. > > Don't worry, I don't think in general the folks here are mean spirited > over a hobby :-) > > Nice summary list. Good to see you've gone over a number of > possibilities and listened for yourself. I'm 41 now and over the years > have tried a few of the tests and measurements as well. Something I've > run into frequently has been the importance of test methodology. For > example, there were times when a group of guys got together to listen to > 2 speaker cables and everyone seem to agree that Cable A is better than > Cable B, but the moment someone switches it and the test becomes 'single > blinded', that effect is gone. > > Likewise, testing DAC's, the moment we introduce controls like making > sure the volume is <0.25dB between the two units, there's no way any of > us can tell the difference in an A-B test between decent solid state > DAC's. > > Since you mentioned you haven't tried double blind testing, why not do > just a controlled straight forward 'instantaneous' A-B with the Touch > vs. NAD 514 into the M51? > - NAD 514 --> coaxial --> M51 > - Touch --> optical --> M51 > - Get a pink noise test tone and use a sound pressure meter (like the > Radio Shack one) to make sure the two sources are about the same dB > (should be if bit perfect unless M51 has independent volume controls for > each input) > - Go ahead and use the Touch digital volume control to change the volume > until the output SPL is <0.25dB different (this will bias against the > Touch of course, 100% volume is bit perfect for the Touch) > - Play the same album on both the NAD 514 and Touch at the same time. > - Flip back and forth between coaxial & Toslink (NAD 514 vs. Touch) - > does the music sound tonally different from the 2 inputs? Resolution and > dynamics differences? Would you or someone sitting with you be able to > differentiate the two if blinded to the source of the input? > > Realize doing this biases against the Touch both in terms of using the > digital volume control and TosLink generally has worse jitter. > > Potentially lots can be talked about but I think the procedure above > should be quite straight forward and would be worth doing to test one of > the assertions about bit perfection and audibility if you haven't > already tried. (If you need to adjust the Touch's volume it would of > course not be bit perfect and you would need to ask why the M51 plays > digital input at different volumes if this were to happen!)
Thanks for your reply Archimago. I will get a TosLink cable and follow your instructions. I really hope I can't reproduce my findings. ------------------------------------------------------------------------ Quad's Profile: http://forums.slimdevices.com/member.php?userid=20234 View this thread: http://forums.slimdevices.com/showthread.php?t=98374 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/audiophiles
