http://kenrockwell.com/audio/benchmark/dac1-hdr.htm#meas
Note the DAC1 is "pro" DAC so the XLRs output about 12V RMS without output attenuators. With 20db attenuators in place it's about 1.2V RMS. So in a domestic setting, you need attenuation. The issue is, I don't like the sound of the output attenuators despite Benchmark's claims they are transparent. So I am using between 30-45db of digital attenuation. So what is 125db down in the jitter sidebands is 80-95db down for me. The natural response is "don't use digital attenuation" but the alternatives are less transparent to my ears! Is digital attenuation worse for noise and distortion than the alternative? See measurement captioned "THD versus frequency at 0 dBFS, -60 dB gain, 2 mV RMS output, 22kHz bandwidth." here: http://kenrockwell.com/audio/cambridge/dacmagic-plus.htm#meas and a direct comparison to the DAC1 HDR's physical pot which at -60db gain using its ALPS pot has similar distortion! Despite the HDR starting off with lower distortion unattenuated. I realise that Ken was testing this with HDR set to 20db output attenuators, my point is from a better starting point the physical attenuation of the ALPS pot is worse for THD than digital attenuation. Sure, fixed attenuators will perform better in theory but Ken's test shows that physical attenuation is no free lunch. The mechanisms I'm not sure about - thermal noise and changed impedance are the only two I know about for sure, but at the end of the day an additional resistor network put in the signal path is not desirable per se. The best response of all is "get a new DAC" ... and I will! But despite the discussion above it's sounding the best it's ever sounded set up this way! Check it, add to it! http://www.dr.loudness-war.info/ http://www.amazon.co.uk/gp/richpub/listmania/byauthor/A3H57URKQB8AQO/ref=cm_pdp_content_listmania/203-7606506-5721503. SB Touch ------------------------------------------------------------------------ darrenyeats's Profile: http://forums.slimdevices.com/member.php?userid=10799 View this thread: http://forums.slimdevices.com/showthread.php?t=100850 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/audiophiles
