Kijanki & Shadorne -- Thanks very much for the good comments and info. I looked at the manuals and Benchmark's comparison chart for all three versions of the DAC1, and yes the USB and Preamp versions are the only ones with the "State-of-the-art LM4562 high-current op-amps." The USB version has that op-amp in the output stage only, while the preamp version uses it throughout the analog paths.
A result of that is the 1600 ohm output impedance of the DAC1 with the 10db pad enabled is reduced to 425 ohms in the other versions, although that is still much higher than for the other settings of the attenuation pads.
But I too am mystified as to why the 10db/1600 ohm position should have produced such poor results in Kijanki's setup.
Thanks again for the good information. In my own case, when I make my purchase (probably in a couple of months), I think the choice will come down to the DAC1-USB, or one of two all-in-one cdp's (now there's a way to eliminate transport-to-dac jitter :)), the Doge 6 (tubes), http://www.pacificvalve.us/DOGE6.html or the Sony SCD-XA5400ES, both of which are in the same general price class and have received a lot of excellent comments. It's not worth it to me to go above that price level because around 80% of my collection and my listening is vinyl.
Regards,
-- Al
A result of that is the 1600 ohm output impedance of the DAC1 with the 10db pad enabled is reduced to 425 ohms in the other versions, although that is still much higher than for the other settings of the attenuation pads.
But I too am mystified as to why the 10db/1600 ohm position should have produced such poor results in Kijanki's setup.
Thanks again for the good information. In my own case, when I make my purchase (probably in a couple of months), I think the choice will come down to the DAC1-USB, or one of two all-in-one cdp's (now there's a way to eliminate transport-to-dac jitter :)), the Doge 6 (tubes), http://www.pacificvalve.us/DOGE6.html or the Sony SCD-XA5400ES, both of which are in the same general price class and have received a lot of excellent comments. It's not worth it to me to go above that price level because around 80% of my collection and my listening is vinyl.
Regards,
-- Al