Transport for DAC

Shadorne -

"To me the greater the precision the more problems/anomalies you discover in your recording collection."

This is very true. I discovered big difference in recording quality with the Benchmark. I like its clarity but it took a while to get used to it. At first I had impression that something (some instruments?) must be missing. I even heard opinion that "sound blob" performance is more musical than "analytic" Benchmark's performance where you can distinguish individual instruments. Some like also a little THD to make sound "lively".

I hear people saying that all is subjective and if you like it it's better for you. It took me a while to really like Benchmark and I'm always ready (with my limited experience) to learn to listen.

I can hear a little livelier sound at 0dB than -20dB but -10dB is much worse and my 0.5m cable has total of only 6pF/ft x 1.5ft=9pF.

Are you using the calibrated output - bypassing the DAC1 volume control?

What you report strongly suggests that the device (power amp or preamp) that you are connecting the XLR outputs of the DAC1 to - this device has a rather low input impedance (much less than 20K). I'd check this angle out - many power amps have simple input attenuators (rather than variable gain) which may lower the power amp input impedance (depending on the power amp volume/trim settings and the design).

Also if you are using adaptors to take XLR from the DAC1 to RCA then be aware that pin 3 must be left to float or yo'll get distortion.

Shadorne - I'm using XLR cable without adapters. The only gain adjustment with XLR is either 4 jumper settings or volume knob on the front (if you chose this mode).
I'm using volume control (no preamp).

My power amp (Rowland 102) has only XLR inputs rated as 40k impedance. 9pF with 1600 ohms of output impedance makes fc=11MHz. It has to be something else.

I would thing that I might compare different levels or "hearing things" but review I read claims the same and Benchmark lowered this output impedance with stronger output drivers and lower dividers in DAC1 USB. I will try to find link to this review.

My power amp (Rowland 102) has only XLR inputs
rated as 40k impedance. 9pF with 1600 ohms of output impedance makes
fc=11MHz. It has to be something else.

It has to be something else.

I agree 100% - which is why I asked. It does not make sense unless
something else is going on.

The only thing I can think of is ground loop or RF/EM pick up. If you raise the
output impedance of the source to 1600 Ohms then you are surely much
more susceptible to RF or ground loop effects if there is any imbalance to
ground anywhere in the circuit. As you lower the output impedance of the
source you will kill any ground loop or RF/EM signal versus the true signal.

The fact this translates to more dynamics sounds intuitively correct...basically
cleaner sound is likely to sound more dynamic with more
"blackness"...

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