Benchmark DAC-1 Get The Most Out Of Your DAC-1
Like all other reviewers I like the DAC-1's transparent and neutral sound, but many people may not have got the maximum potential from their DAC-1.
In the past 6 years I've owned all versions from the original DAC-1 to the USB/PRE/HDR, and have tried different configurations in different systems from tube to solid state to active monitors to headphones.
In all cases I found it sounds MUCH better if you:
(1) Use XLR output instead of RCA
(2) Set the XLR output jumpers at "0 dB"
(3) Set the headphone jumpers to "+10 dB gain"
(4) Set the output to "Calibrated" instead of "Variable"
A few notes and explanations:
(1) The DAC-1 was originally designed for professional audio where XLRs are more popular than RCA. I've owned a Cary 306 whose XLR performance is very close to RCA, and I know there are superb sounding DACs out there which only have RCA, so I am not against RCA, but the XLR on the DAC-1 is WAY BETTER than its RCA. To take this advantage, you need fully balanced, differential pre/pwr amps to work with the DAC-1.
(2) When the XLR output jumpers are set at "0 dB", the output voltage can reach a max of 10 volt, which satuates a lot of preamps especially tube preamps. If you hear noise that means your preamp's input stage can not handle it. If you decrease the output voltage, the output impedence goes up and the sound becomes less transparent/direct. Again, 10 volt is for pro audio, not Hi-Fi, Hi-Fi sources normally output 2~4 volt on XLR.
(3) The headphone gain jumpers works pretty much like the XLR gain jumpers. When you use "+10 dB", the sound is more dynamic and transparent than "0 dB". Of course you have to turn the volume knob down to get the same listening level. DAC-1's headphone amp fits low-impedance headphones (~30 Ohm Denon or Audio technica) better than high- (300~600 Ohm Senn or Beyer).
(4) Assume you have an High-end balanced preamp, the DAC-1 sounds better as a DAC with calibrated output. But if your preamp is not top notch, running DAC-1 directly into a power amp may give you pros and cons. There are many threads about preamp v.s. preamp-less sound.
(5) Over the years DAC-1 has received some revisions and the newer units sounds smoother and less agressive than the old. But if you don't need the analog input, DAC-1 USB sounds slightly better than DAC-1 Pre/HDR due to simpler circuits. The HDR sounds different especially when you use variable output -- it's got a different potentiometer. Whether you like the difference is up to personal taste and system match, but after trying all models, I've sold the HDR and will stick with DAC-1 USB as a DAC only (with external preamp).
(6) DAC-1's USB v.s. other USB/SPDIF converters: I found DAC-1's own USB input to be very good, adding another USB/SPDIF converter could lead to plus or minus. I have tried Logitech Transport, Halide Bridge, Stello U2, and a friend of mine tried M2Tech Hi-face Evo. We found while one maybe superior than the other, each device adds its own signature to the sound. Stello U2 by far is the most natural sounding device and Halide Bridge condenses the sound which you may or may not prefer.
Overall, DAC-1 is a superb DAC at an affordable price. When setup right, the DAC-1 can compete with high-end digital front end. You may not like DAC-1 if your personal taste leans towards a forgiving, laid-back presentation with somewhat recessed treble and sweetened midrange.
The DAC-1's pro audio heritage may give you some trouble choosing the right preamp, but as a plus, try DAC-1 directly into a quality studio monitor, which is what DAC-1 is designed for. Even a moderate Dynaudio BM5A Mk-II may surprise you. Cheap studio monitors will not sound as refined as your Hi-Fi, but there are something foundamentally "honest" and "right" in the music.
Enjoy your DAC-1!