on December 6, 2012
Just starting to listen via FLAC (lossless) ripped CDs via USB using the Foobar2000 audio player under Windows XP SP3, but the accuracy and detail are phenomenal. Foobar2000 output is set to 24 bit. All software configuration settings recommended by Benchmark are used. Headphones are Sennheiser HD600 with Cardas cable. Need to try with high resolution 96 kHz x 24-bit and DSD audio next. DSD will need to be via the DAC1 PRE analog inputs. Will update more on sound of high resolution sources later.
Even the fact that it can be this good over USB is outstanding; Benchmark's claim about fully taming jitter over all interfaces including USB seem to be correct, judging by the resulting sonics. USB should be the worst for jitter, conversion errors, etc., and it sounds fantastic. Totally clean and extremely accurate. Need to try Toslink and S/PDIF. If their jitter claims are correct, then all interface types should all sound very similar.
The headphone amplifier circuit is completely effortless and as clean as I can hear; sublime. Have not tried the analog outputs.
Construction, operation, user interface, pretty much everything about it is rock solid as befits beautifully and highly competently engineered professional audio equipment. Even the instruction manual is very well done.
This is a version 2 with a manufacture date of October 2012. Unfortunately DAC1 PRE is being discontinued in favor of the DAC1 HDR version which adds a motorized volume control and optional remote control which costs $100 or $200 more without or with the remote. So this may be among the last DAC1 PREs produced.
At some point in the last 5 years Benchmark changed from using a mix of 5532 op amps plus LM4562s to all LME49860 throughout. Stereophile's John Atkinson reviewed a version with both types of op amps in 2008, so the change must have been after then. The LM4562 and LME49860 are regarded as among the best op amps in the world, so this was a great change. The 5532 is a good sounding op amp, but very old and hardly state-of-the-art. One Texas Instruments-sourced 5532 still seems to be used in at least the headphone section in my sample. The headphone amplifier is based on another Texas Insruments chip, the LME49600. DAC chip and Asynchronous Sample Rate Converter are Analog Devices AD1853 and AD1896 respectively. USB interface chip is TI TAS1020B. Digital Audio Transceiver is an AKM AK4114. All the digital and analog audio chips are very high performance.
This is a phenomenal DAC / preamp / headphone amplifier. Really, really good.
Update: lossless FLAC over USB is very good, but unfortunately CD over Toslink from my Pioneer Elite universal disc player is definitely better sounding. This is unfortunate because it means computer-based audio may be inherently inferior, probably due to jitter effects. The difference is small for non-critical listening, but noticeable. Voices are clearer and more realistic, instruments are more realistic, reverberation tails are cleaner, hall sound is more distinct from the external disc player. In general the same bits from the computer sound more veiled and hazy compared to the external CD/SACD/DVD disc player. Very often, that's a sign of greater jitter, especially since the bits should be identical; in principle the only major difference can be jitter.
High resolution audio like 96 kHz x 24-bit is far more realistic sounding than CD, but we knew that 15 years ago.
A couple upsides: First, the Benchmark DAC did do a very good job cleaning up the USB, so computer-based audio may be viable for casual listening, if definitely not the ultimate in fidelity. The difference between computer and disc player sources is small enough that casual listeners probably won't be able to hear them. (But then why would non-golden-ears be buying an audiophile product?) Second, the Benchmark easily has enough fidelity to make these differences audible, which actually speaks well of it and is an indication of very high quality. In other words the weakness is in the computer medium, not in the DAC itself, which is superb.
Have not tried S/PDIF from the disc player yet; may be better than Toslink due to the usually lower jitter.
on February 8, 2014
I bought this machine years back. My speakers are worn and my amp is a good freebee. I was considering buying piles of costly equipment, but ended up stopping here. I never knew how much distortion a typical analog to digital converter introduced. AirPlay receivers sound terrible. Headphone->RCA mismatch. The receiver's optical input jack was the worst of them all. The DAC1 proves that optical is the cleanest way to transmit a digital signal to a typical or better home amplifier.