Denon DAC DA-300USB
Picked this up cheaply on Amazon recently, wasn't expecting too much from it but was happily surprised by the quality.
Its a substantial beast as these things go, weighing 1.5Kg, it uses the same Burr-Brown PCM1795 chip (combined with Denon's AL32 DSP) used in Denon's DCD-2020AE SACD Player which costs around £1500.
I've used it mostly in a Computer setup with Windows 7, running Foobar2000 and Denon's ASIO USB driver. Connected to a set of M-Audio active monitor speakers.
Sound quality is a big step up from a PC sound card, even running from cold. It has a rich timbre with voices and acoustic instruments and provides good stereo separation. I could not really judge its high and low frequency extremes as the speakers were a limiting factor. So I connected it to my main system using a Marantz SA-11S2 as a transport. I tried both coax and optical connections, not much difference between them.
The performance of the DAC continued to impress running though full range speakers. It matched the DAC in the Marantz for detail, but had a slightly warmer sound. One problem did show up at this point. The Denon DAC uses a cheap switch mode power supply, this injects a slight hum into the audio output, even when the DAC unit is powered off. Once you unplug the power supply the hum vanishes. This hum was present on the computer setup but was not loud enough to hear over the PC background noise. If I was going to use this DAC in my main system, I would probably buy a linear mode power supply with a 5v output to replace the stock PSU. However, at this price (around £180) its a minor issue.
