Very well built enclosure with a nice, smooth finish, with a tactile and linear volume pot. I did also experience some hum through my speakers but that was fixed by removing the earth connection in the power cable. There is no need to open up the preamp to disconnect the earth. Now it is silent.
It requires a few days of break-in, thereafter the sound becomes much more refined and spacious. It is a really enjoyable listen, smooth and non-fatiguing with excellent detail retrieval and well controlled transients. Tonal timbre is also excellent.
Digging a little deeper, this board appears to be based on an Accuphase C3850 design, although I can't be 100% certain. Nothing to complain about here, it sounds fantastic.
It has a lot of gain - so much so that I reduced my pc output gain by -8db otherwise you don't get to use more than 1/4 of the volume pot sweep range.
My front end consists of toslink from pc feeding into a Audiophonics DigiRescue reclocker toslink to coax converter, a SMSL SU-1 dac fed via coax and rca out to this preamplifier going into active studio monitors with rca cables. This combination is the finest sounding front end I've ever owned. The law of diminishing returns applies here and I feel I would need to spend multiples more to improve my front end.
The preamp on its own is already a great improvement to sound quality, but if you can rig it up like I did you will be in for a surprise. This is my best hifi find for 2023 and I can highly recommend it. Thanks!