Not good quality. it worked a few days, and one day it blowed at startup without any reason :(
Packed well. Sent quickly. Not tested yet.
Works great. Absolutely silent. It doesn't generate any 'wroom' in speakers, it doesn't interfere preamp. Additional +/- 15V is very useful for preamp. Power is exactly 500W. Very good quality and great value for money although 55V version received (while 50V version ordered). Neverthless - I recommend the Seller and the PSU.