Regarding the sound quality the following statements can be given:
Subjective listening tests in comparison with a Linn Wakonda (commercial preamplifier, price DM 2000.-) at my local dealer showed the limits of the Linn, especially regarding dynamic, transparence, sound stage and at the frequency extremes. Both the dealer and I placed my high level preamplifier at a quality level somewhere between a Naim 72 and a Naim 82 (each with Hicap)--that is in a price range of DM 4000.- to 8000.- and all this at a financial expense of about DM 750.-.
I have to admit that I heavily underestimated the amount of time needed to design and build the preamplifier. First, because many minor cuircuit modifications were needed followed by extensive listening tests in comparison with my old preamplifier to get exactly the sound I wanted to have, and second, because the preparation and assembly of the housing and the pcb's (see 5.2 on page ) took very much time to finish--I'm not very good in mechanical work but I wanted to build something I could lay my eyes on every day.