yes i see the op in the shematic, but is this preamplifier
any good. the author of design say that the sound is very
good. can this preamplifier can be conpared in sound quality with Pass bride of zen.
'Good' is a thing that's hard to define, since it's a matter of taste, just like red wine.
In this case we only have the designers word that it's good, and that's in comparison to a preamp which probably none of us has ever heard.
To know weather or not it's comparable to the Pass Bride of Zen, I guess someone has to build both, in order to make an A/B-listening test.
To make a long story short. If you feel confident in the circuit, and it's maker, build it. Is there anyone in this forum who has tested or heard their amp, before they have build it? I doubt it. I, for one, haven't. I just made the amp(Pass ClassA), and found out, that the rumour was right. Pass was a designer to be trusted.