I like to reply to these threads. I am Latin teacher and build these things. No technical background whatsoever. The manuals are the absolute best in hifi. Doc loves photography and it shows. You could almost build the kits from the pictures alone, the manuals are that good. The problem is never the person's ability to build the amp from the manual, it is someone who rushes and doesn't check their work before firing it up. If you pay attention and double check you can very easily do it. Trust me, you can handle it.
I'll second that bit about checking your work. When I built one of Pete Millett's headphone amps from scratch, after I'd made the last solder joint I didn't fire it up -- I deliberately stopped. The next day I started with the AC plug and checked _everything_ against the schematic. Every wire, every pin, every everything. Even tho I'd been very careful in assembly, I found I'd polarized both output caps backwards, and both MOSFETs were upside-down-backwards. The problem of course is that whn you finish a project you get _physically excited and impatient_, and that's really what makes the sparks fly. But since you're an engineer, I'm sure you know not to fall into that trap.
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Physics is love; engineering is marriage. --Norman Mailer