[bangraman]

I've just bought one of these from a fellow member.
http://www.worldaudiodesign.co.uk/wadproducts/hd83.html
I just saw 'kit' 'valve' 'adjustable impedance matching' and just kind of got it on a whim. Anyone but the seller have personal experience of these? Hints? Tips? Don'ts? I'll be using my long-neglected HD600 with these.

 

[aeberbach]

A really nice amp - I built one as the instructions said at first and it was fairly good. I built it again with point-to-point wiring (threw out the printed circuit board) and it was even better! Be most careful with the AC filament wiring, you need to twist those wires well (an electric drill is useful) and you need to keep them right away from everything else in the amp or you will pick up hum. You might also consider setting the transformer impedance by joining the wires together closer to the transformer, they don't need to be taken up to the circuit board and joined there. There is plenty of room for experimentation with different capacitors too, I used a couple of Multicaps in mine.

 

[bangraman]

Thanks. It's apparently been built by World Audio themselves, so hopefully everything's been done professionally, I'll take a peek inside once it arrives.