OK, another one for all you who haven't managed to get a box at the opera
tonight:

My recent Chinky EL34 amp acquisition comes with fixed bias and trimpots and
no damn instructions. I don't know - is the *bias* fixed by the valve type,
the circuit (which I suspect it does) or by this figure which all four
valves are (rather conveniently) labelled with:

'1a: 31 mA' and 'S: [nothing]' - (wossat one?)

as per:

http://www.apah69.dsl.pipex.com/keit...pychinky08.jpg

.....and any idea what the voltage might be and would it be + or - ???


I'm not yet au fait with the thermionic ping-pong games that actually go on
*inside* valves - only the broadest principles. (The only other amps I've
got that require bias adjustment rather conveniently have the voltage
printed on the chassis!!)

TIA

(out now, back later)