"Keith G" wrote in message
...
Apologies for the delay for this 'joint reply' - interrupted by a little
post-prandial 'digestif' by way of a spot of Delius and VW (Larka Sending
and Symphony No. 6 - still playing! :-)

*Massive thanks* to *all* who responded and were, between you, just about
right on the money, from what I can see of it!! (Fekkin' valvies - too
damn sad/skint to be out on the ****/tiles/razzle on a Saturday Night!!
:-)

(I dunno!!)

OK. First up, the valves read as follows (Test voltage, amp on /
Resistance, amp off - the DVM wuz under me bed!!)

V1 = 0.317 V / 10.2 ohms (10R2 ??)

V2 = 0.303 V / 10.0

V3 = 0.322 V / 10.2

V4 = 0.318 V / 10.5

(I'll check tomorrow, but I thought the voltage readings were all "+"
???)

Next, the valve labels are all as follows:

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

Now, call me a bluff old cove, but this looks to me a bit like we want
is -37 VDC on the grid (am I right?) - ie. the 'test' voltage?? If so the
valves are all(consistently) 'underbiased?

What do each of these figures mean? (I understand about the valves being
'matched' but I thought was mA / V or summat??)

Many thanks, once again.





Hi Keith,

I'm just wondering if they supply the amplifier with brand new but tested
valves i.e. not burnt in for say 10 hours to allow anode current to
stabilise. If this is the case they may supply the amplifier underbiased
with instructions (if you had them!!) to run it for a while then increase
the bias point to the correct anode current when all the output tube anode
currents are stable (i.e. the bias reading at test points are finally static
and settled down) Just a thought - I'd still get back to the supplier.

Cheers

Mike