[Phil Allison[_3_]]

I can also add that now trying 5R4GYA's for rectifiers in the Quad II's
brings the B+ voltage down to 337v (yay! within specs!) and everything runs
comfortably halfwarm instead of hot. The 6L6GC heat up more quickly than
KT66, so the voltage peak (440v) at cold startup lasts for only 10 seconds
or so. If only there was a place to add a standby switch and this would now
be solved. The trouble of restoring to original appearance...


** Huh ?

The input and AC supply connections used on a Quad II are horrible and
impractical. So I long ago fitted a standard IEC inlet to mine and also an
aluminium cover plate with a 6.3mm jack behind the input socket hole. Looks
very neat and is very practical.

The output valves are Sylvania 6L6GCs - made in the 1980s and used mainly
in guitar amps. They out perform and outlast all other 6L6s or KT66s. My
Quad II tests 0.03% THD at 10 watts output.

The PSU was rebuilt decades ago, as the original 120V PT was burned out by
connection to 240V mains - so I have a bridge rectifier, 100uF 450V
electro, original choke and 56uF 450V electro now. The DC supply is 362V at
the first electro. The electros are compact, single ended types held to the
chassis with Silastic.

All the small components, valve sockets, tag board and wiring are new since
I stripped and replaced the lot about 6 months ago. Cathode bias is by two,
390ohm, 5 watt cement resistors in parallel (= 195ohms) .

The new 9 pin sockets have snap on COVERS - so the poor EF86s are no
longer exposed to accidental damage.

Oh, and I have a dummy valve (5AS4) in the rectifier socket for appearances
....



..... Phil