[Amps] Multi-tube vs Single or Dual-tube amps?

[Peter Voelpel]

No to all.

I used cathode resistors 10 Ohm with all my multi parallel sweep tubes in
the past like 14x PL36, 6x PL519, 6x 6DK6 etc. and just a single amp meter
and bias pot.
Also had 2x12 PL519 push pull working.

Never selected tubes either, they all where tv set pulls, except for the
6KD6 amp which I used mobile.

73
Peter

-----Original Message-----
From: Amps [mailto:amps-bounces at contesting.com] On Behalf Of Jim Thomson

The problem with multiple tube amps is trying to
balance the plate current between them all.  They really need to be matched.
They also need to have individual, adjustable bias controls, so that the
individual idle currents  can  be matched.  They also require individual
plate current metering.