[Boatanchors] 4-400 tube replacing a 3-400z for circuit test

[Greg Mijal]

Hi:

Has anyone used 4-400's in a made for 3-400Z's amplifier?
I have a Swan MK 1 amplifier built for two 3-400Z's and no tubes.  I do have a set of 4-400's.  The necessity of this is to evaluate the amplifier overall circuit, not necessarily "Convert" the amp.
Anyone do this one before?
Thanks
Greg
WA7LYO
in sunny Feenix