Tweed Super (5F4) rectfier alternatives...

[Cobra]

Can you safely use a GZ34 or 5V4 tube in place of the stock 5U4G in a Tweed Super(5F4) circuit? I have no 5U4G's, but I have several GZ34's and 5V4's in my tube stash. Any issues or concerns using these tubes, please advise.
Thanks much!

[TD_Madden]

I've been told GZ34s are fine...just keep the tubes biased at no more than 17 watts each.

[Bruce / Mission Amps]

I've been told GZ34s are fine...just keep the tubes biased at no more than 17 watts each.

It's probably safe to go as high as 20-22 watts if the choke and the power tranny's high voltage secondary are
up to it...
ie. ... rated at around 200ma.

[TD_Madden]

Bruce, since I have your 5F4 kit, is it safe to assume I can go up more than 17 watts?

[Bruce / Mission Amps]

Bruce, since I have your 5F4 kit, is it safe to assume I can go up more than 17 watts?

Yes, I use that same tranny combo you have in a cathode biased 6L6 harp amp and idle those power tubes at 20-24 watts each.
It's hot but the Heyboer PTs seem to handle it in stride.