[jrebman]

The TDSL data sheet for the EZ81 seems somewhat incomplete -- at least what of it I can access, so I'm trying to get some information about swapping an EZ81 in a design that calls for an EZ80.

This will be for a Mullard 3-3 amp which I plan to build this coming year, and aside from the fact that the 81 takes an amp of filament current and the 80, 600 mA, are there any other differences that would make using the EZ81 in the Mullard circuit a no-no?

I've never used either of these before.

Thanks,

Jim

[TheChairGuy]

Jim (aka, ab0ez here at AC) updated my old Bell integrated amps.  In doing so he re-tubed my wee ones...and used EZ81's for EZ80's.

Not sure in every case are they a straight swap...but they were for mine little 6V6 integrated monoblocks.

Food for thought, gentleman Jim Rebman....John

[f2a]

Hi
 Have enjoy  with You r project  in new  year . I think  this schematic has 3 pots ,yes? Ez80 and ez81 seam in capacitor filter but deferent in filament current as you explain. you can use separate transformer for filament .sound with two valve  is nice . 

[JoshK]

According to the data I just looked up on Frank's tube page, EZ81 is the beefier of the two, with higher PIV ratings, higher current output capability.  The price is the higher heater current.  If your amp have the available filament current there isn't an issue.

[jrebman]

Thanks, gentelmen.  I thought I had read somewhere that this was ok, but thanks for confirming it.  Now just waiting to hear from the transformer maker.

-- Jim