kasperbergholt wrote on Sat, 04 December 2021 11:51

Hi!

I've upgraded from a preamplifier with a fixed mini tube to one with a standard socket accepting an ECC 82 (Audio Note M1).

I'm looking for recommendations on different tube types / brands / signatures to test.

It comes with an EI Yugoslavia produced in the 90's (on Telefunken equipment some sources say).

I've ordered an NOS Siemens E80 CC (which is compatible) and a NOS Telefunken.

Anyone with experiences with Mazda Belvu or Toshiba (which seems to be bang for the bucks and the only Japanese product receiving good reviews).


Thanks,

Kasper

Hi Kasper,

Just a note that the 80 and 82 are not truly compatible. There are major differences between them that affect distortion, clipping, dissipation etc.

1. filament current 600ma vs 300ma at 6.3 volts, check fil tranny for handling capability
2. transconductance ~2700 vs ~7000
3. mu ~27 vs ~17
4. plate resistance
5. plate dissipation 2 vs 2.75

As such, the plate voltages and currents will be quite different, requiring different plate, cathode resistors. Without changing these parts values, the clipping point and distortion characteristics will be different. Might also check the plate dissipation to be sure it is safely within limits.

You might make a go of it, but I could not guarantee the quality will be optimum.

Cheers and good luck with your endeavors.

steve