Please see this modification site for this amp !!!
Without these modifications this amp will not perform as hifi amp. And:
Forget the preamp section! Connect a RCA jack to the grid of the second EF86
and use the power amp section only....
Then you get a
well working amp with a
power output of 4.6 watts rms into 16Ohms @ 1kHz (about 3 watts on 8Ohms)
when you use good tubes and after carrying out the mods. The frequency
response is not so good as in the EF40 version.