It is the version with ECC81 driver tubes.
Unfortunately it didn't come with any documentation.
Now I try to bias the amp for el34 and 6P3S-E tubes.
I installed all tubes, connected amp to preamp and connected speakers to amp,
turned on the whole system and made sure no signals go the the amp.
Then I measure the bias of the front left tube by placing the black probe
on the chassis and the red probe in the 'Biasset 1.56v' hole
and adjust the adjuster until the reading is about .4 V.
For the back left tube I placed the red probe in the hole on the opposite side of the socket.
Then I did the same thing on the right side.
I did go back and check all reading. they are all about 04 V now.
The system was on from the beginning until I was 'done'.
I am not sure if it was the right way to bias this amp.
Oh, And if someone has a copy of the user manual please email me.
I would appreciate your helps. Thank you
Last edited by hrudu90 on Sun Jul 22, 2012 2:31 am; edited 2 times in total