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    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

6bl8 el84 nfb question

hello all friend of mine gave me this sylvania amplifier awhile back it came out of an old stereo console it uses 1 6bl8 and 2 el84's per channel.
I have replaced all the coupling caps with cheap polypropylene types of the same values and replaced both of the 100ohm cathode resistors on the el84's.
I got it fired up tonight on the variac and used a walkman to play some music through it and it seems to have way to much gain and when theres no signal being applied it sounds like its wide open and makes a audible hiss.
From what I have gathered on the web from different forums and people who collect and restore consoles is that there was a preamp/tuner in the console and it had the balance and I guess the other half of the negative feedback circuit . Is there a way I can fix this weird looking thing up to be a stand alone amp with no volume pot ? Heres a pic of 1 channel of the amp.


Below the 6bl8 is the opt which is on the other side of the chassis and to the right is the input jack. Any help would be killer :) Heres a pic of the weird looking thing.


looks like it started out single ended ?