70s Electro Harmonix Stereo Memory Man troubleshooting

[Toxophilite]

I have an older Stereo Memory Man.
One of the original ones
It has a nice sound
It had been modified with a gain control and a feedthru(essentially a dry sound volume)
I removed the gain as it was in the 2nd stereo out jack and hooked it up again as I believe it should be
However whilst I still have chorus and echo, the 2nd stereo out level is very very very quiet when I play it through 2 different amps
Strangely when I record it into my computer the signals are the same level and not out of phase.
Annnd even weirder when I run it through my little mackie board into my crown amp into my tannoy reveals it's the same volume and sounds good, does the stero phasing thing

I've tried different amps, switching them etc

Any ideas?
Schematics for these old models are hard to track down
I have a kind if close one but it's...well kind of close no exact

I've been using it in mono but would like to use the stereo

[Ed_Chambley]

Is the impedance the same on both outputs? 

[jojokeo]

At the very least high res pictures would be helpful. Can't see anything you might've overlooked or not?

[Ed_Chambley]

At the very least high res pictures would be helpful. Can't see anything you might've overlooked or not?

This is my 2nd favorite avatar.  Eddie sure is young.

[jojokeo]

Yeah I was too back then (16)