old valve stereo-gram question

[9 volts]

I know this is off topic but I figured someone may know the answer to this. I notice when I use old 60's stereograms the balance causes the volume and bottom end to disappear a little (phasing?). Move the balance out of the centre and the bottom end increases. Wondered about this for a while. Restored one for myself and since it had to output transformers figured it couldn't be caused by phasing. Anyone have any insight into this? Thanks

[9 volts]

Restored one for myself and since it had to output transformers

whoops thats 'two output transformers'

[Nasse]

I am not sure what you mean with stereogram but I believe you should check pickup cartridge first, and the needle

[9 volts]

Thanks, stereogram means radio/record player in stereo (two channels). No problems with it as I've compared a few and the early ones seem to all behave the same. It's like a dip in the bottom end when the panning (balance) is dead centre. Just thought someone may know why this occurs..

[Nasse]

Other channel out of phase perhaps

[9 volts]

Just read up on OOP and this may be the problem, I never new this occured wiith stereo channels. oops (pun). Thanks