help needed - AMI Continental 1 - sound deteriorates over paying time

Hello Guys,
happy to be here again !
would appreciate your advice as to the problem i encounter
when I hear songs one after another the sound get bad as time goes by

I don't know the right English word for this but it is loosing its quality
any tips here ?

it looks like its gaining back its quality if switch records (choosing a new song i mean)

Does something happen to the AMP, i.e. it gets into 'sleep mode' when records is back to the magazine or that the AMP is working all the time ?

so, need you help here, thankful as always

Eitan

Eitan, this can be mechanical due to a binding tonearm. Or, if the original pickup is used (GE) it can be that the cantilever us being pulled toward one pole piece due to too much lateral friction in the pivot bearing. the trip switch may be loading the arm and causing the problem.

First test is to simply pick up the tonearm when the sound deteriorates and place it back at the beginning of the record. What happens to the sound?

If these records were in this, or another juke beforehand it is possible they were damaged by the crude arms. Damage tends to get worse toward the center of a record.

If the sound stays bad at the beginning of a record when the arm is placed there after playing several minutes it will indicate a leaking capacitor or gassy tube. The B+ is switched between records on old AMI's and this sort of thing can happen. In more conventional designs with constant B+ once the leakage causes distortion during warmup the distortion stays and gets worse.

My vote here is for a mechanical bind.

Rob-NYC

Thanks rob
I will do the tests and try to see what is the cause
Eitan