Trident 65 crosstalk in master mix

[AudioIngenia]

I have restored a Trident 65 mixer.
A new PSU Blue Dog and reinforced voltage traks.
Everything works correctly. But there is a small tone signal from the generator and a talback mic signal that is derived to the mix bus. The level at the master output of these noises is approximately -65 dBu. It seems that each channel provides a small amount of these signals to the mix bus.
Any suggestions?

 

[radardoug]

You normally turn off the tone generator so it doesn't leak onto the bus. -65 is probably about the level it would bleed.

 

[AudioIngenia]

yes. I can turn off the oscillator. but the talkback mic is not possible. Add garbage to the master bus, even with its minimum level.

 

[radardoug]

Is your talkback mike modified with lots of gain? If its leaking, could be a faulty relay. Or switch if there is no relay.

 

[Rocinante]

I interned (and later worked on) a Trident 65 and the chief took the talk back module out because of that same problem.  The chief engineer built one instead that fit into a 1/2 rack 1u. That same chief engineer was who taught me how to repair gear and pointed me to the Jakob's site so I could build my own SSL.

 

[AudioIngenia]

Anyway it is inaudibly.
It seems to be an inherent part of the design of this console.
Back to the past analog world.