Fender Tonemaster channel switching Pop!

[bibi]

Hello,


I am currently working on a Fender Tonemaster amp and it has a problem with the switching relays between the two channels-- namely it pops. 
The circuit as can be seen from the schematic included is minimal at best-- +24V going to the relay and a 4148 diode across.  I have found reports
of this being a problem from the beginning and no wonder!


Is there any known Fender service repair notice for this amp that I haven't found?  I could modify it pretty easily to be an adequate circuit if that is
the best solution.


Thanks for your help!

[VMS]

This schematic shows R66 2M2 resistor after the relay and before the PI:


https://el34world.com/charts/Schematics/files/Fender/Fender_tonemaster.pdf

[tubeswell]

Bruce Zinky was eventually fired, so I heard.

[bibi]

Well the schematic I posted is a Revision E so that should have addressed some of these issues as it is later than the one on this website. 
Unfortunately, it looks likely I will have to do some modifications to get it halfway decent.