Fender Deluxe vibrato problems

I like the way you think  8)  I'm just looking up my notes  ..  from my ab763 build  tremolo  stuff  ...

In the meantime, here's a pic of what is  ..

I looked at my notes on the ab763 vibro from my diy super reverb clone  ...

There was a fender service note (which others have mentioned over the years)  ..  that adds a 0.01uF 450V mylar cap from the plate of the  AX7 stage 2  to ground  (osc gain stage).  I tried 0.01uF to 0.022uF

I did that mod, and I found it reduced the 'osc punch thru' but did not eliminate it.

I also noted the noise was definately coupling from the B+ and super hi Z 10M resistor, bug 'hv side'  area  and that experimental 'wire lay' changes made a reasonable improvement  ..

moving the wires closer to the chassis surface and 'holding them' in place  .. 

Maybe the fender 'old school wire-wrap-to-ground'  around the most sensitive wires might help.

....

Here's a pic of the AB763 trem  area  wiring  (not mine - tidier than mine!)  ..  maybe you can get some inspiration.

After that, I noted the 'neon' in the regular 'bug' wasn't helping ....  so I made some led-based opto bugs of different types    ..  I ended up with a white led and original cs photoresistor cell in a black heatshrinked tube.

.. and tried different 'plate loading' schemes of the AX7 stage 2  ...  'lifting the 10M' helped  to suit my 'led bug'.

I also slowed down the tremolo a bit by changing the osc caps to 0.02, 0.01, 0.02

and did some tube rolling for the AX7 till I found one that worked better  ...  but still when things get 'warm' in the chassis, the helicopters return occasionally  ..  but it's at a minimum.

That's been about 7 or 8 years like that now. 

Next time I open it up. I'll swap to ceramic caps while I'm there, I think.

.....

Good luck !

@ Alexc: Thank you sir...

The problem is solved by utilizing some shielded cable and wire layout... In this case I used the wires in the kit and it was the solid cables used in older Fenders... easy to solder but a bit stiff. They are however easy to dress if needed and in my case I tucked them pretty close to the tube sockets of V4 and V5... sort of separated them in to two groups.

And to experiment I added the suggested 22nF cap across the 10MEG resistor and the problem was solved. No, more ticking or flapping sound even on the highest settings.


Best regards

/John

Now I just have to try that - thanks!