nmv twin reverb vibrato

[tonalvision]

I have been going through a 1971 twin reverb to check the components and noted some differences from the aa270 wiring diagram and my amp. So I modified my amp to agree with the diagram and have now lost the vibrato function. Hooking up the neon bulb it will "flash" when the footswitch is engaged and then just glow softly, no oscillation or flicker like it is supposed to.
Any recommendations?

[booj]

Check your cathode bypass caps for V5. The circuit is similar for both amps except for the 8uf cap in the 270 vs a 25uf cap in the '71 amp. The 270 also has a .022 cap across the 10 Meg resistor. Very nice for lessening the tremolo ticking that happens in the later designs.

[tonalvision]

checked

I am using a AA 270 schematic and "layout" wiring diagram from schematic heaven. My drawing has the 25 uF in that position. Don't see an 8 uF cap in the schematic off v5. Another change in my 1971 is the .02 uF cap off pin 1 does not connect directly to the .01 uF cap like it does in the drawing. I had jumpered those with a wire to make them agree with the layout of the diagram. When the vibrato stopped working, I removed the jumper. Layout shows a 25 uf cap across the 2700 ohm resistor (off of pin 3 of V5) which was not present when I started. (I added one.) The 100k resistor off of pin 8 of v5 has a 5uF- 25v cap across it (on the layout and in my amp.) The schematic section for V5 seems to show a 25 uF should be across the 100k resistor. It doesn't appear that the schematic and/or wiring diagram are current to my amp. One more thing, The cap that comes off pin 5 of V5 to the ground of the vibrato pedal jack, (ground) is not on either of my drawings. Thanks for taking the time to read.

[booj]

Twin Reverb Amp AA270 Schematic.pdf

Twin Reverb Amp AA270 Layout.pdf

Maybe this will help

[Jazz P Bass]

Twin Reverb Vibrato

The 0.02uf cap coming off of pin 1 must connect to the 0.01uf cap.
This common point must be terminated at the speed pot with a 100K R to ground.
Make it like the schematic, then troubleshoot it.

[tonalvision]

solved

Looking very closely, I discovered that I reinstalled one of the .01 mfd caps across the wrong eyelets. Moved it and it works again. Almost afraid to go farther but I would like to improve vibrato because the intensity is not as intense as other bf and sf fenders I own and have owned. It is OK though. What I would really like to improve is the volume. it has low volume for a twin. It will get loud, but it is no louder on 5 than my DRRI on 3. I am thinking that screen resistors could be a problem. Any suggestions as to where to look first. I have new electrolytics in it. This is an amp that I paid a very reasonable price for and want to use to learn from it. I have done more to this than any other AB763 type to date. I have messed with Bandmaster, Tremolux, Deluxe Reverb. Thank you gentlemen for your willing assistance.