NEW BUILD ISSUES AB763 SUPER REVERB

[SMPL]

Normal channel working great! Vibrato channel volume week and no vibrato effect drive nor intensity do not work. Check out the pics and see if any of you see anything obvious that I missed. I am a new builder and need some help! I appreciate all of you. I do get 400 volts at V5 pin 6 and 460 volts from the power supply to the Optocoupler. I am using Mercury Iron. The reverb works fine.
Cheers. Shawn

[Firestorm]

Make sure the leads from the LDR side of the "trem bug" aren't crossed. If they make contact with each other, it will ground out most of your signal all the time.

[SMPL]

I purchased the Optocoupler from Antique electronic supply and think I wired it correctly but do not know how to test it without removing it. Is this the suspect part?
Thank you, Shawn

[Karl]

The Vibrato doesn't work without the footswitch connected. You can make a RCA jumper if you don't have a footswitch.

[SMPL]

Karl, Thank you for the info. I did the bypass and still no Vibrato. I appreciate you input though!
Thanx, Shawn

[Karl]

Do you have a photo showing the backside of the intensity and speed pots?

Are the pots both grounded properly?

Can you post the voltage readings on the vibrato tube?

[Firestorm]

The AES bug works fine. You need to be able to tell which side has the neon bulb leads and which side has the photocell leads. The neon bulb gets connected to the 10M and the 100K. If you got it backwards, it might have fried the photocell (not sure, but could be).

If that's connected right, you may have a problem with the oscillator circuit -- it may be possible for the neon bulb to be on all the time, in which case you'd be grounding out the signal and the whole channel will sound very weak. Check your connections on everything in that circuit. Or just unsolder the neon bulb legs from either the 10M or the 100K. That will shut off the bulb. If that gives you good volume on the channel, the problem is the oscillator circuit or the bulb itself. If not, the problem is likely the wiring of the Intensity pot, or the wiring of the photocell leads (like I said, the two leads on that side can't touch).

[Karl]

There is a grey dot on the neon bulb side of the optocoupler.

Check the ground connection on 100k resistor connected to the speed pot. This ground connection must be connected for the oscillator to work.