Last Vibro King question..I promise

I got the amp working and I think it sounds great! Now the vibrato doesn't work.

The cells are not lighting anymore.

Any suggestons on how I should test?

This mod should have been nowhere near the vibrato circuit...

Thanks again,
Paul

 

Hi Fullerplast,

Thanks for all the help BTW. I really appreciate it.

I tried the footswitch. It works for the fat boost function but does not work for the vibrato. When engaged it just makes a pop. I should note when I turn up the intensity, you can hear the amp volume go down. I would think this would indicate that the vibrato circuit is still in the loop.

I wonder if I blew the optoisolator or if it just ran out of life....seems a little too coincidental

 

Thanks for responding Fullerplast..Not yet. I've been a little limited in time lately (New baby). I did try swaping the 12AX7's, no luck. I'm going to see if the lamp is getting voltage and work my way back.

If I opened the circuit in the footswitch so as to make it impossible for the tremolo to be engaged (bad soldering). Would the lamp still be pulsating, just out of the audio path?

In other words. Is the lamp ALWAYS pulsating?

Thanks,
Paul

 

darn,
I measured the plate voltage on v6 A and B to see if there was a swing in voltage. Steady as a rock..There is also voltage present at the bulb side of the roach. The bulb does not work however.

What actually makes the bulb blink anyway?

Thanks,
Paul

 

Hi fullerplast.
I may have to do a little more digging. I'm still struggling with the schematics but learning a lot as I go.

If I follow the physical layout, I see R58 going to r57 going to the foot switch. The other side or R58 goes to CB5.

If I follow the treble pot, The center post goes to R68 then to C11 then to pin 6 of v5.

Did they goof the schematic?

I did replace r58 with an 820 ohm. Should it have been R68?

Thanks,
Paul

 

I went to fender and had to blow up the schematic like 200% but I think that's where I goofed. I'm going to be heading to the electronic store on my luch hour tomorrow. Can anybody tell me what R58 should be???

I can't find it on the schematic and wouldn't be sure I could read it accurately id I saw it.

Thanks,
Paul

 

Yeah, I did......oops. I guess I should start by fixing that .....

 

WOOHOOO!



She is working now!. I have to spend a little more time at volume to make sure everything is cool but I thing we found it!!

Thanks again Fullerplast, Yo da' man!