Traynor YCV-40 No Reverb

[ca7922303]

U1 pin#5 & #7 have 12V.

With input jack isolated from chassis there are no volts @ U1 pins 5 &7 and all pins within red circle have signal. With input jack touching chassis, there is 12V @ U1 pins 5 & 7 but about 1/2 of pins in red circle have no signal.

[Helmholtz]

Reverb return jack should be grounded (why did you remove it from chassis?).
And U1 needs to have 12V at pin 5 and pin 7.
You should see signal at pin 7 (output of opamp) and on both ends of C12.

[ca7922303]

Reverb return jack should be grounded (why did you remove it from chassis?).
And U1 needs to have 12V at pin 5 and pin 7.
You should see signal at pin 7 (output of opamp) and on both ends of C12.

I was talking about the main input jack where instrument plugs in. I had signal at all pins of components in red circle until I started reinstalling chassis. Last thing I installed was the main input jack and that caused about 1/2 of the pins to not have signal. I isolated main instrument input jack from chassis and all signal returned. I have tested reverb tank with all pins having signal and with 1/2 of them with no signal and still no reverb. Two things I have noticed during all this, I can get crashing noise from tank with RCA cables installed either way and when reverb control is on 10, instrument volume noticeably decreases, but still no reverb. Also, all Resistors inside of red circle G1 sent me, tested at correct value per schematic in circuit. Is in possible that R68/69 can be a correct reading without one leg removed @ 59.2k. Appreciate your help.

[ca7922303]

Reverb return jack should be grounded (why did you remove it from chassis?).
And U1 needs to have 12V at pin 5 and pin 7.
You should see signal at pin 7 (output of opamp) and on both ends of C12.

U1 has 12V @ pins 5 & 7 and there is signal at pin7 and on both ends of C12 from a signal generator and using a dmm on audible continuity setting.

[g1]

Connect the input jack to chassis, it is just confusing things. There should not be signal at all points in that circled area, just the parts that are in the signal path.
Do you still have signal at pin7 of U1 with input jack connected to chassis? Can you hear the tank when shaken all the time now?
If so it is time to move back to the drive side of circuit.

[Helmholtz]

U1 has 12V @ pins 5 & 7 and there is signal at pin7 and on both ends of C12 from a signal generator and using a dmm on audible continuity setting.

You can't find/measure a signal in continuity setting.
Signal is AC voltage.

[ca7922303]

Connect the input jack to chassis, it is just confusing things. There should not be signal at all points in that circled area, just the parts that are in the signal path.
Do you still have signal at pin7 of U1 with input jack connected to chassis? Can you hear the tank when shaken all the time now?
If so it is time to move back to the drive side of circuit.

I phrased that wrong, there is signal within red circle you sent me of components in the signal path, yes.And yes, the reverb tank does make noise all the time now. I will check for signal now from the send jack. Also, there is signal @ u1 pin#7 w/input jack connected.

[ca7922303]

You can't find/measure a signal in continuity setting.
Signal is AC voltage.

Using a signal generator and a dmm set on vac, with power on(amplifier), all points in both signal paths(U1 & U2), produce signal. Is the thing with the input jack looking like a ground issue somewhere?

[Helmholtz]

It would really be helpful to see a full schematic.

Also pictures of input and reveb jacks might help.

[ca7922303]

It would really be helpful to see a full schematic.

Also pictures of input and reveb jacks might help.

Schematic

[ca7922303]

It would really be helpful to see a full schematic.

Also pictures of input and reveb jacks might help.

Photos with board installed

[Helmholtz]

Thanks.

I understand that with the input jack properly grounded the amp works fine with dry signal, but no reverb.
Do you get a reverb drive signal at U2 pin 7 and on both ends of C9?
Can you see a signal at the reverb cable plug when disconnected from the tank input (i.e. with the send cable connected to reverb send jack at amp)?
With this reverb cable connected to tank but not to amp, please measure resistance at the open plug.

[ca7922303]

It would really be helpful to see a full schematic.

Also pictures of input and reveb jacks might help.

Photos

[ca7922303]

Thanks.

I understand that with the input jack properly grounded the amp works fine with dry signal, but no reverb.
Do you get a reverb drive signal at U2 pin 7 and on both ends of C9?
Can you see a signal at the reverb cable plug when disconnected from the tank input (i.e. with the send cable connected to reverb send jack at amp)?
With this reverb cable connected to tank but not to amp, please measure resistance at the open plug.

Open plug connected to input of reverb tank measures 72 ohms, signal at u2 pin#7, both ends of C9, and cable connected to reverb send jack at amp.

[Helmholtz]

Unfortunately the pictures don't give a clue.

Measurements look good.

If you look at the reverb springs inside the tank, can you see anything that could prevent them from freely vibrating (actually they are twisting)?