VT-Phasor Twin Tremolo

[Helmholtz]

Again, what is the LED you have?
Datasheet?

[bobloblaws]

Again, what is the LED you have?
Datasheet?

I'm trying to determine if the LED inside the dome is faulty or not. Are you asking me about the random LED I used for testing as in post #7 etc?

[g1]

I think it is the original stock LED you have in there under the dome, correct?
In the early posts there was talk of a LED but you had not even removed the dome yet so that must have been some other LED for a different function.

[Helmholtz]

I'm trying to determine if the LED inside the dome is faulty or not.

I wasn't aware that you still have the original LED inside the dome.
Can you even see if it flashes?

[bobloblaws]

I wasn't aware that you still have the original LED inside the dome.
Can you even see if it flashes?

That's correct, I was not able to remove the dome. There is a couple of pinholes in the top of the dome, but as of yet I have not been able to detect any light. I've been holding out hope that the LED is OK based on the fact that it seems to check out with the diode checker on my DMM. It shows 1.5V (which would be the forward voltage if I'm not mistaken) and O.L. if I reverse the DMM probes. This is similar to what I generally see when using that function on LED's and other diodes, hence I've hoping the LED itself is not my issue.

[Helmholtz]

Not clear. Does that mean that you don't know if the LED flashes or not?
Does the substitute LED flash if you connect it instead?

[bobloblaws]

Not clear. Does that mean that you don't know if the LED flashes or not?
Does the substitute LED flash if you connect it instead?

I mean that to this point I have not been able to detect any LED activity through the pin holes. This is from post #8:

A typical LED roach will control only one LDR.
Also the LDR resistance might not be suitable for the circuit.
I'd connect a red LED (observe correct polarity) and see if it flashes.

No illumination or flashing happening with the red LED. I do know there is some oscillation happening and the pot is increasing/decreasing the rate (I've heard it as a clicking sound when I've been probing around).

[Helmholtz]

I mean that to this point I have not been able to detect any LED activity through the pin holes.

Would you be able if there was any?
Did you try in complete darkness?

No illumination or flashing happening with the red LED. I do know there is some oscillation happening and the pot is increasing/decreasing the rate (I've heard it as a clicking sound when I've been probing around).&#8203

Did you try shorting C and E with the red LED?

[J M Fahey]

Beyond proper voltages , you should see the LED blink, that´s essential for Phasor operation.

Tremolo here is just a sub-function of Phaser so you first need it to work.
FWIW this is the original Univibe arrangement:



and a modern version:



both must be used inside a light tight and reflective cover, of course.