Tremulus Lune problem

[nicobenny]

Hi everyone,

I just finished building a 4 knob Tremulus Lune tremolo using Tagboardeffects's vero board layout.
When on, the status LED blinks and its blinking varies with the speed knob, as it's supposed to but on the board, the LED/LDR assembly seems to have a liitle problem and I get no Tremolo effect.
The LED in the LED/LDR assembly isn't flashing. It stays on all the time.
I can change its brightness with the Depth pot but the speed pot doesn't have any effect on the LED.

Any suggestion of what I should be looking for?

Many thanks!

[Kevin Mitchell]

The *input* of the depth pot is not connected to the output of the oscillator's buffer. If it were, both LEDs would flash - not just the status LED. Notice how the + pin of the status LED shares the same connections as the depth pot?

[nicobenny]

I just checked the connections from the LED in the vactrol and the depth pot. They seem fine...

[Kevin Mitchell]

I just checked the connections from the LED in the vactrol and the depth pot. They seem fine...

It wouldn't make sense for one LED to flash and not the other if they have the correct connection.

Maybe post a photo so extra eyes can validate.

[Kevin Mitchell]

Both the status LED and the opto LED are the same circuit coming from the buffer though the opto LED has the 1K depth pot & resistor acting as a pull-up so you can control how dark the LED can go for more intensity/depth.

[nicobenny]

Yes, indeed. I can't seem to find out where I might have made a wrong connection.
I'll post a few pics tomorrow, it's getting late here, I've already spent way too much time on this today and my head is not very clear anymore...

Thank you very much for your help so far, Kevin!

[Andrekp]

I don't remember the details, but I seem to recall that when I made MY Tremulus Lune, I used a roll-your-own Vactrol and had to tweak the resistor values in the LED circuit to get the effect I wanted.  Remember, the point here is making the Vactrol resistor do what it needs to do, so you need to tweak the LED brightness and on-off response to make that happen.  IME with these roll-your-owns, you need to consider the schematic just a starting point.  (And I used that same layout as you did).

Andre

[nicobenny]

Hi there,

I got my Tremulus Lune working!
After testing, the culprit happened to be a bad solder from a wire going to the depth pot!
The pedal sounds very nice and has a very cool vibe to it!! Really recommended tremolo build.

Thank you Kevin Mitchell and Andrekp for your help!

[Kevin Mitchell]

HAH! Called it 

Enjoy!

[nicobenny]

Actually, it turned out that my depth pot had a defective leg!

Trashed that piece of crap and replaced it with a good old Alpha pot!

[Andrekp]

Glad you got it working!

I don't recall if that layout includes the pulse width mod, but you should add it if it does not.  Very useful.  More useful than the fine tune.