Abyss Univibe - tone is off

[Jdilly]

Hi. I just finished my 3rd Abyss build. When I plug it in and engage the switch, the strobe lights up and the LED works, but the sound is more like a tremelo pedal vs a Univibe.

This is before it’s been boxed.

Here’s a clip

Any ideas?

 

[digitalyeti]

Since the Abyss works with LDRs, it needs to be boxed to work properly. LDRs are resistors that react to light and need to be in the dark to work properly. Since the pedal is not boxes, these LDRs are always receiving light and so not working as intended. I am not saying your pedal works, but you cannot knows unless you box it or find another way for it to run in true darkness.

 

[Jdilly]

Thanks for the reply @digitalyeti . I tried boxing it up, to keep it dark, but it’s still very tremelo sounding, and missing the “vibe”.

 

[zgrav]

you may not be getting a dry signal mixed with the wet signal -- that is the difference between the two sounds. you obviously have signal going through the pulse path, so use your DMM to see if you have continuity from IC1, pin 1 to R14, from R14 to IC1, pin5.

Do you hear changes in the sound when you are adjusting the Throb and Voice pots? Intensity?

 

[Jdilly]

I'm getting continuity from IC1, pin 1 to R14, and from R14 to IC1, pin5

Throb and Voice pots don't seem to be doing much (if any). Intensity works, but I notice when I crank it full to the right, the tremolo sound goes away. Once I dial it back, the tremolo comes back.

 

[zgrav]

Given that things are kinda sorta working but not well, I suggest following the general advice -- post detailed pictures of both sides of the board that are clear enough to check the part values. then others can assist while you verify the parts values are correct yourself.

Do you have one of the other vibe pedals you built for comparison?

 

[Jdilly]

@zgrav @digitalyeti I'm a knuckle-head. Just saw that one of the ICs was upside-down.

I popped a new one in and all is well with the universe (so no need for solder wick or jumpers). Woo hoo!

Thanks so much for the replies and assist.

 

[zgrav]

did you test the IC that was upside down? there is a possibility it is still OK.

glad you spotted what needed to be changed!

 

[Jdilly]

Yeah. I flipped it and it didn't work. I had a bunch of spares though