UglyFace + LFO

[LaceSensor]

Not been posting many reports recently.
That might change, starting with this.

Its the MusicPCB.com UglyFace PCB, with the additional LFO (thanks Juansolo for the layout).
This is a really cool pedal, people call it the poor mans MicroSynth and I can appreciate why.
The LFO is pretty versatile too, it can cycle as one would expect for almost auto-wah sounds (but obviously very fuzzy, given the nature of the beast) but can also go really fast for proper lazer bleeps. The ramp up and ramp down offered by the 3 way SPDT on/off/on are also really usable.

All in all a great effect, nice PCB. Pads a bit smaller than we are accustomed to with Madbeans stuff, but it was still an easy build due to the small number of parts. I added a dual colour LED to show between envelope and LFO modes when on. Mods were 50kA for the Volume and 250kB for Frequency.

Anyone that likes noisy fun and synthy sounds, build one!

[calciferspit]

NICE! I built one of these on the Musicpcb and I love it. I added a voltage starve to mine which increases glitch and sub octaves in the sweep as well as taming the oscillations. I think I'll try an LFO on mine.

[muehring]

Cool build.  Is the LFO layout posted anywhere?

[LaceSensor]

It is now...

Using the Music PCB board I didnt need C3, and youll see from the pics I used a trim for depth. its a set and forget thing, no need for external pot in my experience.

[muehring]

Nice, thanks!

[juansolo]

It is now...

Using the Music PCB board I didnt need C3, and youll see from the pics I used a trim for depth. its a set and forget thing, no need for external pot in my experience.

Yeah, I fit a trimmer there also now.

If you fancy doing it all on one bit of vero it's here:



Worth using a stomp for the LFO as Lace has. You can also have a flashing LED if you drive it from pin 1 of the LFO

[muehring]

Sweet, vero's even better.  Thanks!!

[Rip57]

That is SO CLEAN!

[Jaga]

I would like to build the same circuit. Since I'm having the same PCB from musicpcb, adding LFO looks one of the must have things. However, I don't have a veroboard, just a regular perfboard.

I've redrawn diagram to fit to perfboard. It's the same (just omitted "sensivity" pot since it exists on the PCB), but second look always worth it. In this example it would fit 6x15 board (can be even smaller). Would be grateful if someone could notice obvious errors. Will report once I have some news regarding the build.



P.S. Sorry for bumping this thread.

[Jaga]

Hello!

I would be really grateful if someone could give some ideas what can be wrong with my build. Actually, I'm building an Uglyface using musicpcb plate, and I'm also adding an LFO as described here. I'm stuck and don't understand why the LFO is not working.

The interesting thing that I've done LFO part twice and each time it didn't work. However, LFO was working on my 1st attempt for several minutes. Suddenly it stopped, but I can't figure out what changed.

What can be wrong? What should I check firstly? I'm not sure how to debug this and if audioprobe helps here. If some photos are required I can attach them.

Thank you.

[Jaga]

 I'm a bit stuck with one thing related to the same build. Probably someone has ideas how to investigate this properly.

Since sensivity pot already exists on musicpcb pcb, I used injection points like this (I have also omitted C3 cap as it was advised here):



Doesit make sense at all, or I missed something?

I have the following voltages:
1. Sensivity pot point; LFO on: regularly varies 3.2–5V (that's a sign that LFO works)
2. Sensivity pot point; LFO off: static 5.5V (that's expected I believe)
3. 386 Pin 5 point; LFO on: very slightly varies randomly around 5.632V
4. 386 Pin 5 point; LFO off: very slightly varies randomly around 5.602V

I cannot hear any LFO applied on wet signal for some reason. The curious thing is that LFO worked for some time once I have built the circuit, but then it stopped and I can't figure out what changed.

Would be grateful for any help.