Building the Uglyface PCB

[4floorsofwhores]

After having shelved this one for over a year, I finally finished it. Upon switching it on, I had the same reaction as many. I heard a loud howl and hum and thought, "Man! Another one for the scrapheap." Then I played a couple of notes through it, adjusted a few of the knobs, and realized, "Hey! It's actually working!"

Thanks, Taylor! Great PCB. Fun build and very happy with the results. My first successful pedal build in a while.

Actually, I couldn't unplug this thing for at least 45 minutes after plugging it in, Too much fun! Still need to box it up. Don't know if I've got the guts to do anything as complicated as the Gristleizer  yet, (hell, when I reach that point I'll be able to handle the Sub-Commander) but this thing makes sounds that definitely get you into Throbbing Gristle territory. I'm curious about the Christine now. Any similarity to the Uglyface? I like my discordant noise.

Cheers and thanks for such a nice PCB Taylor!

Dude i'm pretty new to electronics too but the gristleizer is a lovely simple build. Christine is wonderful and about as easy to build as the uglyface. Make sure you get the mental chip if discordant noise is your thing I''m currently attempting to put gristleizer, uglyface with lfo mod, christine, delay and synthacon filter in the same box. It willl be the basis of my sound

[DelSpanisho]

I successfully built mine, and sounded great, but when I tried to add an LFO to it it the LFO didn't work, and if the LFO wasn't switched on the IC's would run super SUPER hot and start to smell. 

 

This is the LFO I'm using:



I've unsoldered the wire going from the LFO switch to 386 pin 5 to avoid the heating issue, but now the pedal sounds awful. Any info as to how I can successfully implement an LFO with this PCB?

[mwynwood]

Hi everyone,
I've just started building an Uglyface with the PCB from http://www.musicpcb.com/

I was wondering about the Vactrol...
The documentation asks for a VTL5C3.
I don't have a VTL5C3, but I do have a VTL5C4/2.
Is the VTL5C4/2 suitable? Will I need to put a resistor in series or something?

Here's a datasheet I found:
http://www.excelitas.com/downloads/dts_vtl5c3c4.pdf

Thanks for your help, I don't know much about vactrols!

[duck_arse]

the 5C4 has a faster response than the 5C3, and a lower on resistance. both of those facts may be useful, or not. the biggest diff is the 5C4/2 has a dual ldr. this might be usefull to you, as you can switch between a single half, the whole in series, or the 2 in parallel, each giving different resistance range responses.

[chemosis]

my sensitivity knob stopped working after one day so and now I get no envelope sounds. no lazer sounds. no wah sounds. I used lm386. I had this issue months ago with a ugly face I bought and therefore sold it very cheap to a friend that wanted it. I also know that a lot of people are having this same problem just wish there was a solution. maybe my lm386 stopped functioning properly. maybe I should of used the JRC? could this explain why this keeps happening to people??? or not?? I doubt this many people all got bad vactrols and a lot of people seem to have this issue I had it with 2 ugly faces.

[chemosis]

PLEASE some one SOLVE THIS ISSUE. peoples sens knobs are not working right. it seems to be common and theres got to be a solution. im just wondering if its from using different 555 timer chips or he lm386 instead of the jrc

[Taylor]

As I've said through email, using the actual chips specified in the document is of absolute importance in this circuit. Until you get the correct parts in your build, you can definitely expect weird results with this effect, including exactly what you describe. People have been building this circuit successfully for nearly 15 years, and there's even a boutique pedal company who sells this exact circuit, using a PCB that is a trace-for-trace clone of mine, commercially. I hope this doesn't come across as rude,  I've really tried to be helpful here, but only you can solve the issue by using the correct parts. The problem lies not with the circuit or the PCB. I agree that it's a finicky build, but there's no sense "looking for a solution" when there already is one.

Once you get all the parts specified in, let us know if you're still having the same issue. Only then can anybody give any helpful advice.

[belyheart]

I just made two uglyfacse and the first has no problems and now I made another and it's having issues.  I used the Xvive VTL5c3 and an LM386 for this one.  The first one I made the other day I used a Vactec VCL5C1 and JRC386.

Issues
When engaged the volume drop is tremendous, the volume knob works, the frequency knob seems to do something but not much, threshold doesn't oscillate and it's too quiet to tell if the sensitivity knob is doing anything.

The other uglyface I made years back with a LM386 and it works as it should.  So I think maybe the vactrol is the issue.  The Xvive has a + on the top and I have it faced down with the + matching.  The notch on the side of the vactrol matches that of my previous builds so I'm unsure what it could be actually. 

[Taylor]

The output of the circuit that we actually hear is the 555 chip. The 386 and optocoupler only have to do with sweeping the frequency of the 555 oscillator around. So I'd start by looking at the 555 to see why the output is low - did you use the ICM555?

If you haven't yet, use an audio probe and poke through the circuit, starting at the input. Check the signal at pin 5 of the 386. Also check with a multimeter the power at pin 6 of the 386, and pin 8 of the 555 to make sure those are around 9v.

[belyheart]

I used a TLC555CP, which has the same pinout and seems to be the same overall from the other one I used which was a TS555CN.  I'll try this audio probe thing out and report back with results.

Both chips are getting 9.3 v according to the multi. I did notice the chips are both very hot. I may have a bad joint the chips may not be in all in.

[duck_arse]

neither chip should get hot. pull them from their sockets and measure the voltages on the empty pins.

[belyheart]

After removing measuring and placing the ICs back into the circuit, the heat doesn't seem to be an issue so maybe they were slightly off.  I accidentally soldered the IC sockets w/the chips on them and wonder if the chips are the issue.

The audio probe seems to make sounds from 1,8, and 5 (386)that are distorted but low in volume.  I'd compare to the previous box I made, but I no longer have it.

Here's volts for the the chips

555
1.          8. 9.35
2. 9.15   7. 9.25
3. 9.25   6. 9.15
4. 3.52   5

386
1          8
2          7
3          6. 9.35
4          5. 3 (starts around 3 and goes down at a decreasing rate)

[belyheart]

Still haven't figured it out at all.  Very frustrating.  Anyway to tell if the vactrol is the issue?  I think I put it in right, but what could be doing this?

I now have a bypass signal and no signal when engaged.

[Taylor]

The vactrol looks like it's in right. It seems like the 555 is just not oscillating. Here's a thread where Tim talked about inconsistent results with any chip other than the one specified:

http://www.diystompboxes.com/smfforum/index.php?topic=49569.5

The TLC555's datasheet says it has a CMOS-compatible output, and that it's made with "LinCMOS" technology, but it's not clear to me whether that actually means it's a CMOS part, and I can't find any info online about what this LinCMOS process is.

So, that would be my hunch, assuming you've reflowed your solder joints and are sure there's nothing out of place on the board or wiring. Try poking around the 555 with your audio probe and see if you find any sound anywhere. Sometimes I'll also use my multimeter on the continuity setting, to check that all the grounds are connecting but also that the signal isn't shorting to ground anywhere (long wire leads touching on the other side of the board, for example.

[belyheart]

That's weird since I've used that chip for all previous builds.  I've moved on to something else at the moment.  I think I should build a beavis board and unbox it and see if it still works.  I'm wondering if I fried an IC since I soldered them attached to the socket.

[blackieNYC]

The chips can take soldering iron heat, for the usual amount of time. (Happens millions of times per day!)
It's difficult to get help on this - if it were a fuzz face and it was making this or that kind of sound folks would spot it for you quickly. The voltages will help.

[belyheart]

Well I replaced both chips and it works fine.  Not sure what happened, but glad they were socketed. 

Don't know if I got duds or something I did made that happen.  I'm guessing based on the heating issue I was having that it was a loose connection and then they fried.

[Taylor]

Glad it's all sorted!

[rankot]

If you need to check vactrol polarity, simply take DMM and put probes on vactrol's LED wires. Now check the DMM for diode measurement and if you measure some voltage drop, then black probe is on LED- and red is on LED+. If not measuring, try to switch, and if no measure even then, the vactrol is gone

[telebiker]

Sorry for bumping this thread, but I'm a bit stuck with one thing related to this PCB. Probably someone has ideas how to investigate this properly.

I'm using a musicpcb.com plate and trying to add LFO according to the diagram:



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: http://www.madbeanpedals.com/forum/index.php?topic=10370.0):



Does this layout to add LFO make sense at all?

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.