Uglyface troubles

Bard Morons · May 09, 2007, 03:45:53 PM

I just finished an uglyface circuit and it is not acting quite as it should. I am getting a harsh fuzzy distortion as I imagined I would from hearing sound clips, but I am getting nothing more. It appears as if the envelope filter is doing nothing. I'm using the blend mod and both the volume pot and the blend pot work just fine. However, the frequency, sensitivity, and threshold pots do absolutely nothing. I have checked my wiring and it appears all pots are wired correctly and I cannot spot any errors in my soldering on the perfboard. If anyone has any ideas of what might be going wrong here, I'd greatly appreciate some thoughts. Thanks guys.

oldrocker · May 09, 2007, 06:19:48 PM

Sensitivity is directly associated with the optoisolator. The LED part specifically. Are you using a Vactrol or a home made LED/LDR? Double check the polarity of the LED.

Bard Morons · May 09, 2007, 09:24:51 PM

Yep, that was my first thought too. I'm using a vactrol and the polarity appears to be correct as it's marked directly on the vactrol. I will have to check again to make sure, but I've gone over that a few times. Thanks though, and that certainly seems to be the logical problem... hmm.

zzallin · May 09, 2007, 09:31:14 PM

Is there any disadvantage to using a pot in place of the Vactrol?

Zack

oldrocker · May 09, 2007, 11:05:27 PM

I had a Vactrol labeled wrong right from the supplier. I took me forever to find that. I never dreamt they would have it labeled it wrong but they did. When I swapped the leads it worked. I'm not saying that's your problem too but it did happen to me. For my Ugly face I made my own LED/LDR and it sounds great.

oldrocker · May 09, 2007, 11:12:47 PM

Zack, the Vactrol is used as a frequency shift when the guitar is strummed for an automatic sweep. A pot would have to be manually turned so you would need a foot controller of some kind to get it to sweep.

Bard Morons · May 09, 2007, 11:38:27 PM

Wow, I hadn't really thought to check out the validity of the markings. That is quite interesting. Tomorrow morning I will definately have to see if that is in fact my problem. Thanks for the tip and I'll have to let you know how that goes.

ambulancevoice · May 10, 2007, 02:22:39 AM

the vactrol is just and enclosed led and ldr right?

Bard Morons · May 10, 2007, 07:49:48 AM

Yes sir, that's all it is.

Bard Morons · May 10, 2007, 09:29:49 PM

Okay, I finally got around to checking that. I resoldered the led part in reverse direction and I'm much closer to the expected sounds. I'm getting a cool synthy octave down effect, but I'm still not getting an envelope type sound. It sounds like it may be muffled in the background, but it is certainly not pronounced at all which is very odd. Also, I thought the frequency pot covered a very large range in pitch? Mine keeps it very, very similar almost like it is stuck, although it is slightly changing. I'm closer, but I'm obviously missing something. I'll give it a run over in the morning, but I just thought I'd update and say thanks thus far.

oldrocker · May 10, 2007, 10:41:42 PM

One of the reasons I make homemade optoisolators is the amount of effect. Are you using VTL5C3 or VTL5C5? I found a separate LDR with resistance of about 200K and yellow LED works nice with the Ugly Face. I found some vactrols weak most likely because of thier resistance value.

Bard Morons · May 11, 2007, 07:34:17 AM

I'm using the VTL5C3. Perhaps I will have rig up my own optoisolator. Obviously the one I'm using is not doing its job very well. Thanks for all the advice oldrocker. I appreciate it. Once again, I'll let you know how the rigging goes.

FisTheGoon · May 11, 2007, 11:31:41 AM

I built this UglyFace with diy optoisolator.The frequency shift is funny not dat smooth.Maybe need to put more than 2 shrinkwrap on it or follow what Mr. OldRocker suggest "LDR with resistance of about 200K and yellow LED".

oldrocker · May 11, 2007, 11:31:54 PM

You can checkout the sound sample of my Ugly Face on my website or the BasicAudio sound sample website. I added some newer samples of a few effects on my website.
FSH-1 Sample and Hold
Nyquist Aliaser
SG-1 Slow Gear
Bit Crusher
Rebote Delay (Original Version)
Phuncgnosis auto wah

http://randallbarnett.homestead.com/SoundSamples.html
http://www.mrdwab.com/john/soundclipspage.html

Bard Morons · May 12, 2007, 04:27:36 PM

Finally! I went and put together a good old yellow LED and a photoresistor at about 200k (give or take). Works nicely now. Sounds horrible! Just what I was looking for. I'd have never thought at the start that a vactrol would be the problem, but I learned a lesson. Thanks oldrocker for the help and thoughts. Oh, and I really like some of those sound samples.

oldrocker · May 12, 2007, 05:40:46 PM

Hey!! I'm really happy you got that going. I love the Ugly Face and it's one of my favorite wacky effects pedals.
It's a trip to think that a company wouldn't test what they're manufacturing to make sure things are labeled correct. What ever happened to quality control? But I'd rather make my own optoisolators anyway. That way you can pick and choose the sensitivity of the components you're using and experiment.
Thanks for checking out my samples site. I know the guitar playing isn't much but hopefully you can judge from the samples wether you'd want to build a specific stompbox form that site.
Have fun messing with your synthy U.F.

News:

Uglyface troubles