Uglyface info required

big bustle · May 09, 2008, 01:32:02 PM

i'm finaly starting to build this today and i cant find any of my 1n914 diodes.

will 1n4148 be an ok sub?

John Lyons · May 09, 2008, 01:49:07 PM

Yes, pretty much any silicon diode will work.
1N914, 1N4148, 1N916, 1N4001 ,2, 3, 4, 5, 6, 7 etc etc.

Mick Bailey · May 09, 2008, 04:34:37 PM

I originally breadboarded the circuit with 1N4148 but had a lot more 1N914 so I used those instead in the final build and kept my 1N4148s for another day.......

No difference in function or sound.

big bustle · May 09, 2008, 05:10:32 PM

went with 1n4148.. hooked it up to a working ugly face and... the freq sweep has changed and while it does track the gtr there's a but load of noise all over it.

i used my layout on perf and i cant figure out whats wrong.

i checked continuity between plus 9 and ground to r1 and 2 and it shows a short. is that correct for a multi meter to read a short even if there are 2 470k resistors between the two circuit points?

Mick Bailey · May 09, 2008, 05:25:03 PM

Looks like you have a problem there - are you reading shorts across both 470k resistors when you measure them individually?

Someone else posted that they've built the LFO to drive a commercial pedal and have it working successfully so I think the schematic is OK.

big bustle · May 25, 2008, 12:53:26 AM

this is probably completely irresponsible of me to post this as this theory has been untested... but there's chance someone else has had the same problem as me... so take this with a grain of salt if you haven't tried mick's appreciated hard work with the uglyface yet.

so my ugly face was working fine. i added the lfo circuit using the layout i made and it didn't work. now the envelope does not work after completely removing the circuit. i've checked each trace and i'm thinking there's a chance that the lfo blew out the led in my vactrol.

i haven't replaced it in the circuit yet to know which is why this theory is untested. i hope i'll have time to do that in the coming weeks. as of now i figured i'd post this to see if anyone else had this problem.

Mick Bailey · May 26, 2008, 12:41:45 PM

Sorry you're having problems. R6 is in there specifically to limit current to the LED. The voltage is also dropped across the 1k pot which shunts the LED, giving further protection. You can independently check the LFO is working before you connect up to your Uglyface by connecting the output to an LED shunted with a 1k fixed resistor.

Someone else has built the circuit as a standalone;

http://www.diystompboxes.com/smfforum/index.php?PHPSESSID=f043ba193ba7aa7b4ea6fb16619e09c4&topic=67453.msg537983#msg537983

soggybag · June 04, 2008, 04:12:06 PM

I have been playing around with the UglyFace Lately and came up with a use full mod.

I find the range on the oscillator goes from medium low to ultra high. The high end is not very useful to me musically. Changing the cap from 7555 pin to ground to .47 moves the range from about the low E on guitar to just off the end of the fret board on the high E.

snarblinge · June 09, 2009, 11:15:12 PM

Have Been collecting the bits to build one of these, Has anyone build with a standard Optoisolator IC? any reason I should not other than price, there's less than a dollar difference ind would avoid the isolation issues.. opinions please.

also are there any mods not listed in this thread I should include or consider including??

churs all

igor12 · June 10, 2009, 12:20:31 PM

breadboarded the LFO mod and it works terrific. I don't know if I like it though as it kinda makes my uglyface sound likae a phase shifter. That's just my opinion though.

kurtlives · July 25, 2009, 06:36:08 PM

I just built the Uglyface with added LFO mod.

I am having some bleed issues though. Even with the LFO switch off I get a oscillating sound, it's somewhat soft sounding. With the whole circuit bypassed and the LFO engaged I can hear it cycle through and it bleeds.

Otherwise the circuit works great! Should I try grounding the output when bypassed?

Mick Bailey · July 26, 2009, 10:20:26 AM

The LFO switch cuts the power to the LFO to prevent it from modulating the power supply when turned off, so it can't be the LFO making the noise unless the switch wiring has a mistake. Make sure that in the LFO 'off' position there is no power to the LFO IC. The bleed-through in bypass mode may be lead dress. Mine is completely silent when bypassed.

FisTheGoon · July 26, 2009, 11:24:05 AM

Quote from: andrew_k on April 25, 2008, 04:20:42 AM
This layout isn't yet verified, but I've gone over it a couple times and will be building it as soon as I have the parts, possibly this weekend.
If anyone sees anything out of whack, please let me know.

Mick: I haven't included your volume mod (should I? I guess so..) but I've included the other mods form your schem.

Regarding the layout Andrew,it is verified?I have built the uglyface and this make me to built this after hearing the Mick sample.

Or if there is a pcb layout it will much better.

Thanks and have a nice day.

kurtlives · July 26, 2009, 12:24:13 PM

Quote from: Mick Bailey on July 26, 2009, 10:20:26 AM
The LFO switch cuts the power to the LFO to prevent it from modulating the power supply when turned off, so it can't be the LFO making the noise unless the switch wiring has a mistake. Make sure that in the LFO 'off' position there is no power to the LFO IC. The bleed-through in bypass mode may be lead dress. Mine is completely silent when bypassed.

The issue can be fixed I found if I set the thersold lower. Anyways it works and I am happy.

Top Top · July 27, 2009, 01:28:16 PM

The sound samples sound great and I may build this eventually... in the mean time, I am interested in the LFO for another project...

So do I have it correct that this circuit is the complete LFO? Does it rely on anything from the uglyface circuit to work as an LFO?

Mick Bailey · July 27, 2009, 03:04:32 PM

It is a standalone LFO. I originally built an Uglyface, then added the LFO as a separate board.

Top Top · July 27, 2009, 03:39:28 PM

I could use a TL062 or TL072 in place of the 4558, right?

Mick Bailey · July 28, 2009, 12:55:18 PM

Should work fine.

soggybag · July 29, 2009, 01:15:33 PM

As a suggested mod to the LFO mod (can you mod a mod?) Replace the SPDT that connects the two diodes with a pot. This will adjust the shape the ramp rather than just switching ramp up or ramp down.

Top Top · July 29, 2009, 03:48:29 PM

Quote from: soggybag on July 29, 2009, 01:15:33 PM
As a suggested mod to the LFO mod (can you mod a mod?) Replace the SPDT that connects the two diodes with a pot. This will adjust the shape the ramp rather than just switching ramp up or ramp down.

I was wondering about that switch - did I read correctly that it switches between ramp up, ramp down, and triangle waves?

Is it a triangle wave when it is in the off position?

How would you wire the pot?

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Uglyface info required