Uglyface info required

Mick Bailey · April 24, 2008, 04:53:13 PM

Here are a few sound clips. Not happy with the sound or uninspired playing - cheap Manhattan Strat copy, neck pickup, tone rolled off, no reverb, no overdubs, no nothing. Straight into soundcard.

I've made a further improvement of putting a .01uf cap across the input of the main Uglyface board. I liked the improvement in tracking better than with the .001uf I;ve seen used elsewhere.

http://www.avwz35.dsl.pipex.com/medium sweep.mp3

http://www.avwz35.dsl.pipex.com/medium sweep2.mp3

Last one is with the threshold turned right up to give a background beat
http://www.avwz35.dsl.pipex.com/pulse.mp3

andrew_k · April 24, 2008, 08:33:09 PM

Oh wow. wow. wow.

Did I say WOW?! I love this Mick, excellent work

I'm working on a complete perf layout now of uglyface + your mods, but perhaps you already have a vero or perf layout that you used?

Thanks for sharing this crazy mod.

andrew_k · 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.

andrew_k · April 25, 2008, 08:01:24 AM

Mick: what are the specs of the LDR/LED pair you used? I've got a 3mm red LED with an LDR that measures ~1M in dark. You think that will suffice?

Mick Bailey · April 25, 2008, 08:44:59 AM

I tried 3mm LEDs and they work fine, also a 5mm 'water clear' type. The LDR i use for all my opto couplers is;

http://www.rapidonline.com/Electronic-Components/Optoelectronics/Photodetectors/Miniature-light-dependent-resistor/34796/kw/58-0134#techspec

The key to success with any opto-coupler is to ensure it operates in darkness. My own shows about 1M in the 'dark', but when light is totally excluded the resistance is higher. It sounds like you have the right one. There is some flexibility in the design and you can always experiment with the series resistance on the output of the LFO - this is why I included it originally. If you use the heatshrink tube to couple the resistor to the LED (recommended) you need to ensure that no light creeps in through the open end on the LED side. Light leakage can pass throught the LED and affect the dark resistance. If you can't get an easy octave down, check this first, especially at the breadboard stage (I used some black card at first then found a tin of blackboard paint and put a couple of drops in on the back of the LED).

The 220k frequency pot can be added at any time, along with the equalising resistor soldered across the lugs. What this does is to give a more reliable octave down which tracks more readily and gives a lot more bass.

I etched a pcb originally after breadboarding the LFO and mounted my diodes on the back of the switch. I don't mind publishing this - I'll tidy it up.

The French connection · April 25, 2008, 09:06:49 AM

What is IC3? Any 4558? Nice soundclips BTW!

Good job.

andrew_k · April 25, 2008, 09:24:57 AM

Oh snap, I didn't mark IC3 on my layout. It's a dual op-amp, 4558 should be fine.

Mick: Thanks for the details, I was going to wait to do a larger order but if the local store has the parts I'm missing I think I'll have to have a stab at the perf layout over the weekend.

Austin73 · April 25, 2008, 10:20:12 AM

That does sound pretty cool indeed Mick, but don't suppose anybody has a vero layout for the whole shibang? lol

Cheers

Aus

big bustle · April 25, 2008, 01:44:31 PM

i updated my previous layout to fix the issue of ground not being connected to a few components.

mick, i don't have a 220k pot. you think 250k will work just as well?

Mick Bailey · April 25, 2008, 02:20:42 PM

250k will be fine - in Europe we get pretty bizarre values of 'standardised' components - 4.7k insted of 5k, 470k instead of 500k. Because of tolerances it doesn't really matter, so use the nearest value. The equalisation resistor stays the same.

I suppose any dual op-amp would work fine. I happened to have a dual 741, so I used that. The 4558 is expensive here, so I only use these for signal processing. In the LFO it just has to turn a light on and off!

I don't have a Vero layout - my original Uglyface used a PCB and I added a small PCB later for the LFO.

BTW, if you're using an Uglyface with a JRC chip, try switching to an LM386 (I got mine from Maplins, or is that Craplins nowadays?) and alter the 2.2uf cap to the wiper of the sensitivity pot to 100uf. You will not believe the difference.

Mick Bailey · April 25, 2008, 03:42:53 PM

Please note;

I discovered a typo on my original schematic - C1 should be .01uf NOT .001uf. Now amended. Sorry for the confusion.

big bustle · April 25, 2008, 03:51:26 PM

Quote from: Mick Bailey on April 25, 2008, 03:42:53 PM
Please note;

I discovered a typo on my original schematic - C1 should be .01uf NOT .001uf. Now amended. Sorry for the confusion.

i updated my layout on the first page to reflect this

Mick Bailey · April 25, 2008, 03:57:03 PM

Here's my original DIY Layout Creator design that I etched an I know works. No off-board components are shown and the ramp diodes were mounted on the switch (not a particularly good idea, but the switch is right next to the LFO speed pot in my own build). It was a hasty job late one night done in excitement after breadboarding. The connection pads are large because I use Vero pins and like a generous pad.

GIf image
http://www.avwz35.dsl.pipex.com/lfo.gif

DIY layout file
http://www.avwz35.dsl.pipex.com/lfo.diy

big bustle · April 25, 2008, 04:13:12 PM

i noticed that r2 and ic pin8 have +9v and the +9v it switched on the schem. would there be any reason to have it wired up at all times?

Mick Bailey · April 25, 2008, 04:24:16 PM

You can either switch pin 8 only, as per the schematic, or both pin 8 and the +9v to the 470k resistor (I noticed I've reversed the names of R1 & R2 in the PCB layout) Either will work. I built my own with both 9v feeds switched.

Well spotted - I'll amend the schematic to avoid confusion.

I'm also having problems getting LFO.DIY to load - it FTPs up fine and loads, but gives a 404 error when viewed off the web.

Mick Bailey · April 25, 2008, 04:53:14 PM

Schematic and GIF amended.

Just realised why the .DIY file won't load......Someone tell me I'm a dummy!

big bustle · April 25, 2008, 05:03:56 PM

Quote from: Mick Bailey on April 25, 2008, 04:53:14 PM
Just realised why the .DIY file won't load......Someone tell me I'm a dummy!

i will do no such thing! if this works for me i will proclaim you as a diy hero! i will need a recent photo for the tattoo of you on my left bicep, next to gene wilder.

andrew_k · April 25, 2008, 06:51:31 PM

Quote from: Mick Bailey on April 25, 2008, 03:42:53 PM
Please note;

I discovered a typo on my original schematic - C1 should be .01uf NOT .001uf. Now amended. Sorry for the confusion.

Thanks, fixed on my layout.

jstack · May 03, 2008, 01:14:58 AM

Thanks a lot for that perf layout.
I noticed that the vactrol isn't labeled though...
Which one does this circuit use again, is it the VTL5C9?

Also is the layout confirmed?

andrew_k · May 03, 2008, 01:32:47 AM

jstack: the layout is not yet confirmed as I have a stack of half-finished projects that I'm forcing myself to complete before I start more

I have checked it over multiple times and the UglyFace portion of the layout is directly copied from a verified layout. It's only the LFO+switching part of the circuit that I have added.

The vactrol is not marked because it isn't marked on the original schematic. Mick reported combining a photocell with a dark resistance over 1M with a clear (red) 5mm LED was successful for him. I have the same parts and will be using that as it's easier to get and cheaper than a vactrol. the DIY vactrol is pretty easy to build, except you have to ensure it's light-sealed.

Please report back if you build the layout and I will mark it as verified

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Uglyface info required