problem with lfo in uglyface with lfo vero...

[pinkjimiphoton]

hi guys, built this between yesterday and today...definitely works right from the get go, and makes some savagely cool sounds...

but...there's a couple mistakes i found on the layout...where it says out to lug 3 of the volume pot on the board is right, but at the bottom, it says connect lug 3 to ground...it won't work, lug 1 of the volume needs to be grounded.

also, the lfo switch shows nothing connected to lug 3 of the switch....is this right? there's no specific schematic to go with this layout, so it's kinda hard to troubleshoot as a newbe.
i'm assuming the lfo is to sweep the effect somehow, but i'm getting no lfo as far as i can tell. with the switch toward pins 1 + 4, it works, but tpward 3 + 6, nothing!

any ideas?

[digi2t]

You're right about the volume snafu, and no, there is nothing connected to #3 on the LFO switch. You should only hear the sweeping when you play (sensitivity adjustment comes into play), OR, if you crank you the threshold enough for it to run on it's own. Does a wonderful Atari laser gun! I recommend a 250K pot for the frequency, you'll get a bit more low end range on the sweep. Also, 0.001uF caps on both the input and output. This pedal can put out a lot of sizzle high end.

Cheers,
Dino

[pinkjimiphoton]

thanks dino...i did in fact go with the 250 k pot, and it does indeed seem to work better.

but two other things i guess are issues...one, the ramp switch does nothing...is it supposed to be a center-off spdt i'm assuming from some of the threads i found searching?

and...is the lfo switch supposed to kill the whole circuit when it's off? i'm thinking i messed up somehow, it's only supposed to kill the lfo, not the entire effect, right?

gonna debug later, i guess...i followed the layout exactly, but it's not working right.

thanks for the help!!
:thu:

[pinkjimiphoton]

ok, i've gone over this thing again and again, and am stuck...on the lfo switch, when it's in the "off" position, it kills the b+ from the battery dead.
i've tried a couple different chips, no dice.
i seem to have continuity between pins 4 + 5, but don't think there should be any...i've checked the traces, there's no short visible, unless it's either feeding thru other components, or the ic socket is bad.

the rest of the pedal works great...but kick on the lfo, and the battery gets hot if the chips in the socket, so i'm assuming there's a short somewhere...again, could it be the ic socket?

voltage readings to ground on the chip socket with the chip removed are
pin 1 3.34v
pin 2 3.29
oin 3  3.33 v
pin 4 6.82 (batt's getting a little weak)
pin 5 0v
pin 6 0v
pin 7 3.30v
pin 8 0 v

as soon as i put the chip in, the pedal goes dead.

duh....i found the problem....the bottom chip has to be installed UPSIDE DOWN from what you expect...it's hard to see on the layout, or i'm an idiot, or maybe both.

so...if ya build this, make sure you pay attention to the orientation of the lfo chip!!!

thanks again for the help and patience!

[juansolo]

I've built this circuit a couple of times and couldn't get the LFO to perform as per Mick Baileys clips at the top of this thread http://www.diystompboxes.com/smfforum/index.php?topic=66861.20. I chopped it off my boards and re-did my own vero for it that seems to work. For the last one I made I re-jigged the whole combined vero so it fit a little better and corrected the couple of errors I think are in there. It performs how I like it anyhow. re-jigged vero and LFO section on it's own. Though the depth pot on the stand-alone LFO I find better as a trim pot as per the combined.

[pinkjimiphoton]

nice layout juan! 

mine works great once i realized i had the second chip in upside down.

[juansolo]

Nice one, I must have made an error on my original then as I couldn't get the LFO to sweep like Micks does until I grafted on a new one. A well, another vero won't hurt

[digi2t]

If anyone is interested, I managed to hook up an LED to indicated the LFO action. I have it just below my rate knob. The harder you play, the more you dial up the sensitivity, or the faster you set the rate, the brighter or faster it flashes. Sort of an "LFO tell-tale". I can't remember off hand how/where I connected it, but if anyone is interested, I'll crack it open and look. I do remember that I used a clear, super bright red though.

Cheers,
Dino

[pinkjimiphoton]

i'd love to see that, dino....sounds cool!!!

[digi2t]

OK, I took a peek inside. Sorry, no pics right now. I'm in the process of moving, so most of my stuff (including the camera/pc cable) is in boxes right now.

As for the LED, neg leg to ground, and pos leg to lug 2 of the sensitivity pot. That's it. Like I said before, use a super bright clear red LED. I found it worked best, besause there isn't much there to drive it at lower sens settings. It should be just enough to give you a clear indication of what the signal/LFO is doing. Besides, my nephew thought it looked cool.

Cheers,
Dino

[pinkjimiphoton]

cool, thanks dino...when i hit the parts place later, i'll grab one and try it out!