uglyface - WORKS! but no space gun sounds - what's wrong?

[big bustle]

i but my ugly face on breadboard

i went stock with everything.

it has a vactrol and chips i got from small bear. it does the octave stuff. self oscillates. it's wonder full. but what i really want is the space gun sounds!

i found the post with the directions for knob settings and tried that.

link here:

http://www.diystompboxes.com/smfforum/index.php?topic=42730.0

here's what happens:

i set the threshold all the way into extreme oscillation mode. freq to the lowest setting. and then i tooled with the sensitivity  in every direction. with it up all the way i get slight plunging. but i don't get the hi-to-low sweep. i played notes all over the neck. higher notes don't plunge/ there's crackly blenmd that happens. i did muted notes and sustsained note.

i have no idea what's going on.

my guess is maybe the oscillator isn't tracking the high notes on my guitar. im using a USA tele built in 2001. neck pick up tone scooped all the way. it's the best gtr i have for any octave circuit tracking.


thanks in advance folks.

[big bustle]

ok... so i did what seems like my 12th search on the boards on this one....


i found this post where someone else has the same problem

http://www.diystompboxes.com/smfforum/index.php?topic=46253.0

i then took the home-wrecker mods to heart and added .001 caps on the input and output.


this still hasn't changed my problem.

i think i understand why

the issue occurs with in the opamp/timer chip interaction. these output pots will have no effect on that since they are so far past the signal processing. considering their placement they are flowing electrons to ground.

from the input to ground and output to ground.

we know that caps to ground kill hi-frequencies because that's what's on gtr tone knobs. but conversely resistors to ground cut lows.

correct?

is there a chart some where that shows the resistor and capacitor values that correspond to frequency filtering?

[Processaurus]

Hey, I got mine to do this with a spdt toggle switch by disconnecting the audio input to the 555's reset pin, and and instead tying the reset pin high, to make it oscillate by itself.  The audio is still connected to the LED/LDR, so it sweeps the freq down.  There's the ray gun soundz.

Its neat how it works by using the audio to reset the timer, on a scope you can see the 555 pulse a bunch of times during the positive half of the input signals cycle, and then it stops during the negative half.

[oldrocker]

There's a sample of the space gun sounds on my Uglyface on my sound samples website.
http://randallbarnett.homestead.com/SoundSamples.html

[JonFrum]

When the day comes, and aliens actually invade us, I'll be totally disappointed if their guns don't sound right.   

The Uglyface is on my to-do list, so I'm following this thread closely. 

[big bustle]

There's a sample of the space gun sounds on my Uglyface on my sound samples website.
http://randallbarnett.homestead.com/SoundSamples.html

damn you, old rocker! why must you mock me! 

does anyone else want to rub my face in my non-space-gun soundage 

Hey, I got mine to do this with a spdt toggle switch by disconnecting the audio input to the 555's reset pin, and and instead tying the reset pin high, to make it oscillate by itself.  The audio is still connected to the LED/LDR, so it sweeps the freq down.  There's the ray gun soundz.

Its neat how it works by using the audio to reset the timer, on a scope you can see the 555 pulse a bunch of times during the positive half of the input signals cycle, and then it stops during the negative half.

what does it mean to ty the reset pin to high? can you elaborate a bit more.

[oldrocker]

Oh sorry.  Double check the 10k threashold pot wiring.  When turned all the way down and you play muted strings it should start firing.  Don't let the strings ring out or it won't work.  You just want to click the pick on the strings or pluck them while muting them.

[slacker]

Does the envelope follower do anything? For example if you've got it set so it's not oscillating and you turn sensitivity pot up you should get a sort of wah/filter sweep type sound as you play.
If nothing happens it sounds like your vactrol might not be wired up correctly or there's a problem between the 386 and the sensitivity pot. If you set your DMM to AC and probe at the top of the sensitivity pot you should get about 2 volts on hard guitar strums. The other way to test if you're getting voltage to the pot is to disconnect the vactrol and replace the LED side with a normal LED, it should flash as you play.
If it doesn't it means there's a problem between the 386 and the pot. If it does then it probably means you've wired the vactrol up wrong or  there's something miswired so the changes in the vactrol's resistance isn't having an effect on the 555s frequency.

[big bustle]

the envelope follower does do stuff. it's a very slight envelope sweep.

i have connected an LED and the led did light up as i played.

you mentioned

If you set your DMM to AC and probe at the top of the sensitivity pot you should get about 2 volts on hard guitar strums.

when you say top of the sensitivity pot you mean the casing? or a specific pin?

[slacker]

Sorry when I said the top of the pot I meant looking at the schematic the pin that's at the top. The one that's connected to the 2.2uF capacitor.

[Processaurus]

Hey, I got mine to do this with a spdt toggle switch by disconnecting the audio input to the 555's reset pin, and and instead tying the reset pin high, to make it oscillate by itself.  The audio is still connected to the LED/LDR, so it sweeps the freq down.  There's the ray gun soundz.

Its neat how it works by using the audio to reset the timer, on a scope you can see the 555 pulse a bunch of times during the positive half of the input signals cycle, and then it stops during the negative half.

what does it mean to ty the reset pin to high? can you elaborate a bit more.

Hi, sure, tieing something high or low with logic chips means connecting an input to either GND (low) or the positive supply voltage (high, +9v in this case). 

[Processaurus]

Had an inkling of an idea how to do the mod I did, but to get the thing to shut up when you're not playing, forget about tying the reset pin high, instead you could hook up another LED to the top of the 1K sensitivity pot and ground, and have that shine on an LDR which is hooked from +9v to a 1m trimpot set up as a variable resistor to ground, so that it makes a voltage divider.  Hook the reset pin to the LDR & 1M trimmer junction, and adjust the trimpot in a way that the voltage the reset pin sees is high enough to enable the oscillation when you play, and low enough that its off when you're not playing.

So if you wanted the gated raygun sound on a switch, you'd hook pin 4 of the 555 (the reset pin) to common on a spdt, one throw to the existing UF circuit, and the other throw to the LDR/trimpot voltage divider.  Maybe a momentary stompswitch for momentary raygun sounds?

That would mean you could just make it oscillate one synthy note and not sweep if you wanted, but it would be gated by the guitar input.

Now that I think about it you probably could reverse the sweep of the frequency with this idea puretube shared.  Though you'd need a 3pdt toggle switch or different LED/LDR combos.