Escobedo PWM with Mods -Verified

[frederickpdog]

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[Synsound]

Could you explain the pot values. The layout refers to Fine and Corse while the notes list Rate and LFO.

[frederickpdog]

my bad posted the non updated one lol... one minute I'll post the right one

[frederickpdog]

-Verified  

I made this one the other day and added the octave downs for more fun, neat little circuit...

On the demo video I made the octave blend a trimmer inside it was a mod at that point, its worth having external.

https://www.youtube.com/watch?v=7ID78AVC_8w

 -Ryan

[edo1123]

Is the lm40106 equivalent to the cd40106?

[frederickpdog]

Yeah the tayda ones work fine...

http://www.taydaelectronics.com/cd40106-cd40106be-40106-hex-schmitt-trigger-ic.html

I have a handful of the SGS/Thompson ones they are labeled a little different, sometimes they are HEF40106 too, so whatever you can get the deal on. I always recommend getting a few you'll run into other circuits that are cool that will take them.

[boratto]

How about to include an additional led led for the rate? Where to put the 2k2 resistor (that goes to the rate anode leg)?

[edo1123]

I've just finished it and, as usual, it doesn't work. I'm pretty sure it's not the board (I've spent half a day to complete it). The only thing I noticed is the 1M resistor connected to the 4th pin of lm386. It should be connected to the ground, but it is not.. I checked the voltage and pin 4 gets about 0,89 volt.. Should it be? Maybe I'm wrong, but I'd like to know if it is possible.

[edo1123]

I was right.. I've replaced the 1M resistor with a jumper connected to ground. Now it works. The lfo knob works for just 1/3 of the run, but it sounds great..

[frederickpdog]

[frederickpdog]

Had a little update to this. Added a simple tone stack made it fun to shape the wackiness of it. Also I think on the other layout I missed a link between pins 2&4 of the LM386 sorry took so long to get back to you guys been busy. -Ryan

[frederickpdog]

here's a little demo of it...
https://www.youtube.com/watch?v=9k1qy2g29rE



here's one I modded a little more...
https://www.youtube.com/watch?v=L2jZAzKQtxI

[gul]

Any updates/tweaks to the layout before I get started building? Just saw the demo video for this and it is a must-have. Thanks for the layout, Ryan.

[BetterOffShred]

Yeah I'm curious about this too.  The 100n cap right in the middle that's horizontal .. it doesn't straddle a cut or something?  It's kind of sitting there on an uninterrupted row?   Cool effect though.
-Brett

[BetterOffShred]

Is there a cut missing on row 11 where that 100n cap is? Or is the cap supposed to be down one row?  I'm digging this effect but that component is bugging me! Thanks for posting it, it looks pretty fun.
-Brett

[gul]

I built the second layout (w/ tone stack) a while back and it didn't work properly. The rate and LFO knobs seem to be working. I hear a drone-y synth noise that changes in time (Rate pot) and in intensity (LFO pot) as I turn them, but no guitar signal is getting through at all. I spent an hour going over my build vs. the layout, the only things I found out of place or funky were a couple of messy trace cuts. I went ahead and re-knifed the tracks, as well as all of the trace cuts... Still the same drone-y synth noise that changes in time (Rate pot) and in intensity (LFO pot) as I turn them.

I just spent another hour or so probing it, and I keep losing the guitar signal after pin 3 of LM386.  I re-flowed the solder, re-knifed, put in fresh chips. I tried two different brands of LM386 chips, as well as versions LM386-3 & LM386-4, just for fun. As an aside, I noticed the drone-y synth noise sounded a little bit different with each version of the chip.

This is such a cool circuit, I want to figure this out! I might have to mess with that 100nf cap. I'll put it to rest for today but I'm definitely going to re-visit it again one day.

[BetterOffShred]

Ever try that cut under the 100n Loe?

[gul]

I did. Still no luck! I still have the circuit, but I haven't had time to mess with it anymore. I wish I knew what schematic was used. That always helps immensely with troubleshooting. Please post if you get it going! I would love to save it from the fail bin.