Christine!!!

[Mark Hammer]

I will  heartily endorse the Bandwrecker Deluxe as a bottomless well of fun, albeit less "chaotic".  It is an extensive extension of John Hollis' Crash Sync, that uses a 555 timer as waveshaper.  The mods that Madbean contributed, and I extended, provide LFO-modulated and envelope-controlled duty-cycle of the squared output generated.  Both options sound wonderful, although one can simply reduce the modulation entirely and manually adjust duty cycle for different fixed fuzzed tones.

[Matthew Sanford]

That one does look pretty, I do love vactrols. I did find a 1M feedback on the inside of coupling caps tames her quite a bit, but with waves and vactrols turning the pots, you can get an oscillating (a bit) tremolo and other fun things. I gotta fix some things (bare wire to box I think) on her, plus my Lego foot protectors should come today, but I want to make a good vid to show...

I had thought making the input buffer a dist+ could do a bit too

[Matthew Sanford]

Just to share, I've got her all done! Another vactrol from volume pot to out jack fixed the bypass issue, cut up card to insulate CV switches and leds, and she glitches like a charm!

I went through bypass to show vactrol bypass tone, then straight Christine maxed and various pot settings, then with CV (no invert, gotta fix things) at various speeds and wave forms. Just key of G chords with some single note to show the treatment, and a bit of glitch makes the song.

No lego head foot protection on yet, I have 50 fake Lego people to go through to see who gets to go for the final ride of their life!(and how to paint screams)

[duck_arse]

M. S. = what type pickups on your non-LP - single or hb? one thing I've noticed messing w/ breadboard is just how reactive the frontend is to the selector switch.

[Matthew Sanford]

On the Ibanez stock RG, think hsh, and Samuel whatever their stock is, and hsh or ssh...both 5 way selector.

I was thinking next time I play with Pete I should test the voltage out from his guitar compared to the voltage out from my guitars

[Phend]

Kool build Matthew, great video, watched it to the end. Rated PG. Suspense, sifi, no smoking.

[Matthew Sanford]

Thank you much brother sir. I do like the make a song with the glitch when the LFO is running it in circles.

Update on my guitars, Ibanez is H-S-H (edit: used in video), Samick is H-S-S both bridge to neck like that.

Also, "Let me tell you a little something about love,... It has a voracious appetite. It eats everything. Friendship. Family. It kills me how much it eats. But I'll tell you something else. You feed it right, and it can be a beautiful thing, and that's what we have. You know, when someone believes in you, man, you can do anything, any @#$%ing thing in the entire universe. And when you believe right back in that someone, then watch out world, because nobody can stop you then, nobody! Ever!" you got that right Arnie, man, she believes in me!

[duck_arse]

man, you can do anything, any @#$%ing thing in the entire universe.

man, not me man, I can't get a fecking sound outta this circuit worth keeping it on the breader, yet. man. one more day, I'll trudge back to stock-ish values. then - the scrapyard.

matthew - the input resistor is so way low, it might be worth increasing it some for the recalcitrent pickups. maybe try 4k7 instead of 1k, see if that does anything. each time I switch pickups from H to S, or back, there is a sagging wind-up tone -- or down. if you've heard that sound, you know what I mean.




Basil Fawlty drove a Morris 1500. my sister's first car was a Morris 1100**. so in reference to Christine, I'm allowed to quote Basil when he says:

Our cars have steering wheels.

** it was like the tardis inside, huge.

[Matthew Sanford]

Ah, Basil..I was raised by python and towers, him saying something like "why don't we just serve them chili with a couple of dead dogs on top" and wondering as a child if that would be a meal to serve people.

You might try Taylor's way of not including the buffers, he said it's more responsive to his guitar that way... The way I have mine set up for bypass using back trolls(vactrols...funny voice text), I think it puts tons of Meg feedback resistor from output jack input jack, so I'm not sure if that's changing it a bit.

I feel like I should make a separate box with an input resistor to go before it, and then maybe try it that way with the other guitars

[Matthew Sanford]

Oh the tone! I think due to the oscillator, mine when decaying kind of pitch shifts up or down.

I've found the power starve all the way down (1K left to ground) is a quieter even fuzz but just slightly up the distortion kicks in with good sustain that goes as you turn it higher, getting staccato-ish..also kinda works reverse to gain.

[Matthew Sanford]

Shoot, sorry for a 3 post stream, but Duck if you've got it on the breadboard I had thoughts. First, I'd thought to turn the input buffer into a Distortion +, maybe the gain helps...but in working on the board I had done a meg feedback which did linearize her a bit and bring some sanity. But really the bugging thought is on the difference of different guitars going in, so maybe if the input buffer had a trim to either raise or lower the level of the signal it might be adjustable to each guitar's sweet spot. The thing is 3 inverters in a row, so I'd figure a lower signal on the input would mean a higher one on the out... just whatever you do, be careful what you say to Christine, she is very, very sensitive...

Just thought on my vactrol bypass scheme, in the boxed pedal essentially there are the bypass ones being from input jack to output jack and from effect input to ground, on the effect side there is one from input jack to effect input, one from effect output to out jack, and an indicator led. All CLR to get to about 20mA. Thought then being, when the effect is on there is an input resistor to ground in the 10s of Mohm. I realize you mean the one from input buffer to first inverter, so maybe that would change things? I guess a 10k trim might could be an experiment thing to see the difference, though higher cuts into the gain.

Try a 100k or 1M to feedback from cap to cap on the inside, I know (been a bit, so I believe) it helped to linearize the circuit and make it not loose the sound quite so much, but also ruined some of the charm by kind of compressing it.  It'll be a while before I put it back on the breadboard, but I want to do that later for sure to mess around changing 100ks to 1M, seeing what gain amount changes on the input buffer does, maybe momentaries to push the untied outs of powerstarve/oscillator into somewhere in the signal path, and other things.  Honestly, for my guitars, she is happiest with power starve low but not off, or with all the pots being turned all the time. The LFO (I think) creates this changing thing in the circuit that she is constantly having to adjust to and it keeps the sounds coming out...and puts rhythm to the glitch. Not too hard since gain, oscillator, power starve are all just variable resistance so one vactrol or other choice - on that end, if you do try that, what happens when the out of the osc is used to run the vactrol?

Edit: just notes, so I have been putting a DRM first which is great for my guitars but for friend's LP it was still pretty quiet subdued Christine, however if Christine went off the DRM was full volume. So now I wonder if it is not that the LP puts out too much signal, but then wouldn't really be too little if the DRM isn't fixing it as a booster, so... could the frequency response (removal of bucking high hum) then be the cause? Then again duck you said you used singles and it was same issue, no high frequency removal there...hey as a crazy maybe an inductor wrapped on that first 1k....

Last Edit: reading on other 4049 linear posts, one thing people do is different resistors from VCC to pin 1. I think on mine I just used a 47R not the 1k recommended, cause after burning a 1/4w 47R touching other things on a druid breadboard thing I bought a pack of 1W, so they go everywhere. Still, I wonder if limited the power differently might then affect what inputs make it the whole way through? Sheesh, I hope this is my last edit....

Maybe last edit?!: uh, last thought. Might try not doing Vb for the buffers. I know it worked without that before for me, though works just great with Vb, but maybe for H pu it would be happier hitting the ground rail... So Duck! Many things to try before ditching it from the board, maybe try this with original values but the mad crazy idea of no biasing op amps...

Ok, last edit: datasheet says max input 0.1uA (1A @ 85C) so across 1K input max 0.1volt...does the 100k Rf affect it? So maybe you're right, 4k7 for 0.47v...

[amptramp]

We did some experiments a while ago using 4049's as amplifiers and running them in liquid nitrogen for reduced noise.  Other than the occasional cracking noise, it continued to operate at 77 Kelvin, a quarter of room absolute temperature, so we were getting half the noise.  What we found was that each section of the hex inverter would draw 8 mA at room temperature when the output was going through Vcc/2, the midpoint voltage.  If all six sections go through the midpoint at the same time, you have an instantaneous current drain of 48 mA going into the chip.

If you have a 47 ohm resistor going into the Vcc terminal, this creates an instantaneous dissipation of 2.256 watts.  No wonder they get hot.

We used to make infrared sensors using InSb, PbSnTe and other materials in photovoltaic and photoresistive form respectively and they were individual diodes because no one makes these in IC form.  This is a lot of sensor outputs and they need a separate amplifier for each of them.  This is why we were looking into hex CMOS gates as amplifiers.  They all proved to be too noisy, but it was worth a look.

[Matthew Sanford]

I read an old thread or two about a pot from VCC to add more distortion with more resistance. I think it's interesting how they change as they get hot, say input current max 0.1A 25C and below, then 1A at 85C and above, and I had felt she ran better once warmed up. Interesting about lower noise in lower temperatures

[duck_arse]

close observation of the circuit diagram shows there is no supply bypass. there is V+ cap to ground, but there's nothing across Vcc and Vss. and as Vss is raised above ground, when the oscillator starts its racket, it modulates the unbypassed supply, which then havocs the whole chip, at high gain.

so you add some bypass caps, and that changes the whines and the releases and such. but there's three ways to add bypassing - you can add it across the fixed R in the sag. you can add it across the sag pot, which will then vary the bypassing effect as the sag changes, OR you can bypass across Vcc and Vss. all have differeing effects, and all vary with cap value. some values aren't useful. start at 100nF and go up to 22uF.

of course, if you have the thousand vactrol version, none of this will apply. there will be so much hufing and shuffing from the lfo's tha the bypass caps won't ever keep up.

another way to get some control and release of the oscillator section is to add a cap between the input gain section and the 1k to the oscillator. I'm testing with 1uF POLY. MUST be poly! changing the resistor to 5k6 is also in test, for more gentle response.

also, and no edits, the sag pot to A20k, and the oscillator pot to A100k. don't bother messing with the original values.

[Matthew Sanford]

On the power starve (sag) there's a 10u to ground, isn't that bypass on supply (that's the bypass you were talking about, right?)? I wish I took (better) pictures but I feel I must've used the 1k Vcc to Pin 1, and then with the ground only 1k above ground it has more that smooth tube sound to it, but once that increases just enough is when the nasty distortion kicks in, then more makes it chop the sustain. Hadn't thought that it was a minimum of 1k from either rail...and is it the unbalanced resistance to Vss/Vcc that then causes it to clip so? I haven't played with mosfet clipping, so no info in me head there.

I'm going to have my friend bring his LP over this weekend so I can see what the output voltage is compared to what I have. I was figuring the input current would be an issue, then very interesting that when up to 85C (whoa, that's 185F?!) that it is fine with a full decade higher, but old cars do need to warm up. So maybe I'll leave it plugged in an hour before he comes to see if she'll behave for him.

I have to say I do like the original high values, was almost going to make them bigger, bigger resistor is bigger noise, no? And she should be noisy.

Anyway you are right, I love the thousand vactrol dressing (do not like thousand island dressing though). When they are all going it is just trying to catch up constantly, but puts the glitches into that rhythm. However, without them she can be great about it, very choked with power starve (sag) at max and just smooth tube (ew) with it low. Well... for the guitars I use. I ... shoot, I was thinking to put more resistance before the pedal input (to try my friend's LP) but that's pre-buffer so probably not exactly the same as increasing the 1k after, though possibly still reducing the voltage to then reduce the current after. Hmm.. I'll try a pot to split the voltage down and see how that goes too.

[Matthew Sanford]

Found a early pic, 47R from VCC to pin 1 on my build...might've added a 10u Vcc bypass cap there too

[duck_arse]

see this again. +9V and ground are bypassed with that 10uF, so AC grounds. see how pin 8 has the power starve rubbish between ground and Vss. so all that resistance is unbypassed. and the chip, from Vcc to Vss is also unbypassed. any current that flows through the starve causes a voltage drop across the starve, and there is no cap there, anywhere, to catch and hold those wobbles. so all the invertors cop the wobbling, whether they want it or not.

same will apply if you have shifted Vc from Vcc by inserting a resistor, 47R or not, between supply and pin 1. you would then have an un-bypassed point, Vcc, which will wobble with current.

how much capacitance, and where you put it, will affect differently. trust me, I've heard it.

now here, look, I know you are also worried about those two unused invertors, I know I am.



make an oscillator, you probably need one. it will square wave, it probably won't drive a led directly, so use a pnp [connect sq_OUT to sq_IN] and there will be no silly confusions about supply and ground. the led can do anything you want, brightness via R4 value -- or you can use the transistor to shunt, say, another resistor, maybe in the starve line. no ldr!

be warned - I have this working on the breader in total isolation. I haven't tried varying the supply, or starving the supply, but I'm fairly sure the set frequency will jump about with all the supply funnies all your leds will be inducing. so, mayhem, probably. but no leftover IC.

[Matthew Sanford]

Funny, you'd got my brain thinking and now I come back feeling bad to bring it to the top but to throw more madness on the fire! I hadn't noticed the power cap on TTG's scheme but it's there, and 1k to Vcc. Here, Taylor took that 1k out and put the diode protection with the cap, plus he didn't like the buffers, said more responsive to guitar tone/volume knobs without them...but I wonder if the lack of the Vcc resistor also influenced that? I know, even buffered, 47R Vcc resistor, etc, it will go cleaner with the volume knob down.

What got me back (in the nick of time!) was the power starve, the Vcc resistor, the fact that resistance to either ground or Vcc seem to create more distortion, then thinking what if you took the two power starve inverters set them like the power starve as singles to both pin 1 and pin 8, maybe a dual 100k pot. I would think that current limiting in both ways would kind of make distortion out of it more symmetrical, but not really sure on it. For sensibility's sake I've put an order to the things waiting for me to work them, but I think when the breadboard comes back out I may just put her on it again. I love the boxed one I have, but would like her to work with whatever goes in, or not I guess if she gets really silly. Plus, I want to see what getting gain/distortion from the input buffer would do, would that keep the signal strong enough to not glitch so much or is that more on the messing with power rails part? So many questions...

Interesting mods you make, I assume those two are the old power starve ones for the square...might be interesting to just throw that square into the oscillator section. I can't help but love putting the (L)DR. LEDs on the pots, but I've been thinking what it might sound like with the LFO level lower, for more a wobble instead of extreme resistance changes - I'll try it. Then thinking on the tap tempo thing to replace a schmitt might be better to replace the triangle back to the schmitt, and I think with how I'm putting triangles in (like that other thing) it would make the rate pot on the triangle then turn in to the depth with it wobbling offset to the Vb on it...hmmm... another post, that.

[duck_arse]

can now report. that oscillator I showed, very nice osc it is, works a treat, values scale nicely - only, it's not for this pedal. when it runs, that's all you get. so it's just as bad as the original oscillations knob, when unfettered.

short answer - park those two unused invertors on Vss. long answer - I'm tempted to convert to a 4011, only four gates. but then they can be gated, externally. but then, they need more circuits to do the gating. but, the "more circuits" could have a proper supply section to theirselves, bypassed and all.

grrr.

[Matthew Sanford]

It bothers me that she doesn't cooperate with only (well, seemingly) certain guitars. I'm thinking back, and she would cut or not before but has been well behaved for me - also, I got her to go the Taylor way (no buffers), no Vb on the input/output buffers, and with the Vb - but not always consistently.

Try the less gates way, it seems really the distortion comes from the resistance to ground from chip ground (and to Vcc as well), but really do those two need to get tied in to that? well... not really... I wonder with them straight to VSS while chip ground pin goes through resistance, what would that do? I guess you already worked those way...