re: gristleizer

[pinkjimiphoton]

hey guys, just spent a couple hours plugging every bloody opamp in the house into one of these suckers,
and found one particular dual opamp that seemed to rEALLy shine over all the others.
i was having a bit of a ticking problem, and the bias and depth knobs were really touchy.
i tried the usual tl082/72/62 ne5534, op275, and none of 'em were ringing the bell all that well to my ear.
so i tried an lm358n, and viola as dino would say
bing-0-freekin'-rama!
the thing literally came to life, and i played with it for the last 4 hours or so which is just beyond ridiculous.
there's a range in the bias and depth knobs now too where it will self oscillate in the most amusing kinda hip-hopish way thats both predictable and random.
getting everything from phase shifting to harmonized distortions out of it.
if ya socketed it in your build, and ya have one of these chips laying around, check it out.
i looked up the data sheet after the fact
http://www.ti.com/lit/ds/symlink/lm158-n.pdf
and it looks like for this circuit its actually a really good way to fly due to its properties.
anyways, if i ever get some time where i can do it, i'll try and do a crummy video.
i can't believe the saxomophone and trumpet kinda sounds. guitar synths that come in as you work down the neck. in-bloody-farkin-sane.

anyways... all for now, happy camping and gristle on!

<time to add an exp pedal input on this puppy for the bias >

[diffeq]

Hi, Jimi 

LM358 is a single-supply op-amp and it's output can swing as low as -V supply. Maybe it gives the LFO an extra punch? It also has somewhat low bandwidth, which can be giving it same effect as LM308 in a ProCo Rat. I might throw some russian very-low-bandwidth (0.7MHz!) opamp in it to see how it sounds. Anyway, thanks for the tip.

[Kipper4]

A TL022 might be ok too for the oscillator Jimi.
|It's low current IIRC which will help.

[pinkjimiphoton]

thanks guys,

is this what you folks refer to as "rail to rail"?

it for sure seems to make a huge diff.. less ticking, better sweep and even some formant-y sounds.

i think its one of them deals like, "when in doubt, try a 5088"... which will work, but sometimes, older, less useful chips seem to sound better.

i built a cornish g2 style distortion the other day, same deal. i used the reccomended parts, and didn't like it. the clear tonal winner was a combo of an lm301 and a 741, both the old school metal can ones. in the end, i went with an ne5534 for the first oa, and a 301 for the second. it just had the best balance, crunch, tone, and lower noise than the modern opamps had. they all seemed to sound like, "an octave" too high... too much hiss and noise.

i postulate that to recreate some of these old effects, ya really do end up needing some buggier devices sometimes. i'll bow out with GERMANIUM!!!

or toobz!

[diffeq]

thanks guys,

is this what you folks refer to as "rail to rail"?

it for sure seems to make a huge diff.. less ticking, better sweep and even some formant-y sounds.

i think its one of them deals like, "when in doubt, try a 5088"... which will work, but sometimes, older, less useful chips seem to sound better.

Well, almost. LM358 can only do half of what rail-to-rail is capable of - just lowest output swing, while rail-to-rail can also swing to full
highest supply / +V (+9 volts in our case). One of them would be TLC2272, CMOS op-amp (might not sound as good though, but personally never tried it)
Speaking of tubes, this guy made a fully tube-based synthesizer:
https://www.youtube.com/watch?v=lU1yJN7Lfn8

[Kevin Mitchell]

Speaking of tubes, this guy made a fully tube-based synthesizer:
https://www.youtube.com/watch?v=lU1yJN7Lfn8

[pinkjimiphoton]

the chip sounded great in the thing, but with one of my bigger amps, was pretty unstable.
so i stacked it with an ne5532. holy sheet. i think thats the magic combo so far.
finding there's things about this circuit i love, and some i think need to be addressed. i'm thinking buffered blend for the dry signal, fine tune pots for the speed in particular. it does seem to hang up sometimes and really slow modulations are hard to dial in.
but man.., what a blast

[Marcos - Munky]

Speaking of tubes, this guy made a fully tube-based synthesizer:
https://www.youtube.com/watch?v=lU1yJN7Lfn8

As cool and nice sounding this synth is, I can't stop thinking how high is the bill after a month playing it every day

[Ben N]

Speaking of tubes, this guy made a fully tube-based synthesizer:
https://www.youtube.com/watch?v=lU1yJN7Lfn8

That just broke the Geek-cred-o-meter.

[Marcos - Munky]

After reading your topic, I've listened again to this soundclip (https://www.youtube.com/watch?v=KZmZQ2B2K70) and the Gristleizer got me interested again. Question: which layout did you used? I have Gaussmarkov one, but it uses single opamps, and you mentioned yours uses dual ones.

[pinkjimiphoton]

hi munky,
i bought this on evilbay
https://www.ebay.com/itm/Guitar-Bass-Accessories-Gristle-Tremolo-Auto-wah-Synth-Effect-Pedal-PCB-Only/183100128432?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

it was marketed by a cat that goes by 3pdt. there is no schematic, just a build doc that comes with it.
its a decent board, kinda pricey tho i thought but i was lazy and had disposable income at the time.

it reccomends an icl7660 charge pump, but it audibly whines. a 1044 seems to work better, in this one, anyway.

in the end i went with a tl074 and a stack of lm358 and ne5532 for the oscillator part.  to me, the combo seemed to work better than any dual opamp i had there. all 4 positions for the waveforms now seem to work right without having to mess with the bias too much.

i also tried a bunch of different transistors in it, and found other than pnp/npn gender, they made literally no difference tonally. i even tried... of course... germanium. would be a waste.

so i went with a j112 for the jfet <had to twist the legs around> a 3906 and an mpsa06.

hope to get some video soon. life's been happening!!!!!!

hope all is good man... peace!

[Marcos - Munky]

Thanks for the info, Jimi. I thought it was an available to etch layout, the only one I found is Gaussmarkov's one. Also, thanks for the info on the parts you used.

All is good here, hope all is good on your side. Peace.

[pinkjimiphoton]

i think fuzzdog's build doc has a pcb layout in it munky
there's also one in the original GEU or whatever it was project, before it became the gristleizer

[Marcos - Munky]

Fuzzdog's build doc doesn't have the layout, and it's probably dual layer by the size of the board. I'll go with Gaussmarkov's layout when I build it, there's a few projects on my to do list I need to finish before I start this one.

[pinkjimiphoton]

so sorry, man!
i thought i saw it there when i was researching the circuit... my bad!

[Marcos - Munky]

Nah, don't worry about that. GM's layout is pretty good, it just have lots of offboard wiring. I need to finish some stuff first, this one will probably be made by the end of the year

[pinkjimiphoton]

i feel ya, bro!!! lmao!! happy soldering!