EnvoTrem a work in progress

[duck_arse]

sounds good, except for the fright at the end. have you tried jon's single pot atk/dcy method?

[Kipper4]

Not yet tried jons  method. Still got much work to do.

[Kipper4]

I tried a few ways of implimenting this


"Oh ... for good measure, if R7 and the decay pot are a voltage divider, you get a single control that affects the attack and decay at once AND give you a threshold control of sorts. You will have to change C3 to something bigger and use a smaller value pot, though. It would also let you shunt the envelope to ground, giving you a way to kill the envelope control completely, which you don't currently have."

I think i've misunderstood it or left it too late into the early hours to get it.
anybody care to explain it please to this thicko.....
thanks

[duck_arse]

I haven't tried it either, but if I did, with ref your V10, I'd toss out the 1k attack pot, and the 50k decay pot, and make R8 and R26 a single resistor. now pot a 50k pot with CW to the diode and CCW to the new R26 (10k?) to ground. then wire your C3 to the wiper and ground, and take the envelope out from the wiper.

now, when you wind the pot CCW, you've got 0R attk, and 50k dcy. wind it Cw, and the attk increases while the dcy decreases.

[Kipper4]

A little more progress. It's starting to behave better.
I ditched the tremolo vactrol and went for a resistor (ldr) to ground configuration, changed lots of values, did the threshold mod with a fine control.
Still got lots of trials to do. Thanks for all the help guys.

[Kipper4]

Another update video


https://youtu.be/tq8v3II2I3k

[duck_arse]

there's a very definate step, from no sweep to sweep, isn't there? is that a good thing or a bad thing?

some cleanups - R11 and R17 are in series, so you only need one, total. same goes for R13 and R31. also also R8 and the 12k to its left. (unless you're series values-ing to make-up inbetweens you don't have, in which case, ignore me.)
C2 can be reduced - to maybe 47nF. same for C1.
for switch 2B - ditch R7 and R24. split R18 into two 4k7's, switch between the top of the bottom and the top of the middle (so gnd-4k7-switch-4k7-switch-6k8-supply -- check your voltages are right enough).

at lowest osc speed, and widest sweep-to-fast, does your osc stop/tend to die/lose depth?

[Kipper4]

there's a very definate step, from no sweep to sweep, isn't there? is that a good thing or a bad thing?
I guess that depends on the use of the effect. I added a fine tune pot to the threshold mod so it will sweep smooth or if you like that sort of thing and want to make use of some of the envelope ripple it will do a sort of morse code thing.
I swapped out some more values and the lfo doesnt stall so much
"at lowest osc speed, and widest sweep-to-fast, does your osc stop/tend to die/lose depth?"

Although when it did stall more it brings a clarity to single note and even chords that makes them stand out more.
It's a bit of a pedal that you wouldnt use all the time anyway. Just for a special effect.
I really need to stick a fuzz up front of it too. just cause Jimi Photon would.

Thanks for the fet lesson D.A.
Now i have even more things to try besides the op amp lfo which i havent even looked at yet.
Hours/days/weeks of fun ahead.

You got the enveloped vibe done yet??? I'll think of some twists for ya.......

[duck_arse]

if by "done" you mean a third version diagram and a list of problems, then yes, it's done. looking for some players to breadboard it for me, might call it the wrinker vibe.

and you know the opamp version lfo has a voltage controlled variant, don't you?

[stringsthings]

The EnvoTrem sounds very interesting.  Are you ( or anyone else ) planning on making
a PCB layout in the future?

[Kipper4]

 "looking for some players to breadboard it for me, might call it the wrinker vibe."
I'm in. I probably have most of it still on my smaller breadboard anyways.

"and you know the opamp version lfo has a voltage controlled variant, don't you?"
Nope. expand on this please.....


@Stringsthings
"Are you ( or anyone else ) planning on making a PCB layout in the future?"
I'll do a perfboard layout in DIYLC. Which could be adapted easily.

[Kipper4]

One and a half bloody hours tonight trying to make a bjt variable resistor on the breadboard.
It turns out it wouldn't work because my connection was off by one hole..... Doh
I was cursing Stephen.
Well its working now. No more vactrols. New schematic in the morning.
Its still a work in progress guys So am I.

I'll just leave this here for a later reference

http://www.muzique.com/schem/doctor-q.gif

[duck_arse]

for example, the LM358 datasheet, on page 10:

http://pdf.datasheetcatalog.com/datasheet/nationalsemiconductor/DS007787.PDF

this same VCO circuit appears in nearly every dual/quad workhorse opamp datasheet.

[edit :] curse all you like, cobber! good news, I've crossed one problem off that list.

[bloxstompboxes]

"looking for some players to breadboard it for me, might call it the wrinker vibe."
I'm in. I probably have most of it still on my smaller breadboard anyways.

"and you know the opamp version lfo has a voltage controlled variant, don't you?"
Nope. expand on this please.....


@Stringsthings
"Are you ( or anyone else ) planning on making a PCB layout in the future?"
I'll do a perfboard layout in DIYLC. Which could be adapted easily.

I might do a layout in diptrace on the finished product. I'm extremely busy with work and family lately so it could be a while. Working on a never-ending work through the weekend every week stretch.

[Kipper4]

Here goes with Ver 18.

Note the envelope bias switching has changed for the non inverting input.
Essentially taking the voltage down to Gnd. (I havent measured it yet to check). It's the only way i could get it to work. Unless theres more breadboard funky junk going on.

@D.A
Included is the bjt Q2 transistor variable resistor. Thanks for the help with that D.A.
Meanwhile back to this

" I'll just leave this here for a later reference
http://www.muzique.com/schem/doctor-q.gif "

I've included it because I needed the extra 1n4148 diode clamp (D4 ver18 schematic) to make the bjt work as a variable resistor. and the Dr Q schematic in the link gave me the idea.

Glad you got an extra wrinkle Ironed out too.
No smell of carbon this time?

I'm going off the idea of an op amp lfo. but thanks for the link anyway.
I need to reread Jons reccomendations before i totally decide.

@Eric
Thanks Mate I'm sure it will be appreciated.

Any volunteers want to breadboard this version 18 ?
You can leave out the recovery switch and just make C18 220nf.
Other bjts will work for Q2 1n5088 3904 etc
Advice offered to volunteers. No sausage prizes involved. Thats right the prize is as Rhod Gilbert says "Shit all".


better not forget this

[duck_arse]

"Rod Gilbert" - the aust jazz drummer/vocalist? never mind those buzzcocks, here's rhod.

yer playing a dangerous game with C5 and C6, they really want a resistor to ground there all the time. 22k? 68k? something, although, with the 4 cap pso, it seems that leg can be left drift, with the oscillations continuing. also, I would have thought R.ENV1 would have been in series w/ base to wiper.

D4 might be eating an extra 0V6 of offset. I've just put one (LED2) in my current 'thing'.

[Kipper4]

"Rod Gilbert" - the aust jazz drummer/vocalist?
Meh NO not that one silly
this one

"I would have thought R.ENV1 would have been in series w/ base to wiper."
Yep that works too. Thanks


"D4 might be eating an extra 0V6 of offset. I've just put one (LED2) in my current 'thing'."
Hooray It's working with no D4 (ver18) Glad you persisted withthat

Ver19 demo uploading as i type.
Less part :ie, no D4 anda 3 leg pso. Go me I saved the price of a 1uf cap.

[Kipper4]

By the way did I say thanks for saying about the 47nf input caps it cut out some of the crap that was triggering the envelope..

Update I changed R23 to 68k

[Kipper4]

Why is it please that the referencing the envelope detector to Ground works for the NI input of the IC3-b, yet it has to have at least a couple of volts for the inverting input IC3-b?

Thanks

[Kipper4]

I got to thinking. Why am I doing this project. Isn't it just something that can be done with a digital delay.
The answer is no.
In delay the original signal is not defeated the echoes are over the top. Granted the echoes fade dependant on the settings
The delay won't speed up or slow down like the EnvoTrem.
The signal in the EnvoTrem is amplitude modulated.
Thanks to Jons threshold mod the EnvoTrem can also be used as a straight up tremolo too.

This type of project can also be applied to a vibe as Mark Hammer suggested.
Keep your eyes peeled on the recent magnavibe thread Mark.

I've enjoyed doing it.

Last night. Was messing with the op amp lfo. No luck so far. I'm struggling to get it respond as fast as a phase shift oscillator with the present envelope detector arrangement.
I opted for a single op amp example to mess with, this might have been a mistake.
There's more work to do in that dept.
All suggestions and previous experiences welcome and thanks for all the help so far guys.
You are diamonds.