Harmonic Percolator - make one!

[amz-fx]

regards, Jack

[Phend]

Question,
In the above circuit what does R4 do ?

[Lino22]

How does Q1 work? It is not connected to DC?

[Radical CJ]

How does Q1 work? It is not connected to DC?

It is, via Q2 emitter... i think.

[antonis]

Question,In the above circuit what does R4 do ?

It limits D4 Zener current..
(only when D4 is in breakdown region..)

edit: wrong R..
R4 could be considered  a "stopper" resistor (for Perc pot set at zero Ohms) in the absence of R3..
Being 0.1% of R3, it seems to me more like it's just left forgotten there..

edit to edit:
Jimmy said for 47R resistor to be tied on pot wiper (not on any of outer lugs..)

How does Q1 work? It is not connected to DC?

[Lino22]

Thank you, me blind.

[Ben N]

Jimi's 2015 revisions are here. However that Perc circuit is configured, and whatever value the pot is, you have still have that silly 47R hanging around at the tail end of a resistance at least 1000x its value with no apparent purpose.

Paging Mr. Photon!

[Phend]

Fortunately Mr. Photon probably has all of his notes.
Detailing the excellent experimental permutations he has done for prosperity on the Harmonic Perculator.
And he certainly has put in hours of work on this.
The notes are stored in his dungeon . Cool place that.
Thanks Jiimi. !
(See Members Only)

[pinkjimiphoton]

ok, ok, what?

i will post the final juerg when i go upstairs

[pinkjimiphoton]

Question,
In the above circuit what does R4 do ?

it limits the range of the pot so the pot won't smoke if it is shorted

[pinkjimiphoton]

heres the vero layout and schematic of the last incarnation
the 47r resistor is so ya don't smoke the pot if ya turn it all the way down. if ya short the pot, there can be enough juice to smoke the pot.

and obviously, the LAST thing i want is anybody smoking pot(s) 

the wiper ain't tied to the spare lug cuz this way it acts as a variable resistance with the taper of that half of the pot, which is different than the taper if the wiper was tied to one side or the other. when ya do that, half the pot travel doesn't really do much. without it, the resistance change works better... BUT the pot can smoke. trust me. i am NOT afraid to let the magick smoke out, ever.
that's why the resistor is there. that way the resistor is big enough to protect the pot, and small enough to not really matter. also can help cuz some q's can oscillate. this takes the squeeky away.

the basic idea was a simplified perc based on tim escobedo's jerk, with a nod to jurgen haible <rest in power> as well...
by @#$%ing with the bias of the two q's independently, you can get quite a lot of tones out of the mother.

the shared emitters is where the magick happens. that's the percolator. the npn/pnp are a push pull combo and the big @#$%in cap is the well where the brew percolates and is stored. somehow it seems to phase the bad harmonics, reinforce the good harmonics and store the signal in the cap.
i remember @#$%ing with an all ge version once, and if ya pulled either q, it would still work until that big cap discharged.

do i know what's goin on? not a @#$%in clue. but that's my guess, and i'm stickin' to it.

if you guys looked on the forbidden forum <which i support financially like i do this one> you would have found the following.

have fun. the vero is vero-fied and works great. i sold a few a year ago or so on facebook, of all places.

weird planet. go figure.

[pinkjimiphoton]

video. def not safe for work due to, well, sex, drugs, rocknroll, foul language, dog n pony shows, and god knows what else

https://www.youtube.com/watch?v=66e9lAEaX7w&t=2s


ok, back to smoking funny veggables and bReaking stuff....

[Ben N]

Question,
In the above circuit what does R4 do ?

it limits the range of the pot so the pot won't smoke if it is shorted

But, but, but, Jimi, the pot is also in series with a 47k resistor. Does tacking on 47R make any meaningful difference?

[antonis]

But, but, but, Jimi, the pot is also in series with a 47k resistor. Does tacking on 47R make any meaningful difference?

I presume Jimi has 47R resistor as a current limiter..
(9V/47R = 190mA) but then 47R should be rated at 2W, at least..

P.S.
Unless I need another cup of coffee, I can't see any obvious reason for particular pot to be shorted but I suppose there are plenty of shorted/burned out pots into Jimi's junkbox..

[Ben N]

I presume Jimi has 47R resistor as a current limiter..
(9V/47R = 190mA) but then 47R should be rated of 2W, at least..

Same question. 9v/47kΩ = 1.915e-4 Amps. Current is not a problem.

[antonis]

Same question. 9v/47kΩ = 1.915e-4 Amps. Current is not a problem.

On behalf of Jimi..

Particular pot could be shorted by accidentaly connecting its upper lug (or wiper) to +9V..
(leaving 47k resistor out of the game..)

[Phend]

Off on a Tangent...
Jimi mentions that the 47uF Tant Cap might be responsible for some of the sound effect in the Harmonic Peculator.  Years ago I built a RS led flasher using a LM3909 ic (still have). You could change the flash rate buy changing the ele capacitor value.  Wondering Out Loud, has a timer chip as such ever been adapted to a simple fuzz circuit (some how) to add an (unknown effect) ? The supply instead of going to an led would go to one of the tranistor(s) ? 

[pinkjimiphoton]

47u tantalum? i don't think i've ever actually used a tantalum cap.

only thing i use is mcc's or electros, other than in guitars, where i tend to like greenies.

i just use bog standard electros, rated for generally 25 to 50 volts. including on this circuit. i'd never spend the bread on tantalum, they melt and wear out and don't really save space or money or make any diff i ever heard in literally any circuit i ever built....

at this point that's 3 4 inch thick binders overflowing of circuits.

[pinkjimiphoton]

Question,
In the above circuit what does R4 do ?

it limits the range of the pot so the pot won't smoke if it is shorted

But, but, but, Jimi, the pot is also in series with a 47k resistor. Does tacking on 47R make any meaningful difference?

i don't remember. try it and see. as i recall, the pot would smoke the track when down all the way. it doesn't make much dif tonally. but i think part of it comes down to how leaky the ge is. i tend to just pop 'em in and out til i like the tone, and pay no attention to gain, clocking, type, etc etc...

ears rule. always.

[pinkjimiphoton]

But, but, but, Jimi, the pot is also in series with a 47k resistor. Does tacking on 47R make any meaningful difference?

I presume Jimi has 47R resistor as a current limiter..
(9V/47R = 190mA) but then 47R should be rated at 2W, at least..

P.S.
Unless I need another cup of coffee, I can't see any obvious reason for particular pot to be shorted but I suppose there are plenty of shorted/burned out pots into Jimi's junkbox..

oh yeah. lol. ya never know. i find them cheap fake alpha's that tayda hawks can smoke if ya look at 'em funny.

i love smokin pot(s)