preliminary wobbletron vero

[pinkjimiphoton]

i did this quick tonite, cuz i'm thinking about building one of these things...i'm a sucker for vibrato that bends pitch, and well...

anyways, i was wondering if anyone more knowledgeable could take a peek at it and tell me if it looks ok...

i'm planning on shrinking it some still, there's a lot of wasted vero on this mockup...



as always, thanks in advance...
peace
jimi

[GuitarTek86]

any progress on this? I'm looking to build a vibrato pedal. Schematic?

[pinkjimiphoton]

this pedal never worked for me. so i quit pursuing it. if ya want something similar, google up magnavibe clone. nice unit, similar, dead easy and works.

[GuitarTek86]

awesome! thanks a ton. just wondering, are the 1nf's film, or electrolytic? there's no polarity shows on the plot. Thanks again!

[pinkjimiphoton]

you mean the 1u? those looking kinda caps in diy layout creator are always electros, the shaded part is the negative side.

i LOVE this pedal...it and my fuzzface are probably my most used.

[GuitarTek86]

sorry. that's what I meant. I never noticed the side was shaded. thanks!

[deadastronaut]

@jimi, hi man, have you a soundclip of the magna vibe, clean and distorted?...

oh , and a schematic ...i'll have a go at doing a pcb version if it sounds cool...cheers man, rob.

[pinkjimiphoton]

hi rob, i don't really have the capabilities to do clips at the moment, but will try to get some for ya if my girl ever gets off my laptop, lol..

i don't think i have a schematic, but will look...gimme a sec...wow! you're in luck rob!!

here's the bom:

Magnavibe Parts List

C1       0.22uF
C2       0.1uF
C3       0.22uF
C5       1uF
C6       1uF
C7       1uF
C8       47uF
D1       Size of your choice
D2       1N4001
DEPTH    25kB
LDR      LDR
Q1       MPSA18
Q2       MPSA18
R1       2.2M
R2       2.2K
R3       4.7M
R4       7.5K
R5       7.5K
R6       1.5M
R7       2.2K
R8       27K
R9       10K
R10      1.5M
R11      1.8K
RLED     4.7K
SPEED    25kB

here's the schem, layout, and a toner transfer







fwiw, i built the above vero, worked perfectly right out of the gate...run it with bat, lasts forever, and is clean and quiet with a wart. it's basically a wobbletron that works.


have fun, brothers!

[deadastronaut]

wow, nice one jimi.....  i'll give it a breadboard....thanks for that!..


edit: hmmm wonder if it would be ok with other npn's...?..

[pinkjimiphoton]

i think as long as the gain is high enough, yah... just got a shipment of mpsa18's, some have hfe's in the 700's 

tried 'em in a jh1 clone i just built, they are fuzzy as heck...i ended up reversing stuff and making it pnp instead with some new old stock russian ge trannys instead. real nice!!

my suggestion, is try it...on the breadboard. i KNOW the mpsa's work....all i can say, bro. unlike the wobbletron.

[deadastronaut]

yep....breadboard time i think....cool, cheers man.

[nocentelli]

I'd love to hear from anybody who has got the wobbletron to work - I actually built a working Magnavibe first, and then couldn't get the Wobbeltron to wobble in the slightest, but do I like the idea of getting the same result without messing around with LDRs - No offence Rob.

On the same subject, I've got the Light Wah on the breadboard now (works and sounds great, btw, thanks Rob) and I'm very interested in the idea of using the LFO section from the Lightwah with the Magnavibe vibe section: The lightwah LFO goes a good bit faster, and waaaay slower than the Magnavibe's rather limited range - Might be good....

[deadastronaut]

ha ha, no  offence taken...

yeah i was just reading about the problems people had getting the wobbletron to work (wobble)...

good idea on the lfo btw....

draw up a schemo?...

[pinkjimiphoton]

yah, and post it, cuz i wanna build it!! lol

i built a wobbletron. everything was RIGHT. the VOLTAGES were GOOD. the damn light flashed, the transistors seemed to be modulating, didn't do a damn thing to the sound whatsoever.

but the magnavibe is hip...would love to hear it have more range..it's kinda univibish, but the pitch bend part is what's so cool...it is a great and organic alternative to chorusing.
i think you'll dig it.

[tiges_ tendres]

I just built a Magnavibe from the above vero layout. Sounds a little tame compared with some of the samples I've heard. I only had 20k pots on hand, and the only MPSA18's I had were pulled from old builds. Also, does anyone have the specs on what kind of LED LDR combo they used? I have a VTL5c3 in there currently.

Voltages would also be killer if someone has them.

[pinkjimiphoton]

i just used an led and a photo resistor, stuffed 'em in a drinking straw about 3/16ths of an inch apart, then sealed it in shrink wrap. worked great.

can't get ya voltages, the pedal's on the truck.

20 k should be fine for the pots.  you may want to put in some different mpsa18's, their gain is all over the place.

it's a rather subtle effect, don't expect whammy style pitch bends bro. i absolutely love mine, that and my fuzzface are my most used pedals.

i'd like to get one that was stereo, so one bends up while the other bends down...rob, you're the mad scientist, do you think that could be done?

[digi2t]

i'd like to get one that was stereo, so one bends up while the other bends down...rob, you're the mad scientist, do you think that could be done?

See "Stereo Panneur" at 4MS pedals. I bought the kit, built it, love it. You can sync the two sides, or run them apart at different speeds. Not the same effect, but maybe borrow the circuit section for the stereo sync/symmetry?

Cheers,
Dino

[pinkjimiphoton]

heh heh...blowin' off my brother, gonna go hit the part store!! get the klon and the vocalizer done..lol

i just figured with all of rob's experiments, he'd be the guy to ask about it...'

i have to watch the GAS right now, dino...too much equipment, and no money left!!! lol   

[nocentelli]

Sounds a little tame compared with some of the samples I've heard. I only had 20k pots on hand, and the only MPSA18's I had were pulled from old builds. Also, does anyone have the specs on what kind of LED LDR combo they used? I have a VTL5c3 in there currently.

I used an ultra-bright blue LED and this LDR - http://www.musikding.de/product_info.php/info/p709_Photo-cells-24k-72kOhm--1M-.html: It's plenty deep enough for me at max depth, pretty seasick sounding.

[pinkjimiphoton]

nocentelli's vero works great...hey bud, hope ya don't mind me spreading your work around!! great pedal!