Dunlop - JD-4S Rotovibe  [schematic]

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.
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puppiesonacid
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Post by puppiesonacid »

schematic? mods?

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The Rotagilla
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Post by The Rotagilla »

Web legend says Clay Jones modded a couple of these and they sounded killer. No documentation to support this though.
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frankg
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Post by frankg »

i wanna no more, the buffer sucks on loud guitars

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drfrankq
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Post by drfrankq »

anyone know about that buffer mod, it distorts on clean, thanks! - frank
PS this is my first post

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drasp
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Post by drasp »

I've got one of these turds sitting on the bench, belongs to a friend. Some crazy problem with the switching that I'm having trouble sorting for him. Would be happy to supply pix, test, probe, whatever - anyone know these well?

Snapped a few pix for you to peruse!
DSCF0004.JPG
DSCF0003.JPG
DSCF0002.JPG
Also found the schematic @ MEF.
DunlopRotovibe-1.jpg

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lolbou
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Post by lolbou »

Thanks for the schem...

The pics really look like the dunlop Univibe (reissue)... The CMOS circuitry is maybe less big...

I'm about to get a broken (but fully implemented) univibe PCB, so I'll check that!

By the way, any info about the Univibe reissue? The PCB I'll get comes from a friend of mine who had a broken unit. He brought it back to the local store, who asked the customer support. And for something like 50$ (to be confirmed), he got a brand new full PCB, and they did not keep the older one ( :D )...
- Are you a mod or a rocker?
- Uh, no, I'm a mocker.

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HydrozeenElectronics
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Post by HydrozeenElectronics »

I really like my Rotovibe but one thing I found that makes a big difference is: I built a buffer for my Fuzz Face so I could run my Wah into it. Well if I put the buffer in front of my Rotovibe it sounds much better very "Woodstock" ere Hendrix.

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puppiesonacid
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Post by puppiesonacid »

i always wanted to modify it so it sounded more like a univibe and less like a chorus/vibrato....

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Post by sevinisthenumber »

this was one of my favorite vibes but the bypass always drove me bonkers. I would love to figure out how to TB it one day. For now im rocking a re-cased cool cat vibe! KILLER!
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HydrozeenElectronics
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Post by HydrozeenElectronics »

Ya the bypassed tone is weak so I built a looper pedal and now I can leave it in a nice setting and bring it in and out of the loop any time I want it.

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Post by Bside2234 »

I just leave mine on all the time.

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Post by nooneknows »

I think the Rotovibe is the Best univibe type pedal: althoughe the original univibe hs that unique kind of watery effect, there's something in the rotovibe that simply... "rocks" (and it's not only the pedal...).
My favourite chain EVER is stratocaster > tubescreamer > Rotovibe > Jcm800 single channel head+4x12.
The only reason I don't use it anymore is that a friend of mine fried the suply section of my unit ( :( ), since then I'd never been able to restore it completely, there a strong waving hiss on the background (even if the pedal is bypassed) on the other pedals of my board, probably coming from its supply...

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Post by nooneknows »

drasp wrote:IAlso found the schematic @ MEF
excuse my ignorance, what is MEF?

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Post by ik6gpy »

nooneknows wrote:
drasp wrote:IAlso found the schematic @ MEF
excuse my ignorance, what is MEF?

Music Electronics Forum :wink:

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Post by nooneknows »

reviving a zombie thread ....

I was reading the schematic , in the rotovibe the four stage cap values are not the 'common' univibe values , I think that is part of the rotovibe characteristic sound.

Has anybody ever tried these values in other unit such as phase 90 or some univibe clone ?

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