Dunlop - UV-1 - Univibe - revision A 1997  [schematic]

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

blackbunny wrote:
Tonetweaker wrote:lolbou ~ No hijack intended... but I wanted to let you know that I took the UV1SC apart tonight and created a thread for the gutshots. Enjoy!

I haven't actually taken my UV1 apart, but I'd suspect the two units share a bit of common circuitry.
Nice shots. It looks like there may be a little less circuitry than the UV-1....have Dunlop changed their approach and re-designed the UV-1 as a less complicated circuit?
Thanks, BB.

I believe the UV1 has been discontinued by Dunlop, so I'd suspect that the UV1SC is being marketed as a somewhat simplified (and cheaper) replacement. I tend to use the UV1SC as more of a set-it-and-forget-it chorus, but for a real Uni-Vibe effect, there's no replacing the expression pedal with the UV1. I just love fiddling around with it. :mrgreen:

What's funny is that Musician's Friend still carries the expression pedal, but not the actual Uni-Vibe... The UV1SC doesn't have an expression input.


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Post by Tonetweaker »

I stand corrected. Musician's Friend shows the UV1 as discontinued, but both the UV1 and the expression pedal are still available on the Dunlop site... for a small fee. :shock:

UV1-US UNIVIBE EFFECT

UV1FC UNIVIBE FOOT CONTROL

For those prices, I would have just paid Mr. Trower to play a gig at my house. :lol:

Ironically, I can't find the UV1SC on Dunlop's site... but it's still readily available at Musician's Friend. Go figure.
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Post by blackbunny »

Tonetweaker wrote:I stand corrected. Musician's Friend shows the UV1 as discontinued, but both the UV1 and the expression pedal are still available on the Dunlop site... for a small fee. :shock:

UV1-US UNIVIBE EFFECT

UV1FC UNIVIBE FOOT CONTROL

For those prices, I would have just paid Mr. Trower to play a gig at my house. :lol:
Oh yeah, and they're even more expensive here in Australia.

Late last year there were some large online stores listing UV-1 & footcontroller pair for around $950, without mentioning that they were clearance stock of discontinued products! Merry Christmas suckers!

When they get down to $200 for the pair I will buy a UV-1 and foot controller as back-ups for my old 1995.
Not holding my breath waiting though.

Anyone want to do a layout for a UV-1 clone?

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Post by Tonetweaker »

blackbunny wrote:
Tonetweaker wrote:For those prices, I would have just paid Mr. Trower to play a gig at my house. :lol:
Oh yeah, and they're even more expensive here in Australia.

Late last year there were some large online stores listing UV-1 & footcontroller pair for around $950, without mentioning that they were clearance stock of discontinued products! Merry Christmas suckers!

When they get down to $200 for the pair I will buy a UV-1 and foot controller as back-ups for my old 1995.
Not holding my breath waiting though.

Anyone want to do a layout for a UV-1 clone?
Well, the Dunlop MSRPs are ridiculous. I'm sure you could do better on a retailer's site that still carried them. I bought my UV1 & FC "like new" on eBay for a little under $200US, if I remember correctly... so there's still hope. The UV1SC does a pretty good job too... and is much more reasonably priced, at least Stateside. I think I paid around $100 brand-new for mine.

I've been looking at the Rotovibe and Deja-Vibe too... both pretty pricey. With as much money as I've spent on guitar gadgets in the last few months, I think I should probably stick to Dano knock-offs for awhile. :lol:
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Post by lolbou »

When rehousing the unit back in place, I replaced the old and crappy ribbon cable with longer length of good quality one. I added some hot glue on each PCB (main, switches and pots) to keep it straight and avoid mechanical strain.

I would suggest making so after each dismantling of the unit since spreading it on your bench WILL break wires...
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Post by blackbunny »

lolbou wrote:When rehousing the unit back in place, I replaced the old and crapopy ribbon cable with longer length of good quality one. I added some hot glue on ach PCB (main, switches and pots) to keep it straight and avoid mechanical strain.

I would suggest making so after each dismantling of the unit since spreading it on your bench WILL break wires...
Good tip, thanks. I just put mine back together and for the first time ever it doesn't 'vibe.

I guess I'll get some valuable troubleshooting practice while I'm getting it working again.
I will replace the cables first up.

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Post by Tonetweaker »

blackbunny wrote:Good tip, thanks. I just put mine back together and for the first time ever it doesn't 'vibe.
Sorry to hear that, BB. Despite being a trained technician, I always get a little case of nerves when I pull one of these things apart, for just that reason. Perhaps I'd feel a bit more at ease about it if my t/s gear was more readily accessible.

Good luck on the fix. Hope it's nothing major.


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Post by blackbunny »

Tonetweaker wrote:Good luck on the fix. Hope it's nothing major.
lolbou's tip was right on the money. I removed the cables, cleaned the connector pins, cleaned the switching jack contacts, re-connected and success.....beautiful rich Univibe chorus and vibrato.

FWIW, the build quality of these 90's UV-1's is pretty good, and the component quality is decent too.
Makes me think it might still be going strong in 20 years time.

I considered getting a Rotovibe for a backup, but I don't like the new SMD Dunlop pc boards much - they look like they're
made in China, and the copper tracks are finer than a mouse whisker.

I just replaced the board-mounted DPDT footswitch and JFETS in a Dunlop Carbon Copy delay pedal which has an SMD board....tough going even with an SMD re-work station.

Very nice sounding pedal though. I guess SMD makes sense when you want to get lots of circuitry in a small enclosure.

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Post by Tonetweaker »

blackbunny wrote:
Tonetweaker wrote:Good luck on the fix. Hope it's nothing major.
lolbou's tip was right on the money. I removed the cables, cleaned the connector pins, cleaned the switching jack contacts, re-connected and success.....beautiful rich Univibe chorus and vibrato.
Excellent. Glad it wasn't a serious problem. :thumbsup
blackbunny wrote:FWIW, the build quality of these 90's UV-1's is pretty good, and the component quality is decent too.
Makes me think it might still be going strong in 20 years time.
Absolutely. I thought the same thing when I cracked my UV1SC. Well manufactured and nice board design. I don't think it'll fail unless I try really, really hard to screw it up... :lol:

blackbunny wrote:I considered getting a Rotovibe for a backup, but I don't like the new SMD Dunlop pc boards much - they look like they're
made in China, and the copper tracks are finer than a mouse whisker.

I just replaced the board-mounted DPDT footswitch and JFETS in a Dunlop Carbon Copy delay pedal which has an SMD board....tough going even with an SMD re-work station.

Very nice sounding pedal though. I guess SMD makes sense when you want to get lots of circuitry in a small enclosure.
Ugh. Don't tell me that. I just bought a Carbon Copy about a month ago... and several of it's MXR small-box cousins. I bought most of them brand-new, so if they don't hold up well... me and someone at Dunlop are going to have a nice, long heart-to-heart talk... :lol:

clapointe wrote:Question for you guys :

I can't get my footcontroller to turn of the vibe effect , it will only ramp the speed up or down !!!! The Uni-Vibe footswitch with turn off the effect(Vibe sound) ! How do I know if it's the Uni-Vibe or the footcontroller at fault ?
Wait a minute. :shock:

Turn it off? What the hell kind of blasphemy is that? :?

Just kidding... :lol:


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Post by blackbunny »

Tonetweaker wrote:I just bought a Carbon Copy about a month ago... and several of it's MXR small-box cousins. I bought most of them brand-new, so if they don't hold up well... me and someone at Dunlop are going to have a nice, long heart-to-heart talk...
I found some info on DIY stompboxes about problems people were experiencing with the early Carbon Copy pedals.
There were many failures in J177 SMD JFET's in the switching circuit caused by static electricity, and Dunlop eventually "leaked" a factory fix and upgrade through the forum.

That info saved my tail, because support for out-of-warranty Dunlop pedals is nearly nonexistent here in Australia.

Your new Carbon Copy should be trouble-free; new builds have the upgraded circuit.
Tonetweaker wrote:Turn it off? What the hell kind of blasphemy is that?
It is very addictive indeed when your Univibe is vibin'!

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Post by Tonetweaker »

blackbunny wrote:Your new Carbon Copy should be trouble-free; new builds have the upgraded circuit.
Excellent news. That one made the main pedal board, so I'd hate to have it crap out on me...
blackbunny wrote:It is very addictive indeed when your Univibe is vibin'!
Absolutely!
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Post by clapointe »

Besides the Vintage/Modern switch , what's the difference between the 95 model vs. 2003 model ?

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Post by lolbou »

Can you elaborate on these models, I mean, what do these refer to? AFAIK, the latest Uni-Vibe has the Vintage switch too...
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Post by blackbunny »

clapointe wrote:Besides the Vintage/Modern switch , what's the difference between the 95 model vs. 2003 model ?
My 1995 UV-1 doesn't have the "Vintage" switch, and has a different PCB layout with less CMOS switching IC's and some different (higher gain) transistor types, as I mentioned in an earlier post.

I have A/B'd mine against my friend's late model UV-1; they sound quite similar with my guitars, which have active on-board preamps and low output impedance.

Playing my friend's Stratocasters with Fralin and Texas Special (passive) pickups, the volume control interacts better in the Vintage position of the newer UV-1. Also, the Vintage position sounds a little nicer than the Modern position when using a Vox 847 or Crybaby wah in front of the UV-1.

I guess Dunlop were trying to get closer to the tone of the original UniVibe and the way it interacts with passive pickups by fitting the Vintage switch, but I haven't compared either the 1995 or the 2003 to a really old one, so I can't say how close it gets.

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Post by lolbou »

95 is BEFORE 97... :slap: At times I'm a real dumbass...

Thanks for the input blackbunny!

Mine has a bit of white (pink?) noise... I don't really know if this can be somehow related to the CMOS switching or not though...
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Post by clapointe »

When you guys use the Dunlop 18vt power adapter do you get a alot of background noise ??? I have two new Dunlop 18vt adapters and BOTH add nosie to my effects chain and amp !

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Post by blackbunny »

My Dunlop 18v plugpack was noisy as well. I made my own regulated 18vDC supply using an LM317T adjustable regulator and some nice Nichicon electro filter caps. Big reduction in noise and hiss.

I'm not sure if there would be enough room inside the Dunlop 18v plugpack plastic case to fit quality regulation, so I thought it would be easier to build my own.

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Post by clapointe »

blackbunny wrote:My Dunlop 18v plugpack was noisy as well. I made my own regulated 18vDC supply using an LM317T adjustable regulator and some nice Nichicon electro filter caps. Big reduction in noise and hiss.

I'm not sure if there would be enough room inside the Dunlop 18v plugpack plastic case to fit quality regulation, so I thought it would be easier to build my own.

I'm thinking about buying a Dunlop DC Brick or maybe an Voodoo Lab PP-2 and see if that clears up the NOISE issue !

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Post by lolbou »

But only the CMOS parts get the 18VDC from the adapter. The audio in the circuit gets its power from the 15V regulator inside.

And A+ is kinda filtered with the RC network, isn't it?

I have to test another 18V to hear...
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Post by clapointe »

lolbou wrote:But only the CMOS parts get the 18VDC from the adapter. The audio in the circuit gets its power from the 15V regulator inside.

And A+ is kinda filtered with the RC network, isn't it?

I have to test another 18V to hear...
I'm pretty sure it's the Dunlop 18vt adapter ! If I turn on my amp and ONLY plug in the 18vt apater I can hear the added background noise ! :-(

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