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.

Re: Dunlop - Univibe - UV-1 (Rev.A 1997) - schematic

Postby blackbunny » 10 Mar 2011, 00:39

clapointe wrote:
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 ! :-(


It sounds like your 18v adapter may be faulty, if it induces noise into your amp through the AC mains even without the UV-1 plugged in. My Dunlop 18v supply was too noisy for my liking, but I don't think it did that. It was a small but heavy analog one.

Yours isn't a switch-mode adapter is it? If it is, it will be very small and light weight.

I will check my old 1995 UV-1 again to see if it has the filter and regulator network inside, like lolbou's diagram.

It certainly should provide good filtering and regulation for the IC's and transistors in the signal circuit if it's inside the box.
User avatar
blackbunny
Resistor Ronker
 
Posts: 379
Joined: 07 Jan 2011, 08:41
Location: the garage
Has thanked: 246 times
Have thanks: 110 times

Re: Dunlop - Univibe - UV-1 (Rev.A 1997) - schematic

Postby clapointe » 10 Mar 2011, 04:11

One maybe but two Dunlop 18vt adapters ? One's old and came with the Univibe and the other is brand new (3 days old ! ) ? I've heard that players have noise issues with the Dunlop 18vt adapters !
clapointe
 
Posts: 23
Joined: 25 Aug 2010, 18:41
Has thanked: 0 time
Have thanks: 0 time

Re: Dunlop - Univibe - UV-1 (Rev.A 1997) - schematic

Postby lolbou » 22 Jul 2011, 23:13

Still I don't get what the two trimpots TP1 and TP2 are to be set at... I somehow assume that the previous owner has tweaked these to "repair" it, and the sweeping is like assymetrical...

Any advice on this?

trimpots.gif
You do not have the required permissions to view the files attached to this post.
- Are you a mod or a rocker?
- Uh, no, I'm a mocker.
User avatar
lolbou
Old Solderhand
 
Posts: 2710
Joined: 18 Nov 2008, 22:38
Has thanked: 346 times
Have thanks: 234 times

Re: Dunlop - Univibe - UV-1 (Rev.A 1997) - schematic

Postby lolbou » 23 Jul 2011, 00:21

OKay, I should have scoped these earlier... :slap:

TP1 biases the optocoupler to adjust frequency range. I set mine to have 5Hz at max speed. Lowest speed setting is now .55 Hz, which is normal with the Univibe LFO (between 0.7 and .3 Hz).

Still I don't know what TP2 is all about. :scratch:
- Are you a mod or a rocker?
- Uh, no, I'm a mocker.
User avatar
lolbou
Old Solderhand
 
Posts: 2710
Joined: 18 Nov 2008, 22:38
Has thanked: 346 times
Have thanks: 234 times

Re: Dunlop - Univibe - UV-1 (Rev.A 1997)

Postby lolbou » 24 Jul 2011, 17:37

Updated to rev. 2.3. The 22M in the driver circuit's voltage divider was wrong :oops: : I read the 5 band color code backwards! :slap: It's a 75k instead, which makes much sense...
- Are you a mod or a rocker?
- Uh, no, I'm a mocker.
User avatar
lolbou
Old Solderhand
 
Posts: 2710
Joined: 18 Nov 2008, 22:38
Has thanked: 346 times
Have thanks: 234 times

Re: Dunlop - Univibe - UV-1 (Rev.A 1997)

Postby Effectsiation » 28 Jul 2011, 20:15

I have two Dunlop UV-1 pedals at home. The first (broken) one has no vintage switch and must be the '95 model that you guys are referring to. The other was the 2003 model that I bought (with vintage switch) after the first one broke. I'd be happy to take pictures of both if that would help anyone.

I can confirm that there are in fact two separate Dunlop UV-1 18v adapters that came with the different versions of this pedal. If I still have both (I might have sold the one from the broken pedal to try to recoup costs) I will take pictures, but I remember them being different dimensions. There is also a different Dunlop 18v adapter that they use the power the DC Brick.

I remember contacting Dunlop about fixing the first UV-1, and they said that they would not fix it.
User avatar
Effectsiation
 
Posts: 43
Joined: 09 May 2008, 19:18
Has thanked: 7 times
Have thanks: 0 time

Re: Dunlop - Univibe - UV-1 (Rev.A 1997)

Postby filsek » 09 Oct 2012, 18:03

Hi!

This is my first post on this forum, so I apologize upfront if I did anything wrong. First of all, sorry for refreshing such an old topic. Also I'm not native english language user, so excuse me, if I'm hurting that language.

I have an UV1 and I'm faceing an annoying problem. The SPEED value got stuck. It has stopped on some value, and doesn't want to go any less or more. I tried to use an expression pedal to move it, but still... it's not doin' anything. I've resoldered pots, jacks and all of the wires to exclude any bad connection. Stil, no response from SPEED knob.
In act of desperation, I've ordered all of the logic IC's. I'm willing to replace them, but I'm not sure if this will do any good. I know this is a very non engineer method: something's broken - go replace everything.
I've tried to study schematic with all of the logics, but it's a little bit over my knowledge.

Also, if anydoby have measured proper voltages on transistor who are drived by bias potentiometer and have proper values of those, please, don't hasitate to publish them in here. Thank You upfront.

Thank You if You have read that, and thank You even more, if You know the solution for my problem. Or the reason why UV1 is beeing so bad for me.

Best,
filsek
filsek
 
Posts: 4
Joined: 09 Oct 2012, 17:51
Has thanked: 0 time
Have thanks: 0 time

Re: Dunlop - Univibe - UV-1 (Rev.A 1997)

Postby sinner » 09 Oct 2012, 18:20

filsek wrote:
Also, if anydoby have measured proper voltages on transistor who are drived by bias potentiometer and have proper values of those, please, don't hasitate to publish them in here. Thank You upfront.



All I have is just Shin-Ei 60's era Univibe voltages, but that's the different type of circuit AFAIK
sinner
Old Solderhand
 
Posts: 4811
Joined: 06 Nov 2008, 18:16
Location: ...no more
Has thanked: 1239 times
Have thanks: 1099 times

Re: Dunlop - Univibe - UV-1 (Rev.A 1997)

Postby lolbou » 09 Oct 2012, 20:13

filsek wrote:I've resoldered pots, jacks and all of the wires to exclude any bad connection.
Check also that the connections made in the EXP pedal jack itself (the "springy" ones that lift up when a jack is plugged in) are functional. These are supposed to be shorted when no jack is plugged in. The one I bought second hand (known faulty) had jumpers across the jack lugs to make these connections always on, disabling the EXP pedal use. Changing the whole jack solved the issue.

Up to your continuity tester!! :wink:
- Are you a mod or a rocker?
- Uh, no, I'm a mocker.
User avatar
lolbou
Old Solderhand
 
Posts: 2710
Joined: 18 Nov 2008, 22:38
Has thanked: 346 times
Have thanks: 234 times

Re: Dunlop - Univibe - UV-1 (Rev.A 1997)

Postby filsek » 09 Oct 2012, 21:08

Yes, I'm awared of functionality of jack sockets. Allways, when checking non working effect I start with the connectors and pots. The exp jack is fine, I've tested it with multimeter.
Struglin' with that one badly. Can't wait to receive ordered component to replace them and see what it will give.
filsek
 
Posts: 4
Joined: 09 Oct 2012, 17:51
Has thanked: 0 time
Have thanks: 0 time

Re: Dunlop - Univibe - UV-1 (Rev.A 1997)

Postby lolbou » 09 Oct 2012, 21:19

Check for cold solder joints at the optocoupler?

I did repair one with a locked speed issue, and I measures weird voltages at the opto's LED lugs.

I desoldered it, and placed a real LED instead. I did get the oscillation varying along with the speed knob.

I then checked the opto's LED with my Peak DCA55, and it appeared nice.

I resoldered the LED part of the opto in its place and bingo!

:?: :scratch: :blackeye
- Are you a mod or a rocker?
- Uh, no, I'm a mocker.
User avatar
lolbou
Old Solderhand
 
Posts: 2710
Joined: 18 Nov 2008, 22:38
Has thanked: 346 times
Have thanks: 234 times

Re: Dunlop - Univibe - UV-1 (Rev.A 1997)

Postby filsek » 09 Oct 2012, 22:35

lolbou wrote:Check for cold solder joints at the optocoupler?


I did resolder tho joints. Put some new solder and stil nothing. Locked on the same speed. I'll try Your trick with installing LED instead. Hope that will give anything. If not, there's just waiting for a delivery of logics. I wonder byt the way if that will help anyhow.

Thanks for responding.
filsek
 
Posts: 4
Joined: 09 Oct 2012, 17:51
Has thanked: 0 time
Have thanks: 0 time

Re: Dunlop - Univibe - UV-1 (Rev.A 1997)

Postby filsek » 10 Oct 2012, 10:14

Allright... I tried the trick with the LED. It wasn't working at all. Then, unfortuneatly, whole unit stopped going to bypass/effect. What I mean is the control LED from eff/bypass doesn't glow at anytime. The effect LED is allright. So probably, by accident I've short circuted something and this is how it is now.
I found out, that there is no voltage on Q10 and Q12. Propably bcs it's all the time in bypass mode now.... God forgive me what I've done.
filsek
 
Posts: 4
Joined: 09 Oct 2012, 17:51
Has thanked: 0 time
Have thanks: 0 time

Re: Dunlop - UV-1 - Univibe - revision A 1997

Postby Slash_83 » 09 Dec 2015, 14:35

Image
Slash_83
 
Posts: 11
Joined: 07 Sep 2011, 09:54
Has thanked: 0 time
Have thanks: 0 time

Re: Dunlop - UV-1 - Univibe - revision A 1997

Postby Slash_83 » 09 Dec 2015, 14:36

Hi guys,

Do You know if that resistor is normal?? I bought a used univibe. What is it?
Slash_83
 
Posts: 11
Joined: 07 Sep 2011, 09:54
Has thanked: 0 time
Have thanks: 0 time

Re: Dunlop - UV-1 - Univibe - revision A 1997

Postby lolbou » 09 Dec 2015, 15:58

It's not stock to me. From what I see, I would say that this resistor goes between the modulated end of the bulb ( upper connection on your pic) and ground (lower connection on your pic).

Now why? Has the bulb been changed?
- Are you a mod or a rocker?
- Uh, no, I'm a mocker.
User avatar
lolbou
Old Solderhand
 
Posts: 2710
Joined: 18 Nov 2008, 22:38
Has thanked: 346 times
Have thanks: 234 times

Re: Dunlop - UV-1 - Univibe - revision A 1997

Postby Slash_83 » 09 Dec 2015, 16:25

I dont know.. This is My question too.

Is a resistor between The resistor near q16 and c23 (Ground).


Any suggestion? Is this effect "not original" i suppose.. In this conditions. I can See traces of flux over The ldr and bulbs
Slash_83
 
Posts: 11
Joined: 07 Sep 2011, 09:54
Has thanked: 0 time
Have thanks: 0 time

Re: Dunlop - UV-1 - Univibe - revision A 1997

Postby lolbou » 09 Dec 2015, 16:29

Any added component on the upper side of PCB? If the unit works, just leave it?
- Are you a mod or a rocker?
- Uh, no, I'm a mocker.
User avatar
lolbou
Old Solderhand
 
Posts: 2710
Joined: 18 Nov 2008, 22:38
Has thanked: 346 times
Have thanks: 234 times

Re: Dunlop - UV-1 - Univibe - revision A 1997

Postby Slash_83 » 09 Dec 2015, 16:35

It seems that there isnt Any other mod..

How much differents ldr affects sound??
Slash_83
 
Posts: 11
Joined: 07 Sep 2011, 09:54
Has thanked: 0 time
Have thanks: 0 time

Re: Dunlop - UV-1 - Univibe - revision A 1997

Postby lolbou » 09 Dec 2015, 16:46

Different LDRs? The dark/light resistances may be different, and the sensitivity (time needed to go from dark value to light value) may be different too...

I guess that the extra resistor is just limiting the current in the bulb when Q16 is OFF. If the light bulb has been changed, then maybe the new one wasn't made to cope with the 15V?
- Are you a mod or a rocker?
- Uh, no, I'm a mocker.
User avatar
lolbou
Old Solderhand
 
Posts: 2710
Joined: 18 Nov 2008, 22:38
Has thanked: 346 times
Have thanks: 234 times

PreviousNext

Return to Modern Stompbox Effects (1975 - ...)

Who is online

Users browsing this forum: Google Feedfetcher, lars-musik, P-Trash, sporow, Svullgo and 8 guests