Debugging: Can you help me revive my Danelectro Cool Cat Vibe?

[debrad]

Hi Folks,

I am in the middle of rehousing a Cool Cat Vibe for a friend of mine.  I've managed to rehouse several Cool Cats and this one didn't look any harder...especially since so many people appear to have successfully rehoused and/or modded it in the past.

Well...not so fast!

After stripping the original components, rewiring new pots and switches, and stuffing everything into a new enclosure, my Cool Cat Vibe refuses to come to life.  I asked for some help in the Vibe rehouse thread (http://www.diystompboxes.com/smfforum/index.php?PHPSESSID=9fcdca46336851e3b42e0db7843690f2&topic=70874.140) but haven't managed to get to the bottom of things so I figured I would follow the recommendations from the DEBUGGING sticky in hopes that it might help me revive this thing (I really don't have any hair left to pull out!!!).

So...following the DEBUGGING template:

1 - What I have.......a Danelectro Cool Cat Vibe that I am trying to rehouse in a new enclosure.

2 - Links...I can't seem to find any Cool Cat Vibe schematics but understand that it MAY be based on the original Uni-Vibe

3 - How closely did I follow the original plans?  I pulled the stock pedal from the enclosure, stripped the original wiring and hardware, connected new pots, new jacks, new DC jack, and a new 3PDT switch.  As far as I can tell, I connected all the new components exactly the same as the stock wiring...with TWO exceptions.  1 - I swapped the "LED switching" and "FX OUT" sections on the 3PDT so that the PCB output and FX output are in the middle of the switch and the "LED Switching" is on the outside lugs (I figured this would make it easier to add a resister between the LED lugs to cure the pedal's famous delay issue).  2 - I added a 100K audio taper pot between the PCB output and the 3PDT switch to help control the pedal's famous "volume boost" issue.  My wiring is shown on the Dano Vibe thread linked above; however, I can post the photo here as well if it helps (just trying to keep from double posting TOO much).

4 - Part substitions...just the 100k audio pot mentioned above

5 - Ground...the Cool Cat Vibe is a negative ground pedal

6 - What does and does not work...I get my clean guitar signal at the output of the pedal regardless of whether the effect is "on" or in "bypass".  When the effect is "on" I can control the volume with the newly added 100k volume pot but none of the other pots have any affect.  The LFO bulb does NOT light when the effect is on and the LED does NOT light when the effect is on.  Having said that, if I touch the LED cathode with my fingers, the LED will light.  Similarly, when the effect is in "bypass", the LED will light if I touch the 3PDT lug in the LED section that is not wired to anything.

7 - Voltages...these are the voltages I measured on the pedal with the DC jack connected to a Power-All adaptor...all pots set to approximately 50% and 1/4" cables connected to the effect's input and output jacks:

DC Jack = 9.13

9V input on PCB = 9.12

IC # 1 (TL072C/83M/A2NR4G4)....P1=3.27
                                                 P2=3.26
                                                 P3=3.24
                                                 P4=0
                                                 P5=3.26
                                                 P6=3.26
                                                 P7=3.27
                                                 P8=6.58

IC #2 (TL072C/83M/A2NR4G4)...P1-P8 all read 0

IC #3 (not sure what this one was...but it had 3 legs on the bottom and a curved connection on the top)...left most leg = 0
                                                                                                                                                        centre leg = 0
                                                                                                                                                        right leg = 9.14
                                                                                                                                                       leg on top = 0

LED...anode and cathode = 0

LFO bulb....both sides = 0

Diode D1 (this is a "404" with several stripes on one end).................striped end = 9.07
                                                                                                   plain end = 0

Transistors:
Q1-Q10 are "L7" transistors

Q1...C=6.58
       B=2.06
       E=1.71

Q2...C=4.57
       B=2.59
       E=2.02

Q3...C=5.44
       B=1.8
       E=1.13

Q4...C=2.59
       B=1.76
       E=1.22

Q5...C=1.76
       B=1.03
       E=0.58

Q6...C=6.59
       B=2.5
       E=1.96

Q7...C=6.58
       B=2.77
       E=2.42

Q8...C=6.58
       B=2.77
       E=2.42

Q9...C=4.73
       B=2.42
       E=1.83

Q10...C=4.76
         B=2.41
         E=1.83

Q11....this was a tall transistor, curved on one side, flat on the other.  I am not sure of the polarity of this transistor so I label it as follows:

     ---------
   /            \
   -----------
  A     B     C


A = 0V
B = 0V
C = 0.01V


I also went through all of the larger "can-type" capacitors and found the following

C11...dark side of can=9.14, white band side of can=0
C12...dark side of can=6.58, white band side of can=0
C22...3.26 on one side, 0 on the other
C26...0 on both sides
C28...dark side of can=9.14, white band side of can=0
C29...dark side of can=0, white band side of can=0
C30...dark side of can=0, white band side of can=0
C32...-0.81 on one side, 0 on the other
C33...-0.82 on one side, 0 on the other

Now, I have read that the LFO driver can be an issue with vibe pedals and the fact that Q11 (which I have read on other forums MIGHT be the LFO driver) is reading 0's on all three pins definitely has me wondering what's going on there.  Having said that, my lack of knowlege and understanding for this particular schematic definitely has me scratching my head.

Truth be told, I don't fully understand how any of the +9V is getting from the DC jack to either the bulb or the LED and I can't help but wonder if I have missed some small, simple little thing on the rehouse that is preventing the delivery of power to these components.

I think those of you that have already tried to help me and I definitely look forward to any advice that the rest of you may have on this one.

Thanks in advance!

- brad -

[duck_arse]

I know nothing about this pedal, however, it is more than likely your op-amps would be running on the full (or very near) 9V appearing on your pcb. measuring on the TL072's, black to pin 4 and red to pin 8, should read around 9V, you've already lost 2V. and IC2 is very definately wrong.

can we see some photos of your board, component side and copper side? and you'll have to trace the traces from the red battery wire through to wherever, it may go to a regulator or something. C11 and C28 are both at full 9V, check with yr ohms range, POWER OFF FIRST between their (9V) pins and the pin 8's of the opamps.

[debrad]

Thanks for taking the time to have a look at this for me...I really appreciate it.

I'll have to take a picture of the "copper side" of the PCB when I get home from work tonight but here is a fairly decent shot of the component side:



Note that IC2 is the TL072C in the top right corner of the photo.  I believe that C28 is under the white wire that connects to the 3PDT's bottom right lug (the red wire underneath C28 is my +9V input) and C11 is the tall one just underneath the blue trim pot.

[duck_arse]

I'll have a look at the pic tomorrow. can you get a number off (Q11?) the tall one next the trimpot?

[debrad]

As requested...

Here is the "copper" side of the PCB (BTW, I now see that the +9V power coming in at J1 should get to the LED at J2 via C11...correct?):




and here is another shot of the "component" side:




As requested, I checked the text on C11...that reads, "SXT CD110  470uf 16V" (C28 reads 100uf 16V in case you wondered about that one and I think C29 might be the same as C28 but it's too cramped beside C28 to read it).

I also check the continuity between the two capacitors in question (C11 & C28) and the two TL072C IC's:

C11(+pole) -> IC2(pin8).....slight movement of my analog MM at Rx100 (~45 X 100 = 4.5k)
C11(+pole) -> IC1(pin8).....about 600 ohm

C28(+pole) -> IC2(pin8)...barely any needle movement
C28(+pole) -> IC1(pin8)...about 600 ohm

By comparison, I did the same test with C29:
C29(+pole) -> IC2(pin8)...zero resistance

- brad -

[Beo]

My recommendation is to put it back to stock and get that working, then add one mod at a time. If you think you might have the switch wiring wrong, take it out and hook up jacks directly to the in/out pads. But really, a continuity test should confirm if you have the stomp wired right. After that, an audio probe works wonders. A lamp is just like an led... test it with a resistor and dc voltage.

Alternatively, buy a second one, mod that one a mod at a time, then fix your first one using the second as a reference. I have two... one that I modded for the typical fixes, and the other that I intend to put in a wah enclosure some day.

[duck_arse]

^ what beo says.

those black wires on J3, where do they go? and it was the numbers on Q11 I was interested in, I just had no idea of the part numberings. you have confirmed the resistance and workings of each pot, from their pcb spots, yes? I'll havva look at yr pics tomorrow, again.

[debrad]

Thanks for the suggestions.  I will definitely double check the pot resistance...I did check each to make sure there was continuity between each lug and the respective pins on the PCB but didn't measure resistance between lugs in the full clockwise and counterclockwise postions.

I will also try to decipher the text on Q11 (sorry for misreading that!).  It is very close to C11 which makes it hard to read but I'll do my best to GENTLY bend it back enough to get the numbers.

As for the black wires on J3, the "top" wire is the PCB output so that goes to Lug 3 on the 100k volume pot that I installed (Lug 3 of the volume pot goes to the 3PDT switch and Lug 1 goes to ground).  The "bottom" black wire is the LED cathode pin which goes to the LED section of the 3PDT switch.

Barring any other suggestions, I guess I will begin plans to remove the 100k volume pot and wire the PCB output directly to the 3PDT switch...that is the only MOD that I have implemented so far.  So many others have done this mod that I assumed it was pretty straightforward and I thought the fact that I have great volume control when the effect is "on" indicated that this part of the circuit was the only part working correctly; however, it is probably wise to start from square one and MOD from there.

On a side note, I was talking to a local pedal builder/MOD'er and his first suggestion was to replace the switch.  He told me that a Muff pedal he was working on exhibited the same symptoms and immediately sprang to life when he put in a new 3PDT.  I have checked this switch several times and it appears to be just fine...but I really don't know how to check it any more than to determine whether there is full continuity between one set of adjacent lugs and zero infinite resistance between the opposite set in one switch postion and vice versa.  Is there anything else that would indicate the switch has issues?

[debrad]

Came home and found the details on Q11...the text reads "KSP 13 -H47"

Also checked the potentiometers and found that while they appear to be functioning properly, there may be issues with the "Mix" control and my newly added "Volume".  Here is what I found:

Intensity Control...B50K pot (replacement for stock Danelectro B50K pot)
                          Fully counterclockwise...Lug 1->Lug 2 = 0
                                                             Lug 1->Lug 3 = 54.3k
                                                             Lug 2->Lug 3 = 54.3k
                          Fully clockwise...Lug 1->Lug 2 = 54.2k
                                                  Lug 1->Lug 3 = 54.2k
                                                  Lug 2->Lug 3 = 0

Speed Control...C50K pot (replacement for stock Danelectro C50K pot)
                          Fully counterclockwise...Lug 1->Lug 2 = 0
                                                             Lug 1->Lug 3 = 46.1k
                                                             Lug 2->Lug 3 = 46.1k
                          Fully clockwise...Lug 1->Lug 2 = 46.2k
                                                  Lug 1->Lug 3 = 46.2k
                                                  Lug 2->Lug 3 = 0

Here is where it gets interesting (...although maybe it makes sense given my symptoms and/or the voltages I'm seeing...)

Mix Control...B50K pot (replacement for stock Danelectro B50K pot)
                          Fully counterclockwise...Lug 1->Lug 2 = 0
                                                             Lug 1->Lug 3 = 24.8k
                                                             Lug 2->Lug 3 = 24.8k
                          Fully clockwise...Lug 1->Lug 2 = 24.8k
                                                  Lug 1->Lug 3 = 24.8k
                                                  Lug 2->Lug 3 = 0

Volume/Level Control...A100K pot (newly added by me)
                          Fully counterclockwise...Lug 1->Lug 2 = 0
                                                             Lug 1->Lug 3 = 50.3k
                                                             Lug 2->Lug 3 = 50.3k
                          Fully clockwise...Lug 1->Lug 2 = 50.3k
                                                  Lug 1->Lug 3 = 50.3k
                                                  Lug 2->Lug 3 = 0

Can I assume that I should be reading ~50k on the Mix Control and ~100k on the Volume/Level Control (unless something else in the circuit is SUPPOSED to be influencing those values...).

- brad -

[duck_arse]

if you go to and gaze upon this circuit:
http://4.bp.blogspot.com/-5J3L9R1_Chk/T_WXTQl5NqI/AAAAAAAABo0/K70MXGGHHVE/s1600/fv_sch_vint.gif

and then head over to geofex and look at the technology of article (I'm assuming you haven't yet), you will be able to pick up lots of stuff about parts and placements and what will be interacting with what. most of the original seems to be there in some form. see if you can pick the phase-stage transistor pairs.

the Q11 part # is for an ordinary darlington, it is doing the lamp driving. switches are simple beasts, on or off. as long as all three are on at the time they are meant to be, and versi-visa, the switch is ok. and when you've got those 2 pots off the board, you can check across the board connections to answer that question.

[debrad]

Duck_Arse...I actually DID look at the Univibe schematic and the GeoFex article earlier this week (surprise, surprise).

I did glean some information from them at the time (although probably not as much as I did while reading them again right now) but I wasn't sure how to translate the higher voltages in the "Technology of..." article to what I'm seeing with this Cool Cat (for example, RG mentions a 15V supply...).  I also noticed that there didn't seem to be a 1:1 correlation of parts between that schematic and the Cool Cat layout (i.e. my Cool Cat appears to stop at Q11 while the Uni-Vibe schematic shows Q13) and my lack of knowledge/familiarity leaves me struggling to figuring out which parts are what...and where (I'm sure I just need to take some and sit down with the schematic and PCB in front of me...).   Finally, I don't really understand where the "LFO B+" comes from (the fact that it is labelled as "LFO B+" and not just "B+" like the other sections of the schematic tell me that it has a different source than the DC jack...).

Having measured all the components above...and having re-read RG's article, I can't help but wonder if my problems revolve around Q11 in some way.  RG's article says that Q11 controls voltage to the LFO bulb and if it cancels light to all the LDR's, "the signal goes almost entirely through the phasing capacitors and no phasing is audible"...exactly what appears to be happening in my case!

It would seem to me that I have to find out why Q11 isn't receiving any voltage....is IC2 suspect because every pin measured 0V...are C11 and C28 suspect based on how they reacted with IC1 and IC2...are C26, C29 and C30 suspect because they have 0 voltage on both poles...are C32 and C33 suspect because they had "-" voltages...are my Mix and Volume control suspect because they measure 50% of their rating; unfortunately, I don't really know how to answer any of those questions but I suspect your advice is still to return to stock configuration and go from there...

[duck_arse]

arr, well. no, the parts don't correlate, but the basic blocks will. I think Q11/12 matches your Q11. you've measured the bulb good, yes?

I think the original used 15V because of the bulb limitations. the drop to 9V shouldn't case more than a few resistor values to change, probably.

the IC2 voltage lacks is baffling, and bad. perhaps another measure? I'm pretty sure one of the opamps is an lfo, the other may well be buffering in and out. surface mount markings means I can't be sure of what your IC3 is, but a voltage reg would be one guess. it should have more volts one end and less the other. derr. but what it is supplying is unknown.

and the opamps pin8's would logically be tied together, to the supply voltage. and bypass caps will also be tied between V+ and ground. so those caps you got full volts on would be bypasses, but the opamps have gone awry. maybe probe around IC2 with the continuity range to see where and what it connects to.

and if you look at a transistor datasheet, lets say the BC847, you'll see the smd pinout. knowing where the base and emitters are, you can find the phaseing pairs, Q4/5, Q6/7 etc. then you can follow all the resistors attached, follow the ldr connections, build a picture of what matches the original circuit diagram.

[debrad]

Just a quick note to let you know that I haven't given up on this project ('cause I'm sure you've all been sitting on pins and needles waiting for an update...ha ha ha).  I followed Duck_Arse's advice and *TRIED* to trace my way through a comparison between the Dano Vibe and the original Univibe schematic but I didn't make much progress.

Fortunately, the pedal builder I mentioned earlier has kindly agreed to investigate my work when he finishes up another project he's working on.  I am hopeful that there's a simple mistake or that I just have to replace a component (or two).

In the meantime, I'm happy to report that Danelectro recently shipped me a replacement bulb which I originally thought might have been the problem.  I seem to measure conductivity between the two legs of the original though so I think I'm OK there...

Anyway, thanks again to everyone for all your help so far; I really appreciate it!

Hoping to get started on a BSIAB kit from GGG and a vero Rat plan while I wait for word on the Vibe (fingers crossed that they go a little more smoothly than this rehouse!).

- brad -

[debrad]

At the risk of annoying folks with a necro-thread post, I just wanted to bring some closure to this one.  Unfortunately, the local fellow who offered to help troubleshoot my Cool Cat Vibe rehouse project fell off the face of the earth so I've spent the last 4 years (wow...where did the time go?) looking for a good deal on a replacement

A few weeks ago, a buddy kindly donated a Cool Cat Vibe and I am very happy to report that I just put the final touches on a fully functional rehouse with the delay and volume mods last night!

Given my experience with this round, I have a pretty strong feeling that I messed up the wiring on the LED/Bulb portion of the circuit and that, if I had wired it back closer to stock rather than giving it to my neighbour, I may very well have gotten the original project up and running too...sigh!

Anyway, what doesn't kill us makes us stronger, right?!?!?

Here's the final product in all of its glory!







Thanks for all your help and support in getting this done.

- brad -

[GGBB]

Looks incredible - love that graphic! If Dan-o had done those, they could have charged more and probably sold more.

(Now why haven't I re-boxed mine?!)