# Univibe issue - bulb not bright / deep enough flashing.



## nznat (Sep 20, 2022)

Im having trouble with a vibe build.  Here's the thing. When i plug in the power supply, i see the bulb go brighter and deeper in the flashing mode, seems perfect, yet after about 1 second after i plug in the power supply it suddenly goes more dim, the depth of the flashing has gone much dimmer / less, thus the lush univibe tone is mostly gone because of this, doesn't sound correct anymore. Any ideas on power supply issues on the pcb or what part of the univibe circuit controls the power of the bulb itself? Can anyone point to these areas and caps etc that regulate the bulbs depth of flashing on the schematic attached so i can remedy this situation?
much appreciate your help


----------



## Big Monk (Sep 20, 2022)

nznat said:


> Im having trouble with a vibe build.  Here's the thing. When i plug in the power supply, i see the bulb go brighter and deeper in the flashing mode, seems perfect, yet after about 1 second after i plug in the power supply it suddenly goes more dim, the depth of the flashing has gone much dimmer / less, thus the lush univibe tone is mostly gone because of this, doesn't sound correct anymore. Any ideas on power supply issues on the pcb or what part of the univibe circuit controls the power of the bulb itself? Can anyone point to these areas and caps etc that regulate the bulbs depth of flashing on the schematic attached so i can remedy this situation?
> much appreciate your help



Post pictures, top and bottom, of your
Board. 

Which board is it? Have you double and triple checked all the component values and your solder joints?


----------



## nznat (Sep 20, 2022)

i have made three of the boards, all came out the same, soldering is fine. everything now working fine except bulb depth of flashing. just not deep and bright enough. Or thats what i think. the sound is more like a tremelo effect rather than a swealing lush vibe effect


----------



## music6000 (Sep 20, 2022)

If we a talking dual Vibe, Did you use* L78L12* voltage regulator?


----------



## Big Monk (Sep 20, 2022)

nznat said:


> i have made three of the boards, all came out the same, soldering is fine. everything now working fine except bulb depth of flashing. just not deep and bright enough. Or thats what i think. the sound is more like a tremelo effect rather than a swealing lush vibe effect



You need to give us something to work with. 

Pictures are a start.


----------



## music6000 (Sep 20, 2022)

nznat said:


> i have made three of the boards, all came out the same, soldering is fine. everything now working fine except bulb depth of flashing. just not deep and bright enough. Or thats what i think. the sound is more like a tremelo effect rather than a swealing lush vibe effect


This is standard practice, saves the guessing game:





						Important: Supplying Pictures when an Issue arises with a PCB Build !!!
					

I  have to raise this ongoing issue when Members ask for Help with an Issue with their Build. I keep repeating this saying '' Pictures are worth a Thousand Words'' !!! Please supply Pictures of PCB & ALL connections ( Footswitch, Input & Output Jacks, Power Jack ) to it  along with a clear...




					forum.pedalpcb.com


----------



## nznat (Sep 20, 2022)

music6000 said:


> If we a talking dual Vibe, Did you use* L78L12* voltage regulator?


whats a dual vibe?


----------



## nznat (Sep 20, 2022)

Big Monk said:


> You need to give us something to work with.
> 
> Pictures are a start.


above picture of schematic? board wont show much as you cannot see the tracks


----------



## Big Monk (Sep 20, 2022)

nznat said:


> above picture of schematic? board wont show much as you cannot see the tracks



We only have your word as to the quality of your soldering, general assembly, etc. 

It helps to give us pictures so we can reference the schematic and try to point you in the right direction?

Right now we only know your bulb is acting erratically. 

If we can view your board, determine what the LFO looks like as well as the lamp driver, we can gives you some paths for troubleshooting. 

If you don’t, we are flying blind.


----------



## Big Monk (Sep 20, 2022)

Have you tried adjusting the lamp gain trimpot?


----------



## nznat (Sep 20, 2022)

Just attached my entire schematic. I dont need to send picture of board aswell as the soldering is the best of the best as its a SMD / Surface mount i got made at the factory, the soldering is perfect. The thing with the pedal is that it is working, all functions, but the vibe effect sounds like shit. more so like a bad tremelo, and i almost get there with the mini pot adjustment but it just doesn't get the deep and "swishy" sound. its flat and tremelo.  Ignore the parts that are relay switching, as the pedal has two sets of pots to have dual settings.


----------



## Big Monk (Sep 21, 2022)

Tune with light shield on.


----------



## nznat (Sep 24, 2022)

Big Monk said:


> Tune with light shield on.


haha good one


----------



## Big Monk (Sep 24, 2022)

nznat said:


> haha good one



Seriously though, tune the circuit with the light shield on.


----------



## fig (Sep 24, 2022)

Who designed the board layout?


----------



## nznat (Sep 24, 2022)

fig said:


> Who designed the board layout?


what board layout?


----------



## fig (Sep 24, 2022)

whats on second.


----------



## Robert (Sep 24, 2022)

who?


----------



## fig (Sep 24, 2022)

The guy who designed the board the OP says “sounds like shit”.


----------



## Locrian99 (Sep 24, 2022)

I don’t see a schematic here.   Maybe I missed it.   I know the time I had a similar issue with a vibe sounding like a tremolo my Ldr had too large of a spread.   And the dark resistance was too high.   I solved this by running a resistor in parallel.


----------



## nznat (Sep 20, 2022)

Im having trouble with a vibe build.  Here's the thing. When i plug in the power supply, i see the bulb go brighter and deeper in the flashing mode, seems perfect, yet after about 1 second after i plug in the power supply it suddenly goes more dim, the depth of the flashing has gone much dimmer / less, thus the lush univibe tone is mostly gone because of this, doesn't sound correct anymore. Any ideas on power supply issues on the pcb or what part of the univibe circuit controls the power of the bulb itself? Can anyone point to these areas and caps etc that regulate the bulbs depth of flashing on the schematic attached so i can remedy this situation?
much appreciate your help


----------



## Big Monk (Sep 24, 2022)

Locrian99 said:


> I don’t see a schematic here.   Maybe I missed it.   I know the time I had a similar issue with a vibe sounding like a tremolo my Ldr had too large of a spread.   And the dark resistance was too high.   I solved this by running a resistor in parallel.



Or having an offset trimmer. Which this awesome design doesn’t have.


----------



## Locrian99 (Sep 24, 2022)

Yea I had to add an offset to my the depths from eqd clone because everytime id turn the rate low the lfo would stop o’n.


----------



## Big Monk (Sep 24, 2022)

@nznat

We are just having a little fun with your predicament.

A few questions:

1.) Are you tuning the board with the light shield on?

2.) Which LDRs are you using?

3.) Can you tack in an offset control to the lamp driver circuit?


----------



## nznat (Sep 24, 2022)

fig said:


> whats on second.





fig said:


> The guy who designed the board the OP says “sounds like shit”.


whos the OP?


----------



## nznat (Sep 24, 2022)

Locrian99 said:


> I don’t see a schematic here.   Maybe I missed it.   I know the time I had a similar issue with a vibe sounding like a tremolo my Ldr had too large of a spread.   And the dark resistance was too high.   I solved this by running a resistor in parallel.


what rating on the resister?


----------



## nznat (Sep 24, 2022)

Big Monk said:


> @nznat
> 
> We are just having a little fun with your predicament.
> 
> ...


Tuning with light shield on: YES
My LDR: PGM5659D
I installed an offset adjustment that replaced the 100k / 47k with a 250k pot.


----------



## carlinb17 (Sep 24, 2022)

17


----------



## nznat (Sep 24, 2022)

carlinb17 said:


> 17


17?  resister value in parallel?


----------



## Big Monk (Sep 24, 2022)

nznat said:


> Tuning with light shield on: YES
> My LDR: PGM5659D
> I installed an offset adjustment that replaced the 100k / 47k with a 250k pot.



The light resistance in those LDRs is probably the culprit. 

Data sheet says 150-300k when the generally accepted best sounding units have a range of 5-20k


----------



## carlinb17 (Sep 24, 2022)

nznat said:


> 17?  resister value in parallel?


Sorry erroneous entry… must have been a bot


----------



## fig (Sep 24, 2022)

GL5528 correct Derek?


----------



## Big Monk (Sep 24, 2022)

fig said:


> GL5528 correct Derek?



Light resistance is a good range but Dark resistance is probably too low at 1M


----------



## Locrian99 (Sep 24, 2022)

I used the 5528 with a 330k (which if I remember right out it around 250k) in parallel in my the depths and am very happy with it.   The part # for the abyss I believe has 500k which I’m sure would be fine.


----------



## Locrian99 (Sep 24, 2022)

This circuit may have some different needs though.


----------



## nznat (Sep 24, 2022)

Big Monk said:


> The light resistance in those LDRs is probably the culprit.
> 
> Data sheet says 150-300k when the generally accepted best sounding units have a range of 5-20k


can you show me the proper range. 5-10k doesnt make any sense.  light or dark etc.?  what is the part number for the best vibes?  and what is the best vibe? Hendrix original vibe was dark as anything, the brightness didnt exist until he cranked the amp. these days people keep trying to create a vibe that sounds like a concert volume bright tone, yet in the bedroom, yet thats "nothing" like the real univibe which was NOT bright sounding at all, it was uniform and organic "big and round". everyone is going for the bright, because they are not going to be playing loud.   check this out:


----------



## Locrian99 (Sep 24, 2022)

What we are referring to is the Ldr not the sound.   So your Ldr when hit with a lot of light has a min resistance say 10-20k.   When it’s dark it also has a resistance say 1M.   Yours is have to look again when it’s light has like 200k and dark is 10m.   That is why it sounds like a tremolo it’s not letting any signal through at 10m.   I would try the gl5528 as was suggested it has good stats tayda has one similar stats that is around 500k dark I think.   But in my albeit limited experience you want around 500k dark around 10-20k light.  I’ve only built the one vibe that has 4 ldrs so the stats could be very different for yours.


----------



## Big Monk (Sep 24, 2022)

Locrian99 said:


> I used the 5528 with a 330k (which if I remember right out it around 250k) in parallel in my the depths and am very happy with it.   The part # for the abyss I believe has 500k which I’m sure would be fine.



My only concern with using this anecdote for the Univibe is that the bulb has different on/off and intensity characteristics as the LED in the Abyss.


----------



## Locrian99 (Sep 24, 2022)

I was literally editing as you posted.  Yes it may be very different.


----------



## nznat (Sep 24, 2022)

Locrian99 said:


> What we are referring to is the Ldr not the sound.   So your Ldr when hit with a lot of light has a min resistance say 10-20k.   When it’s dark it also has a resistance say 1M.   Yours is have to look again when it’s light has like 200k and dark is 10m.   That is why it sounds like a tremolo it’s not letting any signal through at 10m.   I would try the gl5528 as was suggested it has good stats tayda has one similar stats that is around 500k dark I think.   But in my albeit limited experience you want around 500k dark around 10-20k light.  I’ve only built the one vibe that has 4 ldrs so the stats could be very different for yours.


great reply, thanks for that input. i have found a GL5528 that is local in my country. ill grab it and try.


----------



## Big Monk (Sep 24, 2022)

nznat said:


> can you show me the proper range. 5-10k doesnt make any sense.  light or dark etc.?  what is the part number for the best vibes?  and what is the best vibe? Hendrix original vibe was dark as anything, the brightness didnt exist until he cranked the amp. these days people keep trying to create a vibe that sounds like a concert volume bright tone, yet in the bedroom, yet thats "nothing" like the real univibe which was NOT bright sounding at all, it was uniform and organic "big and round". everyone is going for the bright, because they are not going to be playing loud.   check this out:



The best LDR I’ve used is the 9203. 

5-20k Light Resistance.

20M Dark Resistance.


----------



## nznat (Sep 20, 2022)

Im having trouble with a vibe build.  Here's the thing. When i plug in the power supply, i see the bulb go brighter and deeper in the flashing mode, seems perfect, yet after about 1 second after i plug in the power supply it suddenly goes more dim, the depth of the flashing has gone much dimmer / less, thus the lush univibe tone is mostly gone because of this, doesn't sound correct anymore. Any ideas on power supply issues on the pcb or what part of the univibe circuit controls the power of the bulb itself? Can anyone point to these areas and caps etc that regulate the bulbs depth of flashing on the schematic attached so i can remedy this situation?
much appreciate your help


----------



## Locrian99 (Sep 24, 2022)

I socketed my Ldr and led and tried several combinations before I settled which is what I would suggest.


----------



## Nic (Sep 24, 2022)

nznat said:


> whos the OP?


OP = Original Poster, or similar...  so it's you


----------



## nznat (Sep 24, 2022)

Big Monk said:


> My only concern with using this anecdote for the Univibe is that the bulb has different on/off and intensity characteristics as the LED in the Abyss.





Big Monk said:


> The best LDR I’ve used is the 9203.
> 
> 5-20k Light Resistance.
> 
> 20M Dark Resistance.


20MEG!!!!  wouldnt that be so low that it would thumb the speaker? someone just stated to use 500K dark. man some different info coming in


----------



## Big Monk (Sep 24, 2022)

nznat said:


> 20MEG!!!!  wouldnt that be so low that it would thumb the speaker? someone just stated to use 500K dark. man some different info coming in thats not helping here as they specs are WAYYYYYY different to each other.



We are talking about two different circuits. The other poster is referencing the EQD Depths. 

We are talking about the Univibe. 

Thump the speaker? I don’t follow.


----------



## nznat (Sep 24, 2022)

Big Monk said:


> We are talking about two different circuits. The other poster is referencing the EQD Depths.
> 
> We are talking about the Univibe.
> 
> Thump the speaker? I don’t follow.


talking about two different circuits? huh? so this isnt about my circuit anymore, just a general conversion about anything at all?  dam


----------



## Big Monk (Sep 24, 2022)

nznat said:


> talking about two different circuits? huh? so this isnt about my circuit anymore, just a general conversion about anything at all?  dam



Try new LDRs. 

Preferably one close to the specs I quoted above. 

The issue now is your light resistance.


----------



## nznat (Sep 24, 2022)

Big Monk said:


> Try new LDRs.
> 
> Preferably one close to the specs I quoted above.
> 
> The issue now is your light resistance.


sorry which specs? so many people tuning in with massively random comments and part specs?   dark and light specs?


----------



## fig (Sep 24, 2022)

Apologies for any confusion. Best of luck.


----------



## nznat (Sep 24, 2022)

fig said:


> Apologies for any confusion. Best of luck.


what do you suggest,


----------



## Big Monk (Sep 24, 2022)

nznat said:


> sorry which specs? so many people tuning in with massively random comments and part specs?   dark and light specs?


----------



## Haz (Oct 14, 2022)

I have pcb together bug get clean sound no vibe effect? Slight lfo hissing in background.
Bulb is flashing and trimmers work, pots appear working. I've tested all 5088 above hfe 600. Tried a different IC. If I install L78L12 oriented as on pcb bulb doesn't flash. Other way around it flashes but not vibe effect.
I suspect maybe wrong photocells?
Any clue where to start?


----------



## Bricksnbeatles (Oct 14, 2022)

You’re not testing it exactly as shown in the picture, are you? The ambient light of the room is a no go. You want to text the circuit in complete darkness- either make a light shield to go around the photocells and bulb; turn off all of the lights and rest in a _totally_ dark room, or (least practically, in case you need to take it out agsin) test it after it’s all boxed up with the lid closed back up.


----------



## Haz (Oct 14, 2022)

Ok I will try this


----------

