# PedalPCB Electrovibe Mini



## fig (Apr 30, 2022)

What a sweet pedal! A really fun build with no hiccups. I used Adafruit low-profile feather headers. Perfect fit! The LDRs are matched and BIAS is set to ear. It's a quiet pedal, which given the effect, it _has_ to be. I had several ideas for graphics but none made the enclosure (meh). The vibe is strong and full, as is the phase mode. All controls are full sweep and _mostly_ useable (subjective).
The 3PDT switch board ended up below the main board and pin headers made the connection nice and neat!



















Build one!


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## jubal81 (Apr 30, 2022)

Sausage and beans. Yum.
What LDRs did you use? Haven't gotten around to mine and I need to do it.


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## Harry Klippton (Apr 30, 2022)

Pink led, those r o u n d caps, uhhhh 🥵🥵🥵🥵🥵🥵🥵🥵


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## fig (Apr 30, 2022)

jubal81 said:


> Sausage and beans. Yum.
> What LDRs did you use? Haven't gotten around to mine and I need to do it.


7532s. I've got another set matched up. I'll send them to you


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## jeffwhitfield (Apr 30, 2022)

Nice build! I aligned my LDR’s to point at my bulb. Is it recommended to point them more up like yours? Also, how did you match the LDR’s?


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## fig (Apr 30, 2022)

thewintersoldier said:


> Great build, but come on Tim, I've done two graphics tutorials and there are no excuses for blank enclosures 🤦🤣


Yeah...it was going to be a dripping big pink battery-operated device but grey-matter works too.


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## fig (Apr 30, 2022)

jeffwhitfield said:


> Nice build! I aligned my LDR’s to point at my bulb. Is it recommended to point them more up like yours? Also, how did you match the LDR’s?


Thanks Jeff. I have no idea, but it works well so 1 out of 1 Figs recommend it 🤪 I measured & matched light/dark resistances and TTD (time to drop) using my internal frequency counter .


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## giovanni (Apr 30, 2022)

I love the grey on grey! Nice work!


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## peccary (Apr 30, 2022)




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## blackhatboojum (Apr 30, 2022)

Those tantalums…. I suddenly have a craving for orange tic tacs


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## andare (May 1, 2022)

All I have is a TC1 component tester and a simple DMM so I suppose I can't match LDRs. Is matching them necessary?


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## fig (May 1, 2022)

andare said:


> All I have is a TC1 component tester and a simple DMM so I suppose I can't match LDRs. Is matching them necessary?


It's my understanding that no _real_ matching is required. I used an LCR45 but a DMM works fine and it's _horseshoe rules_ matching. Testing and measuring components is one thing I do to hopefully avoid a gig in the TS section. It's also my way of learning a bit more about how each component functions within a circuit (my original goal with building pedals...how am I doing so far?).

Here's the datasheet for Siliconex LDRs;



I confess that I did not allow the cells to adapt to 30-50ftc for 16 hours prior to taking measurements, although they were enjoying the glow of my maglight for awhile while I was on break 

Vactrols (optocouplers) are another story....more on that as it becomes relevant.

Questions? Answers? I'll take either!


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## andare (May 1, 2022)

fig said:


> It's my understanding that no _real_ matching is required. I used an LCR45 but a DMM works fine and it's _horseshoe rules_ matching. Testing and measuring components is one thing I do to hopefully avoid a gig in the TS section. It's also my way of learning a bit more about how each component functions within a circuit (my original goal with building pedals...how am I doing so far?).
> 
> Here's the datasheet for Siliconex LDRs;View attachment 25817
> 
> ...


So you measure their resistance under a light and then in the dark and choose LDRs with similar Ohm readings?


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## fig (May 1, 2022)

andare said:


> So you measure their resistance under a light and then in the dark and choose LDRs with similar Ohm readings?


Yep, that's basically it. If they are within datasheet tolerances and close with all three measurements, I call them matched. As with anything, the larger the sampling the closer you can get the matches (for circuits that are picky).


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## temol (May 1, 2022)

Any experience with GL-55xx series ldrs?


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## fig (May 1, 2022)

temol said:


> Any experience with GL-55xx series ldrs?
> 
> View attachment 25829


I have little experience period, but 10 lux is about one footcandle so the 7532 is around 10KΩ @ 10 Lux correct? That would not align with the dark resistance of about 6.8MΩ would it? I'm not sure if that is factored into the circuit or not....


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## giovanni (May 1, 2022)

I think this same question came up on a thread I started about the Duophase and iirc the 55 series should work? I looked at the data sheets the other day and did some math. Check out that thread.


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## Big Monk (May 1, 2022)

I believe I have 8 or so of the Digikey 9203 units slated for my modified EV Mini. 

I think my big boy used the SBE/Jameco units. 

I may look for something cheaper and more plentiful for the Monk Vibe. 

Great build Tim!


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## Fingolfen (May 1, 2022)

I've got a couple of Univibe boards I need to work on... now I'm inspired to actually get cracking...


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## music6000 (May 1, 2022)

thewintersoldier said:


> Great build, but come on Tim, I've done two graphics tutorials and there are no excuses for blank enclosures 🤦🤣


Just For You :


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## fig (May 1, 2022)

That looks grea......

Zoinks! I forgot it has a faceplate 🤦‍♂️ I'll go find it...duh Fig.


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## fig (May 1, 2022)

There now.....hmm, I might actually like it better plain


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## Harry Klippton (May 1, 2022)

fig said:


> There now.....hmm, I might actually like it better plain


The faceplate takes away from the impact of the enclosure color and knob combo


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## Bricksnbeatles (May 1, 2022)

thewintersoldier said:


> Great build, but come on Tim, I've done two graphics tutorials and there are no excuses for blank enclosures 🤦🤣


There are graphics actually. It’s just a really nice subdued 29.9% grey on 30% grey backdrop. A different take on the now played-out black-on-black color scheme. 😉


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## Mentaltossflycoon (May 1, 2022)

It's like, how much more grey could this be? And the answer is none. None more grey.


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## Feral Feline (May 1, 2022)

If you don't like it with the faceplate, you can have a contest for it! 😹


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## cooder (May 2, 2022)

Spiffin' build Tim!
Where d you source mentioned 7532 LDRs?
Component placement and Tanatlum straightness is a meditation in OCDness. Noice.


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## JamieJ (May 2, 2022)

Lovely stuff @fig - I always love your attention to detail.


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## temol (May 2, 2022)

giovanni said:


> Check out that thread.



I'll have to try them out. I have GL-5528, 5537-1, 5537-2, 5549. 
Btw - quite challenging pedal to set up. So many variables - bulb, ldr, two trimmers.


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## fig (May 2, 2022)

temol said:


> I'll have to try them out. I have GL-5528, 5537-1, 5537-2, 5549.
> Btw - quite challenging pedal to set up. So many variables - bulb, ldr, two trimmers.


It wasn't a difficult build. There were a few considerations such as the capacitor package height and the connection headers, but it seems a very forgiving circuit otherwise (or I'm just lucky). It functioned really well on the first test, without any adjustments to trimmers, etc. I would wager as long as the LDRs are within range (dark/light resistance) it would still sound just fine.


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## fig (May 2, 2022)

cooder said:


> Spiffin' build Tim!
> Where d you source mentioned 7532 LDRs?
> Component placement and Tanatlum straightness is a meditation in OCDness. Noice.


Thank you sir!
I've bought them from a few sources, but these are solid.








						Photocell Silonex/Advanced Photonix NSL-7532
					

Small Bear Electronics DIY Parts




					smallbear-electronics.mybigcommerce.com
				



I have some of these lamps from SB as well, but I used an older one without the base. I fashioned my own using an LED bezel insert.


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## Paradox916 (May 2, 2022)

outstanding!  Love your mojo build aesthetic.


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## temol (May 2, 2022)

fig said:


> It wasn't a difficult build.



I find Univibe easy to build. In my opinion it just requires additional effort to find the right parts. It's like with fuzzes with germanium transistors. One step to the right and it's magic, one step to the left..  nothing special


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