Electro vibe mini - with mods!

[Raspymcnasty]

This was my first double decker build and it does not disappoint. I am shocked at the size and sound this pedal pushes.

I did run into a couple of issues with parts. Firstly, the electrolytics were a bit confusing, mouser lists length and height, and you really have to dig into data sheets for accurate information. Secondly, the 2.54 spaced headers recommended on another thread from Tayda were far too tall (I probably purchased the wrong ones). I didn’t want to order and pay shipping so i just made a couple of wires and just hard wired it. In my opinion the headers didn’t have confidence inspiring grip to the pins. I accepted the fact it would have been a giant pain in the butt to troubleshoot, but luckily it worked without a hitch!

I have done a few mods listed below.

R4 - 2M2 - Unity vol mod
R12 - 5M - Slow speed mod
R14/R15 - 2k7 high speed mod
C10/C13/C15/C21/C23/C24/C26 - 10 uF - Low end mod
Q3/Q4 - 2N3904 - Reliability mod
Q14 - MPSA13 - darlington final phase stage mod

All thanks to the thread from Big Monk.

L

 

[Big Monk]

How does it sound?

 

[Raspymcnasty]

How does it sound?

Deeper than the original one i built. It also goes slower. I still want to mess with the trimmers more to dial it in.

I’ll A/B test it when I get some free time.

 

[caspercody]

Thanks for the pictures of your build

 

[Duffman]

Would anybody be as nice to point these out on the mini-board? So far i can only find documentation about the large electrovibe.
Thank you SO MUCH in advance!!

R4 - 2M2 - Unity vol mod
R12 - 5M - Slow speed mod
R14/R15 - 2k7 high speed mod
C10/C13/C15/C21/C23/C24/C26 - 10 uF - Low end mod
Q3/Q4 - 2N3904 - Reliability mod
Q14 - MPSA13 - darlington final phase stage mod

 

[Big Monk]

Would anybody be as nice to point these out on the mini-board? So far i can only find documentation about the large electrovibe.
Thank you SO MUCH in advance!!

R4 - 2M2 - Unity vol mod
R12 - 5M - Slow speed mod

Skip R12. Change C7/C9 to tantalum and change C8 to 2.2u tantalum.

R14/R15 - 2k7 high speed mod

Use 1.2k.

C10/C13/C15/C21/C23/C24/C26 - 10 uF - Low end mod
Q3/Q4 - 2N3904 - Reliability mod
Q14 - MPSA13 - darlington final phase stage mod

Skip all this.

 

[Duffman]

i've done all of the above, i did use 2.7k for R14/R15 because otherwise the lamp would stay on.
However, when the pedal is turned on there seems to be a VERY SMALL OVERDRIVE effect on i'm talking just barely. It doesn't matter what the output volume knob is turned to. Any idea what it could be?

 

[falkry05]

Given the lack of published refdes DWGs, where is "R4 - 2M2 - Unity vol mod"? Your images do not jive with this google cached image of R4.

 

[Robert]

Given the lack of published refdes DWGs, where is "R4 - 2M2 - Unity vol mod"? Your images do not jive with this google cached image of R4.

https://docs.pedalpcb.com/project/EVMini_Audio_RefDes.png

https://docs.pedalpcb.com/project/EVMini_Audio_Schematic.png

https://docs.pedalpcb.com/project/EVMini_LFO_RefDes.png

https://docs.pedalpcb.com/project/EVMini_LFO_Schematic.png

 

[timrobertson100]

If it helps anyone reading, I only had a 1M resistor to hand when I built mine and tried that in R4.
To my ears, full volume on the pedal is now ever-so-slightly louder than when disengaged. I presume with 2M2 you can go louder, but if the goal is unity, then 1M worked out for me.