Electrovibe (Big Monk)

Just did a quick side by side between my Electrovibe and my EHX Good Vibes.

Electrovibe did not fare as well as I’d hoped. I still have some tweaking to do but I’m not sure it’s going to stay.

The Speed issue is troubling and also it has less speed available, even on Speed 1, than my Good Vibes.

Here is the comparison based on the 11 “ticks” on the Speed dials. Equivalent medium speed occurs as follows:

Good Vibes: 5
EV Speed 1: 7
EV Speed 2: MAX

The Good Vibes also a ton more fast speed setting in the last quarter of the dial.

I really had high hopes for this one, and it could be builder error or component issues, so I don’t want to give the impression that anything is wrong with the project itself.

Conversely, this could be a testament to HOW good the Good Vibes is.
 
In order to eliminate the possibility I messed up the pots, I ordered 10 more from Tayda. I’ll remove the ones currently installed when they get here and measure them, then measure and match a set to reinstall.

I can’t think of anything else it might be.

Here are two bits of good news for those building or planning to build this:

1.) I subbed the 47k R4 for 100k and it is perceptibly, but barely, just below unity. It is very close. When I swap the pots out, I think I’ll sub in a 220k.

100k is a great starting point and provides a pretty much unity volume level.

2.) The bi-color LED is a success. Simply cut the trace between the top and middle lugs on the Speed foot switch breakout board and:

a.) Solder the second cathode to the top middle lug

b.) Run a wire from the main board. ground pad to the middle middle lug. Leave the ground pad on the breakout board empty.
 
I have 2 questions for the forum members who have built the Electrovibe:

1.) Has anyone else’s experienced the Speed having different maximum speeds?

2.) Did anyone measure and match their Speed pots?

If I can sort out why I’m experiencing variance in maximum speeds, I can modify the 4.7k resistors in the Speed control network to get more maximum speed and do a true comparison to my Good Vibes.
 
The real truth is that the Electro stays true to the original. Which could be construed as a short-coming. There are so many ways of doing things better these days that its really subjective as to what the "perfect" vibe would be. Gain loss - check. Hiss - check. Top end loss - check (depending on how the originals caps are doing).

So I don't think you can do an apples-apples comparison to ANY version of the Vibe (let alone an old original). It captures the "spirit" of the original version in spades. Whether or not that is as good as a newer version is always up for debate and honestly I could take both sides. For my use, this is it. I have a half dozen variants that might to a better or worse job depending on my mood too.

Dang, it's not supposed to be this complicated. Imagine what the Fuzz Face freaks have to deal with :)

I don't notice much speed difference so I'd chalk it up to parts variance. Then again I'd be trying for different speeds anyway so I don't really care if they match each other.

On the plus side...an Electro into a 20w MonkWatt? Bliss bro'
 
The real truth is that the Electro stays true to the original. Which could be construed as a short-coming. There are so many ways of doing things better these days that its really subjective as to what the "perfect" vibe would be. Gain loss - check. Hiss - check. Top end loss - check (depending on how the originals caps are doing).

So I don't think you can do an apples-apples comparison to ANY version of the Vibe (let alone an old original). It captures the "spirit" of the original version in spades. Whether or not that is as good as a newer version is always up for debate and honestly I could take both sides. For my use, this is it. I have a half dozen variants that might to a better or worse job depending on my mood too.

Dang, it's not supposed to be this complicated. Imagine what the Fuzz Face freaks have to deal with :)

I don't notice much speed difference so I'd chalk it up to parts variance. Then again I'd be trying for different speeds anyway so I don't really care if they match each other.

On the plus side...an Electro into a 20w MonkWatt? Bliss bro'

My concern is not it’s originality or even how it stacks up to my Good Vibes. My concern is at maximum, Speed 2 is almost 40% slower than Speed 1.

Just wanted to see if anyone else had that big a variance.

It defInitely has a great sound but if it’s to replace my Good Vibes, I need both Speeds to have the same Range and then tweak them to be a little faster.
 
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The more I’ve studied, the more I’ve learned my issue can only be a damaged pot.

The fastest speed available is obviously full up on the dial and thus corresponds to the pots being shorted (zero resistance).

For a major difference in speed between controls, Speed 2 must have stray resistance when full up.
 
Today I’m going to pull the board and components out and run some checks. I’m confident the switching on the Speed side is good, so I'm certain it’s an issue with the Speed pots.

I’ll have to be careful not to damage the pads getting the old pots out. If I do, I believe I’ll have another go with a fresh board.
 
I GOT IT!

When I was trying to re-seat the Speed controls to get the lamp to clear the inside of the lid, I must have lifted the pad to the middle lug of the top gang on Speed 2.

It basically lost its jumper connection on that gang from wiper to pin 1. I added a manual jumper and speeds are equivalent now.

I may still play with the 4.7k resistors to get more speed but not until I thoroughly test the circuit at volume.
 
Nice work! Another member just kindly reminded me that it is always the weird little issues that give us the biggest headaches.

I am with @Gordo though, it may not be crazy fast and have all the bells and whistles but to me it sounds beautiful and i can channel my inner machine gun.

What would be the perfect univibe though? That is a question I will be thinking about for a while.
 
Nice work! Another member just kindly reminded me that it is always the weird little issues that give us the biggest headaches.

I am with @Gordo though, it may not be crazy fast and have all the bells and whistles but to me it sounds beautiful and i can channel my inner machine gun.

What would be the perfect univibe though? That is a question I will be thinking about for a while.

I’m with you. The tone of the Electrovibe is wonderful. I’m only very slightly going to increase the speed.

The perfect Univibe? I don’t think I’m qualified to answer that but the EHX Good Vibes is very good. Now that I’ve fixed the Electrovibe, I can make a fair comparison.

Hell, I may keep both.
 
Another forum question: Are we running Univibes pre-dirt and even pre-fuzz?

I did both yesterday and generally preferred it before. My Phase 90 as well.
 
Another forum question: Are we running Univibes pre-dirt and even pre-fuzz?

I did both yesterday and generally preferred it before. My Phase 90 as well.
I swing both ways.

Sometimes before sometimes after, I think most of the time it is before
 
In my research, it seems the place to adjust for higher speeds would be the 4.7k resistors (R14/R15) and the 1 uf caps (C7, C8, and C9).
 
2.) The bi-color LED is a success. Simply cut the trace between the top and middle lugs on the Speed foot switch breakout board and:

a.) Solder the second cathode to the top middle lug

b.) Run a wire from the main board. ground pad to the middle middle lug. Leave the ground pad on the breakout board empty.
I just received my PCB and will start procuring the parts. I also want to do the bi-color LED mod so I'm trying to wrap my head around this.

This is what I understand so far:

  1. Use a bi-color LED with common anode and connect the anode and one of the cathodes to the Speed LED pads on the main PCB.
  2. Solder the second cathode to the top middle lug of the Speed breakout board (with the pads facing the main PCB's pads).
  3. The ground pads are those with the interrupted line around them.
  4. I can't see the trace I'm supposed to cut on the breakout board. Do I just make a couple of slashes between the pads with an X-Acto knife?
 
I just received my PCB and will start procuring the parts. I also want to do the bi-color LED mod so I'm trying to wrap my head around this.

This is what I understand so far:

  1. Use a bi-color LED with common anode and connect the anode and one of the cathodes to the Speed LED pads on the main PCB.
  2. Solder the second cathode to the top middle lug of the Speed breakout board (with the pads facing the main PCB's pads).
  3. The ground pads are those with the interrupted line around them.
  4. I can't see the trace I'm supposed to cut on the breakout board. Do I just make a couple of slashes between the pads with an X-Acto knife?

1.) Yes. Since I used a Red/Blue Bi-color, I connected the red to the board and the cathode for the blue to the switch and used a blue Knob for Speed 2.

2.) Yes. Top middle lug with breakout pads aligned.

3.) On the main board, the Speed switch ground is the fourth pad over from the left.

4.) With the Speed switch breakout board holes line up with the main board, flip the board over and there is a trace between the top and middle lugs on the middle pole. I made 2 cuts about 1mm apart and them tested continuity to make sure that did the trick.
 
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