Electrovibe

[Tpruitt]

My vibe engaged really cuts the volume down. The fx is also pretty week and it’s hard to hear.
Mods
R4 two 1m in series =2m
R12 two 10m in parallel =5m
R14/15 =2k7

I also had to use a 200k trim and not the 250k in the bias spot.

Anything obvious?

 

[Tpruitt]

I used dust covers and I ended up machining the bottoms and using a few washers. Works great.

I have another issue. The output volume is way low. Unfortunately I can’t figure out to to upload a video

 

[Tpruitt]

https://imgur.com/a/mCJCQBu

I’m running this in my boss es8. In front of the amp. Volume maxed. The very first thing.
In the loop is even less volume.

 

[Big Monk]

https://imgur.com/a/mCJCQBu

I’m running this in my boss es8. In front of the amp. Volume maxed. The very first thing.
In the loop is even less volume.

Did you do the unity gain mod?

 

[Tpruitt]

Yes. R4 I used two 1m in series for =2m
The mod thread calls for 2m2

 

[Tpruitt]

Any other ideas

 

[Big Monk]

Any other ideas

Have you done a component to component check to make sure all caps and resistors are the right value?

It’s not uncommon for people to mistakenly put the wrong value somewhere. It definitely seems like you have some signal limiting happening somewhere because the unity gain mod should give you at least a little bit of boosting capability.

I know it’s tedious but print the refdes out and go component to component and check their values.

 

[Tpruitt]

I did that with the resistors when I had one wrong. I’ll go over the caps next.

 

[Tpruitt]

All my caps are right. All the resistors I checked last week.
Only thing I can do is take it apart to double check the volume pot is correct.
Maybe play it out of the enclosure.

 

[Big Monk]

When you change speeds, is the low volume constant across both controls?

 

[Tpruitt]

Yes. The volume never changes other than with the volume knob.
I took it apart and didn’t see anything that stuck out. Volume pots right. Nothing can touch the board. Triple checked the modded resistors.
I may just remove r4 and try that. Remove any signal to ground there.

 

[Big Monk]

Yes. The volume never changes other than with the volume knob.
I took it apart and didn’t see anything that stuck out. Volume pots right. Nothing can touch the board. Triple checked the modded resistors.
I may just remove r4 and try that. Remove any signal to ground there.

And you are sure you put 1M resistors in series for R4?

 

[Tpruitt]

Took them out and measured. 2m.
Played the pedal with them out and no difference in volume.the pcb was out of the box also and I made sure it wasn’t laying on anything conducive.
Looked over the board again and no crossed solder spots. I’m at a loss

 

[Big Monk]

Took them out and measured. 2m.
Played the pedal with them out and no difference in volume.the pcb was out of the box also and I made sure it wasn’t laying on anything conducive.
Looked over the board again and no crossed solder spots. I’m at a loss

So you removed R4 and no change? I would look there.

Did you try soldering in a single resistor into R4? How do the R4 pads look?

Also check in an around the volume pot, including the mixer resistors, etc.

 

[Tpruitt]

R4 bleeds off some signal. Connected at the input it shouldn’t be a huge difference.
So today I printed out the pcb and went over every component one by one. All correct.
Flipped it over and reflowed every solder joint checking to make sure they weren’t touching another part. All good. No marks or cut or anything abnormal on the board.

Took out the volume pot and checked it.
Read 82k. Thought I’d try a 100k resistor across the pads. No change.
Checked my off board wiring. No stands floating off to touch something. Solder good.
At this point I’m thinking it’s a bad component. And it won’t be in the power section. Or even the bulb section.
Since I’m do this as a hobby I don’t have the equipment to figure out what component.