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?

 

[steviejr92]

It looks like r24 and r26 are the same value? R24 should be 4k7 and r26 should be 47k possible mixup? Can’t tell though.

 

[Tpruitt]

Yep. R26 is 4k7.
But that is in the bias circuit. How would that effect my output volume?

 

[Tpruitt]

I just looked over every resistor and r26 is the only one I see wrong.
The volume drop when engaged is huge.
Should I go back to the original on r4. I have it at 2m original is 47k. R4 mod is unity volume mod.

 

[steviejr92]

@Big Monk Just listing his name here. Hes much better suited to help answer that question!

 

[Big Monk]

I just looked over every resistor and r26 is the only one I see wrong.
The volume drop when engaged is huge.
Should I go back to the original on r4. I have it at 2m original is 47k. R4 mod is unity volume mod.

Something else is amiss. R4 at 2M should be increasing things above unity gain.

Can you post pictures of the u see side of the board?

Don’t go crazy pulling stuff out and replacing. This is the time during troubleshooting when most people use thier soldering iron like an implement of Conan the Barbarian style revenge.

Hang tight while we try and figure this out.

You also say the effect is weak. How so? Is there any phasing at all?

 

[Tpruitt]

No phasing. I guess maybe the effect is weak because the output is so weak.
Ok I’ll pull it apart and take pics of the other side. It’ll probably be tomorrow.

 

[Tpruitt]

It is a tight fit. I don’t know if I’ll ever get it back in the case again lol.

 

[Big Monk]

It is a tight fit. I don’t know if I’ll ever get it back in the case again lol.

Do you have the speed pots insulated?

 

[Tpruitt]

I just had tape behind them.

 

[Robert]

It's almost always the dual pots, and usually when there is tape behind them.

It might not be in this case, but it's worth a look.

 

[steviejr92]

I just had tape behind them.

If you have those pot covers you can take your cutters and cut out the extra material so it can fit your dual gang pots. might not look the prettiest but it protects your pots from short circuiting the board.

 

[Tpruitt]

That was it. I still need to change that one resistor and tune the bull in to taste.
I appreciate the help and ideas guys.

 

[Tpruitt]

Here is my luck. Put it back in the case with dust covers. Tune the bulb. Put the cover on and call it good and the dang bulb sticks up to high now. Back to taking it apart again.

 

[andare]

Here is my luck. Put it back in the case with dust covers. Tune the bulb. Put the cover on and call it good and the dang bulb sticks up to high now. Back to taking it apart again.

I guess that's why a 1590BBS has been recommended.
I just built a FF in one of those, with the jacks over the pots and I can't imagine using a shallower enclosure.

 

[Tpruitt]

Lol. Yeah the dust caps made it stick out just enough the back won’t go on.

 

[Big Monk]

Lol. Yeah the dust caps made it stick out just enough the back won’t go on.

This is a common issue. I would order the 1590BB2/BBS.

 

[fig]

Lol. Yeah the dust caps made it stick out just enough the back won’t go on.

If they are the harder translucent covers, I always cut them down to just enough sidewall to stay on the pot. Otherwise, there is a ~2mm airspace left between the bottom of the pot and the bottom of the cover. That 2mm can make a huge difference sometimes.

 

[Robert]

I should have the thin (1mm) pot insulators within the week.

These along with squeezing down the tabs on the dual pots will get it into a standard depth 1590BB.

 

[The Gator]

I used a thin piece of blister pack type packaging plastic with a tiny dab of glue and stuck it underneath the double pots.
About .015" thick.
Also, I put a round head end mill bit in the drill press and drilled a small divet in the backplate where the lamp hits. Doesn't take much. A 135° tip .375" drill bit would work nicely as well.