Weird cap placement and wiring suggestions

[Lenny JG]

So im currently looking to add a passive/active switch to an old SE3 Artec pre amp and put it in my Ibanez. I was also looking to add a capacitor for the treble pot. When I ripped off the back cavity to the ibanez. THIS is what I saw.

A big green capacitor going from the back of my treble pot going to the switch in a weird way? Also the switch is just kinda there? Is this switch acting as a capacitor switch?

My second thing I wanted to ask is this: If I wanted that cap to shunt treble and also have a passive/active would I wire it like this?

 

[SharpCat]

Um, more pics please? Possibly a drawing of where the wires are currently going? I can't make out from the one picture.

In the second drawing, where are the black wires shown on the back of the switch connected? Ground?

 

[Lenny JG]

Um, more pics please? Possibly a drawing of where the wires are currently going? I can't make out from the one picture.

In the second drawing, where are the black wires shown on the back of the switch connected? Ground?

There is one wire going from lead 5, to my jack, and then there is a capacitor running through leads 1 and 3 and then soldered to the back of my treble pot. 2 and 4 may be connected, but I can't tell totally, even when I get close. I think more pics will not help you at all with this but if you insist I will.

The diagram i posted, the black wire leading from 1 to 6 is just a wire going from 1 to 6. The black wire on 5 is going to ground, it would be a standard bypass wiring, my concern is more or less with the rest of the diagram and how the switch adds in.

 

[Lenny JG]

Um, more pics please? Possibly a drawing of where the wires are currently going? I can't make out from the one picture.

In the second drawing, where are the black wires shown on the back of the switch connected? Ground?

Okay finally got the time to do this, so for the 1st picture, im trying to figure out the function of this cap. When I flip the switch, I think it does..... something? I haven't analyzed the frequencies. I feel like maybe someone was trying to make a switch to change the voicing of the circuit? Or maybe they didnt know how to wire a passive/active? Maybe its an older wiring that im unaware of? It's a rats nest in this bass lol.

The green arrow indicates the cap, the green dots indicate the points where the cap is connected. The white dots indicate the two legs connected to eachother by a wire, and to no other points. The pink lines indicate where there is a wire attaching switch and jack. The last leg of the switch is not attached to anything.

Now the 2nd pic is an Artec SE3 that I had someone rip out of a bass for me a few years ago. The connections aren't clip based like the newer versions of this pre, meaning im doing some guess work as to what went where since somebody butchered the connections. Mostly I'm trying to figure out what point on pcb the volume ground would've been connected to? It had 3 wires, so I assume one was ground for some reason? Or maybe the volume needs all 3 wires for some reason? From pics i find online i cant quite tell tbh, but i think blue goes on bottom? Idk though because it seems that the orientation of the pots in accordance to the diagram would indicate the opposite? Lol

Here I'll show the diagram from Artec and the Diagram I made for a possible active/passive install, and possibly an added cap to shunt treble to ground.

Here, the yellow is the orange wire leading from the middle leg of the volume knob to top left switch post, while the middle left switch post leads back to normal volume path. Top right post of switch leads to out (red). Middle right switch post goes to ring on jack (gray), bottom left switch post to ground. There is a wire connecting top left and bottom right switch posts (black). The cap is the green bar, I would connect it to the middle treble lead and then to the back of the volume pot.

 

[SharpCat]

OK, here's what I think so far. (Boy, do I miss @fig !)

Current wiring:
When the switch is DOWN, the center and top contacts of each side of the switch are connected. So basically nothing, since they've got wires connecting them already on each side. Maybe something else was in there before and is now gone.
When the switch is UP, the center and lower contacts are connected, so the red wire I think is the preamp out to the jack is tied to the full cap value to ground with no pot. That's essentially tone on full.

So seems to me to be a tone on/off. Does it sound like that?

Your suggested mod:
I don't think that's going to work. For one thing, the pot values are wrong--they're 100K for bass/treble and I think 50K for volume? Those are pot values for the pre to interpret, not pot values to directly modify the signal like a passive circuit. I see what you're doing with the switch, and the right half makes sense (assuming you are disconnecting the direct jack connection at the bottom of the diagram), but the left half pumping the pre out into the volume pot doesn't make sense to me.

Here's my suggestion--Go the Darkglass route, and blow off treble adjust. Get a tiny 100K trim pot->
Can order them from the big A (where I grabbed that pic) and lots of places, cheap. Solder that in place of the treble pot wires on the board, and in the treble pot spot, wire in a normal tone control pot connected to the pre out. You can open the back of the bass and set the treble wherever sounds good and just leave it there. You can wire the switch or just have the tone control always available.

Anyway, that's my best guess.

 

[Lenny JG]

OK, here's what I think so far. (Boy, do I miss @fig !)

Current wiring:
When the switch is DOWN, the center and top contacts of each side of the switch are connected. So basically nothing, since they've got wires connecting them already on each side. Maybe something else was in there before and is now gone.
When the switch is UP, the center and lower contacts are connected, so the red wire I think is the preamp out to the jack is tied to the full cap value to ground with no pot. That's essentially tone on full.

So seems to me to be a tone on/off. Does it sound like that?

Your suggested mod:
I don't think that's going to work. For one thing, the pot values are wrong--they're 100K for bass/treble and I think 50K for volume? Those are pot values for the pre to interpret, not pot values to directly modify the signal like a passive circuit. I see what you're doing with the switch, and the right half makes sense (assuming you are disconnecting the direct jack connection at the bottom of the diagram), but the left half pumping the pre out into the volume pot doesn't make sense to me.

Here's my suggestion--Go the Darkglass route, and blow off treble adjust. Get a tiny 100K trim pot->View attachment 7086771
Can order them from the big A (where I grabbed that pic) and lots of places, cheap. Solder that in place of the treble pot wires on the board, and in the treble pot spot, wire in a normal tone control pot connected to the pre out. You can open the back of the bass and set the treble wherever sounds good and just leave it there. You can wire the switch or just have the tone control always available.

Anyway, that's my best guess.

It had an 'Ibanez EQB-IIIS 3-band EQ and mid-frequency toggle' from what I can read.

At some point it stopped working, and nobody i knew could figure it out, so I just had them throw in this cheap Amazon pre. Was it possibly the mid toggle? I feel like it was wired different before. The switch doesn't seem like tone full on, but I could be wrong.
I'm basing my wiring for the switch off of two things.
This wiring for the darkglass tone capsule, the pcb connections at top from left to right are: in, ground, battery+, and out.

And this diagram found in another thread about active/passive switching.

So if I change pot values, would I be able to accomplish this?
And I know a trim pot is cheap, but I'm trying to do this w/ stuff I already have atm. Maybe in the future though I will try that also for another bass if not this one.

 

[SharpCat]

Yeah, those diagrams make sense to me. But in the darkglass setup, the volume and blend are passive, before the preamp, and the preamp is single-input. So they keep working fine when the pre is switched out of the signal path. With the artec, the balance/blend looks like it's passive, and the two wires from it are probably signal and ground. But the volume is part of the preamp circuit, not separate and passive. I don't think you can just change the pot values. That'd make the pre not work right IMHO.

Now, you could pull the volume out of it's hole, set it to full, and tape it so it doesn't move. (or swap in a trim pot.) Wire in a passive volume like in the darkglass diagram. That'd work, but you're still without a tone control. (And you'd have to somehow fit an extra pot in the back of the cavity.)

That seems to be the real issue--you're short a control spot to put a tone control. You could get double-stack pots. Fat Bass Tone has a 50K/250k that you could replace the volume and also have a tone. You'd also need stacked knobs.

So here's the choices I see:

1. Passive blend, with or without double-stack volume/tone.
Use the blend as "Input" on the switch. Run that to the tone control (assuming you do the double stack thing) and also to the switch. The Effect Send goes to where the blend connects now, the OUT connection on the artec board is "Effect Return". Wire the other half of the double pot to the volume wires on the artec. With all that, you can go passive, but volume will be always full on in passive.

2. Make it more like the darkglass.
Use a pot inside the cavity to force the artec into full volume, but wire in a passive volume before the preamp. (basically the diagram above.) Optionally, get a double-stack 250K/250K to add both passive volume and tone. Feed those into the switch.

3. Stay active.
Yank the ineffectual switch and call it a day.

4. Find some other preamp that does what you want.
Downside: $$$

5. Just go passive.
Easy, Cheap. Can reuse the existing blend knob.

I'd probably do 4 or 5. You do you, though.