EB-3 wiring

[Psycho Bass Guy]

Years ago I pulled a cap out of a Gibson bass and took it into a guitar shop to get another.  I loved the tone control and figured if they could get me one, I could put it into something else.  They were confused why the bass had an amplifier part in it - it was 400v rating.  Fender used low end disc caps, like you can get at radio shack, but the signal would filter the same and you would never need a high voltage cap.  So, that was probably what Gibson was using - amp parts/bulk buying.

Even those crappy disc caps are rated at 400 and even 600 volts in most cases too. A large electrolytic cap does sound better, especially for bass, but not because the the voltage rating. The cap itself has a lower equivalent series resistance which means it passes more current. That means more low end and an overall fuller sound. It gets better the more expensive the caps become, but like most things with passive components, there is a large point of diminishing returns. Here's a thread that discusses this in more detail (even involves modern era Gibson chicanery):

Magic-Beans

[exiledarchangel]

A large electrolytic cap does sound better, especially for bass

Didn't knew that, I thought electros were a no-no for use in passive tone controls.

[Dave W]

Even those crappy disc caps are rated at 400 and even 600 volts in most cases too. A large electrolytic cap does sound better, especially for bass, but not because the the voltage rating. The cap itself has a lower equivalent series resistance which means it passes more current. That means more low end and an overall fuller sound. It gets better the more expensive the caps become, but like most things with passive components, there is a large point of diminishing returns. Here's a thread that discusses this in more detail (even involves modern era Gibson chicanery):

Magic-Beans

Good thread. I especially liked this comment "I still can't see how Gibson can possible justify the $133 price (and I mean why the 33c?) even if they were identical in every respect to the original ones, hand made, the oil hand squeezed from some rare Peruvian ant and the foil rolled on the thigh of some sultry dusky maiden living on an island in the middle of nowhere."

If Henry reads that, he'll be off to the Peruvian jungles to find some oily ants. And then a Peruvian export official to mislabel the shipment.

[sniper]

Dr. i sent you two pictures to use as reference. call me tonight and i will explain the orientation as i understand it for determining the lug pattern as i don't read schematics either. i think we can get through this.

[drbassman]

Dr. i sent you two pictures to use as reference. call me tonight and i will explain the orientation as i understand it for determining the lug pattern as i don't read schematics either. i think we can get through this.

I'm booked up tonight.  OK if I call you tomorrow during the day?  I'm home from work all day on Wednesday.

[sniper]

anytime

[drbassman]

anytime

Great, thanks!

[eb2]

My update - I am starting to solder up the wiring harness, and have at least the initial lineup set.  Regular EB-3 wiring with choke replaced by schotkey diode black ice do-dad.  Tone pots are push-pull with series parallel for each pup.  Lead pup is SD SM2b minibucker.  Rear is modded mudbucker.  In wiring up for 4 conductor, douche bag me f-ed up one of the coils.  It was a 70s EB mudbucker.  So I replaced one coil with a 60s mudbucker hotter/muddier coil, and the other with a DiMarzio model G coil.  Then I threw an extra magnet in there to fill up the space on the smaller DiMarzio coil.  In series it kicks out 25k.  So, respectable mudbucker oomph, and in theory should sound different with the smaller Dimarzio G coil. I have no idea if this will sound good or bad or what, but I figure it is worth a ride for a bit.  I will let you know when I get it together.

[drbassman]

My update - I am starting to solder up the wiring harness, and have at least the initial lineup set.  Regular EB-3 wiring with choke replaced by schotkey diode black ice do-dad.  Tone pots are push-pull with series parallel for each pup.  Lead pup is SD SM2b minibucker.  Rear is modded mudbucker.  In wiring up for 4 conductor, douche bag me f-ed up one of the coils.  It was a 70s EB mudbucker.  So I replaced one coil with a 60s mudbucker hotter/muddier coil, and the other with a DiMarzio model G coil.  Then I threw an extra magnet in there to fill up the space on the smaller DiMarzio coil.  In series it kicks out 25k.  So, respectable mudbucker oomph, and in theory should sound different with the smaller Dimarzio G coil. I have no idea if this will sound good or bad or what, but I figure it is worth a ride for a bit.  I will let you know when I get it together.

I'd love to hear your thoughts on the sound of the black ice unit.

[eb2]

I will be glad to once I get it all soldered up.  I don't know if I will like it as I seldom like distortion or grind on the bass.  But I find the choke to be not so spectacular, so it is worth a shot.

I am curious on how the mudbucker mod will sound.  Both coils series clock in around 25k, but in parallel the DiMarzio coil sucks the life out of it and drops it down to 5k.  By itself it is over 7k.  Should be peculiar.  If it sucks, I will throw a regular mudbucker from the pile in there.

[eb2]

Ok, guys.  I have some deciphering of the EB-3 wiring to figure out, so I can understand how to modify it in a way that makes sense.  Hopefully I can get it worked out.

What is the purpose of the 220k resistor and the .02mfd cap that I read as being between the mudbucker and the switch.  Is the 220k in there to keep the mudbucker and the lead pup from squelching each other in full volume?  What is the 02mfd cap for? 

I want to make this a sleeper - looks stock, but isn't.  I am going to end up moving things around, as I don't want the stock wiring.  I am not so sure what is the purpose of some of this.

[eb2]

Here is what I am thinking of.  How does it look?

I hope for:
Pos 1 - Mud
Pos 2 - Mud and Bridge
Pos 3 - Bridge
Pos 4 - Mud and Bridge with SChottky diode/black ice on mud

I use push pull tone pots to do series parallel on each pup, so they are using 4 conductors (Duncan color code).  I pitched the 220k resistor, as I think by using a Les Paul Indy vol set up I don't need that, and I skip the 02mfd cap as I dont think I need that with the black ice.

Will this work?

[chromium]

What is the purpose of the 220k resistor and the .02mfd cap that I read as being between the mudbucker and the switch.  Is the 220k in there to keep the mudbucker and the lead pup from squelching each other in full volume?  What is the 02mfd cap for?

That resistor works along with the cap and inductor in the orig circuit to create various filter configs (RLC filters) depending on the position of the varitone switch.  I think the filters end up working like this in the 60s EB-3:

Pos 1:  Mudbucker only with a wide band-rejection filter, letting mostly just the low frequencies thru
Pos 2:  Bridge pickup wide open
Pos 3:  Mudbucker and bridge, with high-pass filter applied to the mud ("choking" the lows out)
Pos 4:  Same as 3, minus the bridge pickup

Anyway, you won't need that 220k resistor if your're ditching the inductor and cap in your new circuit.

If you haven't already bought the Black Ice, you might try picking up some small signal diodes like you mentioned (BAT41s, etc...) and wire a pair of them in parallel - each with opposite polarity - in place of the black ice in your diagram (similar effect for ~$0.40).  Another idea might be to try them in place of the tone control cap for control over the amount of clipping... or even wire one master tone and one clipping pot on the output, instead of a tone control for each pickup.

I still need to wrap my head around your new wiring diagram.  I wasn't understanding the connections on the 3p4t at first glance.  I always have a hard time reading wiring diags, though.  

Cool ideas.  I like the sleeper approach.

[eb2]

If you haven't already bought the Black Ice, you might try picking up some small signal diodes like you mentioned (BAT41s, etc...) and wire a pair of them in parallel - each with opposite polarity - in place of the black ice in your diagram

That is exactly what I did.  I did see a mess up, and I have a correction, which is simple enough.  When you throw the black ice effect in, it is fed into the mix via the tone pot, I believe.  Keeping the cap in there would goof it up a bit, so I have the first three positions of the C lug on the 3P4T for the cap to the mudbucker tone pot, then the 4th position throws the black ice in, and removes the cap.  They stay attached to the ground, but the hot end gets left hanging on the 3P4T when not selected.  That should do it. I am going to solder it up/test it tomorrow when i get a free hour.

[eb2]

An update, and for sh!ts sake, it actually works.  I don't know if there is anything wrong in there yet, but I get all the switch positions doing their thing right.  The black ice schottkey diode thing is actually subtle, and maybe a problem in hearing it is that I am testing it via a headphone amp so it farts in general.  But you can hear a shift in tone and a general grind to it when it kicks in.  I  am using a Duncan SM2B in the mini pup, so it competes very well with the mudbucker, and actually overtakes it with the mud in parallel wiring.  Very happy.