Choke for an EB-3 bass?

[thedarxide]

I'm "renovating" a Columbus copy of a Gibson EB-3 that's been in my loft for 10 years in parts. The original wiring loom has a three way pickup selector, but I'd like to try and add the original wiring options. Does anyone know where I can get a choke for it? I've tried the part numbers and got nothing, I don't know if it's the sort of thing you can just get from maplins or what... otherwise I might just wire a rotary switch for the look but leave off the last position.

[Lfalex v1.1]

It's got to fit in the control cavity, right??

Maplin do ferrite beads for smaller gauges of wiring. Just slide them down the wire and secure it firmly (don't want any annoying rattles!) before you solder it all up.
They should perform the same function as a full-on choke.
Why do you think you might need them? (apart from the schematic suggesting them)
Is the switching likely to be susceptible to RFI?

[Stewart]

I think it's used as a low-cut filter, rather than anything EMI-related...

You could probably knock one up if you knew the inductance value - I'd try looking round this site, and maybe ask on their forum if you can't find the answer:

[url="http://www.gibsonbass.com/"]Gibson Bass site[/url]

[2x18]

I think its a choke thats fitted to the Varitone switch that you are looking for! Just try Googling Varitone and you should come up with some info (Probably in America ) like this.

[url="http://www.guitar-mod.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=V6B&Category_Code=MID"]http://www.guitar-mod.com/Merchant2/mercha...tegory_Code=MID[/url]

Regards

Will.

[johnnylager]

[quote name='2x18' post='176155' date='Apr 14 2008, 11:53 AM'][url="http://www.guitar-mod.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=V6B&Category_Code=MID"]http://www.guitar-mod.com/Merchant2/mercha...tegory_Code=MID[/url][/quote]
And this chap is jolly good too.

[BigRedX]

There are two different versions of the EB3 circuit one with a choke and one without.

This is the [url="http://www.freeinfosociety.com/electronics/schematics/audio/gibsoneb3.pdf?phpMyAdmin=af0f6b4465fe3f904426eaeb3dc0e3fa"]Series 1 circuit without the choke[/url]

This is the [url="http://www.freeinfosociety.com/electronics/schematics/audio/gibsoneb3series2.pdf?phpMyAdmin=af0f6b4465fe3f904426eaeb3dc0e3fa"]Series 2 circuit with the choke[/url] Unfortunately there only appears to be a part number rather than an actual value (choke values are normally measured in Henrys) which may be because the part is custom wound and composed of two coils with a common core rather than just the one.

In fact [url="http://vintageguitars.org.uk/phpBB/viewtopic.php?t=790"]this thread[/url] has more information and from my reading of the discussion it appears that the choke is wound to compliment the pickups so unless your Columbus bass has fairly close copies of the Gibson pickups then the values Gibson used (and from what I've seen of 70s copies getting the pickup covers looking like the originals was as close as they got!) may not be that relevant to you.

If it was me I'd go for the Series 1 wiring...

[billbamberg]

I explored the Varitone at great length for a trashed slot head EBO I restored to an EB3 configuration, but I couldn't find a version worth playing. What little character the EB3 pup has is not to my liking. The EBO is great but doesn't blend well.

It occurred to me the 30K Ohms of the EBO is four times the 7500 Ohms of a Custom Shop 60's JB. By splitting the coils of the EBO, a parallel mix sets both pups to 7500 Ohms. A push-pull switch switches the EBO to parallel or series mix and a second push-pull reverses the polarity of the JB. The Varitone rotary switch allows all mixing possibilities. I made identical mounting plates for the JB and EB3, so the modification doesn't make visible changes to the EB3 configuration. I use the pots on the push-pulls to allow separate tone for each pup

Not only is the tonal range incredible, it mixes two of the most recognized sounds going in some very interesting ways

I 'll send a schematic to anyone interested.

Bill

[airfrank]

On 14/08/2008 at 23:23, billbamberg said:

I explored the Varitone at great length for a trashed slot head EBO I restored to an EB3 configuration, but I couldn't find a version worth playing. What little character the EB3 pup has is not to my liking. The EBO is great but doesn't blend well.

It occurred to me the 30K Ohms of the EBO is four times the 7500 Ohms of a Custom Shop 60's JB. By splitting the coils of the EBO, a parallel mix sets both pups to 7500 Ohms. A push-pull switch switches the EBO to parallel or series mix and a second push-pull reverses the polarity of the JB. The Varitone rotary switch allows all mixing possibilities. I made identical mounting plates for the JB and EB3, so the modification doesn't make visible changes to the EB3 configuration. I use the pots on the push-pulls to allow separate tone for each pup

Not only is the tonal range incredible, it mixes two of the most recognized sounds going in some very interesting ways

I 'll send a schematic to anyone interested.

Bill

Sometime later I realise but if you still have that schematic I'm most interested.

Cheers 

frank