[Simon Langley]

Curious about the apparent unusual operation of the tone control on my 1969 Gibson Eb-0. When turned from 10 down to 1 the tone gets progressively thinner and the output decreases. It seems that instead of rolling off highs it rolls off lows and volume. Not sure if this is normal or not seeing as how boomy and muddy these basses normally are. The other thing that has me thinking that this is normal is that the difference is very similar to what the "baritone" switch on my 1966 EB-2 does to the tone when activated. Anyone know if this is normal operation or do I have a problem? Have included pictures of the control cavity to show how it is wired up. As far as I know the controls and electronics are OE.



Some strange looking units. Capacitors? Resistors? Inductors?

[eb2]

Your wiring has been altered. That is not OE, but I am not sure what those things are. I am guessing some sort of choke, using the tone pot to bleed the signal through whatever those are. The work was done in a nice clean way, and with some silicone or epoxy to hold them in place to the can. I am curious if someone knows what is going on, electronically speaking.

[jules]

Very interesting. Looks like someone wanted a way of getting a more trebley sound without putting in a bridge pickup. Completely reversible of course. What is the 'thinned' sound like? useable? Not much need for the tone control on an EB0 - most players find the neck humbucker with tone on 10 to be bassy enough.

[Repairman77]

Yes they would be chokes; probably added to get rid of some of the lower frequencies.
Anything like this that's been added would effect the volume, and certainly would not have been original; however I have heard of this mod and I believe there was a thread somewhere on this board discussing it in the recent past.
Mike (Retired Electronics Eng).