Capacitor on blend knob

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AussieRick
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Capacitor on blend knob

Post by AussieRick »

I just had my ‘99 360/12 open to check some wiring and clean the pots. i noticed that my blend knob 5th knob) has a capacitor running between the two outside lugs of the pot. It's a different type to the tone caps, but looks to be the same value. I've not seen this cap on any schematic, and disconnecting it didn't really have much effect. I've had this guitar for 20 years, but pretty sure I didn't install it.

Any ideas?
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jps
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Re: Capacitor on blend knob

Post by jps »

AussieRick wrote: Thu Sep 26, 2024 9:29 pm I just had my ‘99 360/12 open to check some wiring and clean the pots. i noticed that my blend knob 5th knob) has a capacitor running between the two outside lugs of the pot. It's a different type to the tone caps, but looks to be the same value. I've not seen this cap on any schematic, and disconnecting it didn't really have much effect. I've had this guitar for 20 years, but pretty sure I didn't install it.

Any ideas?
It was modded prior to your ownership. I have no idea what that mod is supposed to do.
AussieRick
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Re: Capacitor on blend knob

Post by AussieRick »

I thought as much. i've removed it.
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jps
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Re: Capacitor on blend knob

Post by jps »

AussieRick wrote: Fri Sep 27, 2024 1:44 am I thought as much. i've removed it.
Have you noticed a change in sound with the cap's removal, and if so, what was it?
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Re: Capacitor on blend knob

Post by AussieRick »

Seems the same to me.
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kennyhowes
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Re: Capacitor on blend knob

Post by kennyhowes »

Of all the wacky mods that people do with blend knobs, that's a new one to me. Maybe it was to brighten up the neck pickup or something.
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Blomp
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Re: Capacitor on blend knob

Post by Blomp »

kennyhowes wrote: Fri Sep 27, 2024 6:51 am Of all the wacky mods that people do with blend knobs, that's a new one to me. Maybe it was to brighten up the neck pickup or something.
Yep, that's exactly it - I thought it was a fairly common mod. I think this mod is mostly recommended by people who are so used to having a modern 'balanced' pickup set with an overwound bridge pickup that the contrast between the equally spec'd bridge and neck pickup on a rickenbacker is just too much for them to handle :lol:

basically as you increase the blend knob the overall volume gets decreased but the bright treble frequencies remain at full volume, giving a little more perceived clarity in the neck pickup tone at a setting where its output level is more balanced against the bridge pickup. In some ways I can see the use of this mod, but also I love the way the stock wiring works in the middle position and don't want to change it!

EDIT: I've just noticed the cap was bridged between the two outer tabs on the blend pot... I don't think this would even do anything at all (unless I'm misunderstanding how the 5th knob is wired up), which would explain why removing it hasn't made any difference. It seems the intention may have been to do what I described above, but maybe it was wired up incorrectly! :lol:
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jps
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Re: Capacitor on blend knob

Post by jps »

Blomp wrote: Sat Sep 28, 2024 7:01 pmEDIT: I've just noticed the cap was bridged between the two outer tabs on the blend pot... I don't think this would even do anything at all (unless I'm misunderstanding how the 5th knob is wired up), which would explain why removing it hasn't made any difference. It seems the intention may have been to do what I described above, but maybe it was wired up incorrectly! :lol:
This is why Kenny and I think this is weird mod.

The fifth knob is really just a second volume control in series with the main volume control, but with the third lug on it disconnected it essentially becomes an attenuator and can't fully turn off the neck pickup on its own. Putting that cap between the two out lugs makes no sense whatsoever, to me, anyway (that third lug doesn't go anywhere).
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