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fender3x
19-01-2019, 09:27 AM
I have never put a treble bleed into a bass. I don't think I have seen one either. I have read about a "G&L" treble bleed (a 200pF cap with no resistor), but my G&L ASAT bass didn't have one. I haven't seen one on a Jazz or Precision either. Which raises a question for me about whether you need a treble bleed on a bass? It occurred to me that there may not be that much treble to bleed off in the first place. Curious what the experience of others has been?

wazkelly
19-01-2019, 12:27 PM
Yeah, i have added treble bleed on my EX5 but only works if a switch is used. Doesn't w oirk with j bass setup

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Simon Barden
27-01-2019, 10:45 PM
It's partly going to depend on how many pickups you have and whether you end up using the volume pots.

On single pickup basses like a straight Precision, then you can easily fit one. But if you always have the volume on full, then you don't need one; there won't be any benefit as both sides of the bleed cap+resistor are then sitting at the same potential as the pickup output.

With dual pickups, then you can have several scenarios with passive circuits.

1) Gibson style wiring with a selector switch. You can have a treble bleed on both volume controls. The standard wiring here means that with the switch in the 'both on' position, having one volume up and the other turned down very low or set to zero effectively connects the output of the other pickup to ground as well, giving no or little output. This effect far outweighs any other effect that a treble bleed might have, so fitting treble bleeds to the volume pots doesn't have any noticeable effect on volume levels, but will keep the tone brighter at reduced volumes.

This might be of benefit to you in single pickup mode, but in dual pickup mode with some slight volume reduction on one pickup, you may not get quite the same sound as before, especially if turning the bridge pickup down to try and get a more bassy mix, but the bleed keeps the treble content up. It's worth experimenting with, and only takes a couple of snips to remove if you don't like the effect.

2) Standard J-bass or P+J wiring with two volume and one tone knob (as Waz mentioned). The volume pot wiring is different to the 'Gibson' method as there is no selector switch, so the pots are wired differently to allow one volume to be turned to zero without affecting the output of the other pickup. But here, fitting a treble bleed circuit to the volume pots allows all but the lowest frequencies from both pickups to be sent to ground when one volume is at, or near zero volume, which means that it basically only works with both volumes at or near full and takes all the normal pickup blending options away. So treble bleed in this wiring configuration is a very BAD IDEA.

3) J or P+J wiring with a blend, volume and tone pot. A treble bleed pot can be happily used with this type of circuit as the blend pot effectively isolates the pickups whilst the volume pot behaves just like it would in a single pickup circuit.

fender3x
31-01-2019, 07:04 PM
Thanks, Simon. That really helps. I am thinking about doing the Gibson wiring.

This bass has two pups. Both Bill Lawrence humbuckers. One in the P Bass Position. The other in about the EB-0 position.

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fender3x
31-01-2019, 07:07 PM
... not sure how I'll use the pickups yet. Bit of an odd configuration dictated by where the body already had routs as much as anything...

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