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Topic: Treble Bleed circuit for 50's Fender Dual Pro? |
Jim Newberry
From:
Seattle, Upper Left America
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Posted 19 Mar 2008 1:17 pm |
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Hey Guys,
I've got a Fender D-6 (early 50's, trapezoid pickups) and I lose all treble on the lower part of the volume range. The pickups are pretty hot and I'd like to be able to use them at the lower part of the range so they don't hit the front of the amp too hard.
I'd like to not have to try several values, so does somebody have any experience with these pickups so that they could recommend cap/resistor values to start with? I'm using CTS 250K pots and a .047 tone cap currently.
Thanks,
Jim |
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Brad Sarno
From:
St. Louis, MO USA
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Posted 19 Mar 2008 2:36 pm
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Jim,
it sounds like maybe you have your volume pot wired backwards. The output jack should connect to the wiper (middle leg) of the pot. The pickup signal should be on the opposite connector from the ground lug.
Brad |
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Jim Newberry
From:
Seattle, Upper Left America
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Posted 19 Mar 2008 3:17 pm
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Brad,
I don't think so (I may be wrong...). My main problem is that I gradually lose treble when the volume pot is turned down.
Here is a picture I used:
(This isn't mine, I found it on the web).
along with consulting a wiring diagram I found on John Ely's web site for the Dual Professional. Here's a clip of that:
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J Fletcher
From:
London,Ont,Canada
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Posted 19 Mar 2008 3:44 pm
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| What Brad said. You will get more treble if the white wire from the selector switch goes to the unused lug on the volume control. Leave the white wire that goes from the center lug to the output jack where it is...Jerry |
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Jim Newberry
From:
Seattle, Upper Left America
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Posted 19 Mar 2008 4:11 pm
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Thanks guys. I think that's what John Ely's 2nd version of the diagram says:
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Jim Newberry
From:
Seattle, Upper Left America
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Posted 19 Mar 2008 4:12 pm
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| This could keep me from getting treble blood on my hands. |
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Marvin Born
From:
Ohio, USA
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Posted 19 Mar 2008 8:57 pm Treble bleed
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Regarding the Alt. connection, drawing, when you connect the pick up to the high side of the volume and the center terminal to the output jack; which is the better way to connect it, you now have two pots across the high side to ground. This will give you 125 K ohns,instead of the normal 250K. This could also reduce the highs. I would suggest you remove the wire from the high side of the tone pot, and let the cap go from the center terminal and have ground of the other leg.
If you still want a high freq bleed circuit, add a .001 cap from the high side of the volume control. (the line you just added,) to the center lug. As you turn down the volume control more highs are added via the cap. With volulme control all the way up, the .001 is shorted.
Marvin |
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Brad Sarno
From:
St. Louis, MO USA
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Posted 20 Mar 2008 5:03 am
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Yup,
that second drawing makes better sense to me. That way, reducing volume doesn't reduce the "load" on the pickup. What the pickup sees stays fixed, and the tone control will actually be quite active. Let us know how that tone control works for you. I'm wondering if even that way it might give you too much treble as you reduce the volume if you leave the tone control wide open. You may find that a midway setting on the tone knob gives the most balanced tone as you change volume. I'm curious to hear what you find with that.
The way you had it wired, as you lower the volume, the load on the pickup drops too, and that makes it a treble control as well as a volume control. I had a Rick Bakelite that was wired that way. It was kind of cool, but really didn't allow for much volume control without messing with the treble response of the pickup.
Brad |
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Jim Newberry
From:
Seattle, Upper Left America
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Posted 20 Mar 2008 8:07 am
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Brad,
Thanks, that makes quite a bit of sense. Hopefully, I'll have a chance to do the work this weekend and I'll post my findings. Pree-shee-ate the help!
Jim |
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Jim Newberry
From:
Seattle, Upper Left America
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Posted 20 Mar 2008 9:16 pm
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OK, so this weekend came early. I rewired it according to the second diagram and (with new CTS pots and a fancy-schmancy Mojo tone cap) and that made all the difference. The tone control works much more evenly across the volume range. It is more trebly overall, but I think it's much more like I expect.
Thanks for your help with this. No treble bleed necessary. |
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