Tone control works more like volume control

[hoops]

No, this isn't one of those "volume control works like tone control" threads about missing bleed capacitors, I'm having the opposite problem in that dialing down the tone control doesn't affect the tone much, it acts more like a second volume control.

I have a '72 standard Tele that has a Fender humbucker in the neck position and consequently has 1 meg pots for volume and tone (the mod was done by a previous owner). For many years I actually disconnected the tone pot altogether as I didn't have a need for it, but I recently reconnected it.

When I first put back the original green .047 tone cap I noticed this behavior i.e. tone control just affects the volume. I then discovered that the bleed cap was actually .01mf, not .001, so I removed it, but that made no difference. In fact turning down the volume pot now affects the tone much more than changing the tone pot. If I want less volume but NOT have the tone change I can turn down the tone pot. I picked up an Orange Drop .001 bleed cap that I plan to put back in when I sort out the tone control, but for now there's no bleed cap.

I tried replacing the old green tone cap with a Sprague PIO .047 but it's still doing the same thing. It's a really standard wiring, and it's exactly the same as in my '69 Mustang, except for the switches, and the Mustang pots are CTS 250k. Also the Mustang has a .01 tone cap as it has Kinman Strat pickups (I tried a bunch of different values and I liked the .01 best for what I use the Mustang for).

Could it be something to do with having 1 meg pots instead of 250k? As I said, it's a really standard wiring,e.g. http://www.manchesterguitartech.co.u...electrics.html

[originalmatthew]

The last time that happened to me I scratched my head for a couple days. Checked and re-checked my wiring, connections, etc. finally dawned on me to change out the pot, and bingo! Seems the pot was shunting too much signal to ground because it had gotten too hot while soldering on it, and it was burned up.

[tazzboy]

Did you make sure that follow the connection correctly and ground the pots as well?

[tdowns]

Does the volume go all the way to zero at max counterclockwise on the tone knob?

[hoops]

Well I did what I should have done in the first place and ran a multimeter across it, but it all looks OK.

No, it doesn't go to zero volume when the tone is turned all the way down, which I guess would indicate that something is shorted to ground. And the tone pot is NOT grounded, I don't think it should be because that would put it in parallel with the volume pot. The tone cap goes from the middle lug of the tone pot to ground.

I thought maybe there was something screwy about the wiring of the switch, which was a 5-way, so I replaced it with a new 3-way. What I notice now is that for the neck humbucker the tone control is actually working even though it lowers the volume significantly. But for the single-coil neck pickup the tone control actually makes it thinner (and softer) when you turn it down. As I said, turning down the volume control actually rolls off the tops because I removed the bleed cap.

I'll do some more research on having a humbucker and single-coil together, I'm sure you can't just wire them as if they were the same. I realise that having a 1 meg pot will make the single-coil very bright, but so long as I can counter that with a working tone control I don't really mind (and I've been living with it for years anyway).

[tazzboy]

You need to ground your pots other wise you will continue to have the same problem.

[mgwhit]

If you really want help with wiring around here, you need to post pictures. Speculation can only go so far, and and extra pairs of eyes can frequently catch something that you might be totally overlooking.

[hoops]

Well I got sick of trying to figure it out so I ripped everything out and started again with new CTS 500K pots and a new 5-way switch.

The main reason I even started messing around is that I was concerned at the high level of ice-pick trebles I was getting because of the 1 Meg pots. The first thing I tried was the Fat Tele trick of putting a (1 Meg) resistor in parallel with the SC bridge PU, which made me realise that rolling off tops with the tone control is not really the same as what happens when the pot value is changed, because the pot value actually changes the whole resonance of the circuit, while the tone cap simply shunts some of the top end to ground.

What I settled on was using a 5-way switch with the following combinations:

1 - bridge SC
2 - bridge SC + neck HB
3 - HB
4 - bridge SC with 500k resistor in parallel (i.e. 250k equivalent) + neck HB
5 - bridge SC with 500k resistor in parallel (i.e. 250k equivalent)

So position 5 (normally neck PU) neck PU) is now a "standard" tele SC bridge PU into 250K, and position 5 (normally bridge PU) is the bridge SC PU into the full 500k pot.

I'm really happy with it, it gives the best of both worlds - a "normal" Tele and an extra-bright one. What is surprising is that positions 2 and 4 (bridge + neck) are noticably different, the nature of the mids changes even more than the highs.

I'm sure I'm probably not the first to do this, but I haven't found any other threads about this configuration. Anyone else tried this?