Fender Volume/Tone pedal tone control not working

[Rob A Thomas]

Hello all,
Looking for some guidance on a Fender Volume/Tone pedal issue. I purchased for cheap on EBay knowing it was untested. The volume works great but the tone (boo-ahh) sound doesn’t work. I checked the wiring with schematics here and on the greater inter-webs. It was all wired properly. I checked all the values of the pots to make sure they were within tolerance. I retired the whole dang thing but can’t seem to make the tone knob work. I switched the tone and volume knob thinking one might be dead but both worked in the volume spot.

Any thoughts or recommendations would be greatly appreciated
Rob

[Rob A Thomas]

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[Mike Auman]

According to these posts, the cap should go to your white-wired lug on the volume pot (lug 3), not the yellow-wired lug (2). I would also resolder the other end of that cap on the tone pot, the joint looks a little sketchy.
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[Rob A Thomas]

You are right. I was trying different options for the circuit and adjusted it to match my ‘51 Dual Pro wiring. I moved and re-soldered the cap. Still no joy. Not sure what is going on. Plugging into the pedal totally negates my tone control on the guitar so it is doing something. Just not what it is supposed to do.

[George Biner]

Do you have a link to the schematic?

1. measure both pots, both end to end and wiper to end and make sure they are working
2. working from the original schematic, verify with an ohmmeter that each connection is made (checking at the actual terminals of the components to make sure no bad solder joints) -- your changes to the wiring might be wrong?
3. maybe the cap is bad? capacitance meter, change cap, ??

[Dave Meis]

I have a vintage Fender tone/volume pedal, and if I use any device that changes the impedance (Freeloader, powered pedal, Lil Izzy..), the tone function doesn’t work.
Not sure if this applies to your situation.. just my experience.

[Rob A Thomas]

Do you have a link to the schematic?

1. measure both pots, both end to end and wiper to end and make sure they are working
2. working from the original schematic, verify with an ohmmeter that each connection is made (checking at the actual terminals of the components to make sure no bad solder joints) -- your changes to the wiring might be wrong?
3. maybe the cap is bad? capacitance meter, change cap, ??

1. Measured all components. All are within correct measurements. Pots and cap. Original cap was reading low so swapped for the orange drop in the photo.
2. I used a schematic I found here on the forum that seemed to work for others.

https://images.app.goo.gl/ss93aE14FnmeVbot9

3. The cap was reading low and out of tolerance so I swapped it for the orange drop.

I pulled all the original wiring and replaced with new wiring. Same results. Volume works and sounds great. Tone doesn’t do anything but negates the tone circuit on the guitar.
I am just stumped on this.

[Rob A Thomas]

I have a vintage Fender tone/volume pedal, and if I use any device that changes the impedance (Freeloader, powered pedal, Lil Izzy..), the tone function doesn’t work.
Not sure if this applies to your situation.. just my experience.

I wondered the same as well. So I am just running steel into V/T into amp. And the amp has no tone knobs. Just a 5 watt Epiphone Valve Jr.

[George Biner]

All very mysterious. Need more data.

One thing can do is check the entire path. Put the + of the ohmmeter to the guitar input, and the - to ground. Short the cap, ground the output and check the resistance as you change the two pots -- that will tell you a lot about the circuit. You might let me know the four values you get with the pots at full and minimum.

By the way, what are the pot values? (they are not on the schematic) Is the volume an audio taper type and the tone not?

When you say the guitar tone control is negated, so it just doesn't work at all, no change?

[Tim Whitlock]

I have a vintage Fender tone/volume pedal, and if I use any device that changes the impedance (Freeloader, powered pedal, Lil Izzy..), the tone function doesn’t work.
Not sure if this applies to your situation.. just my experience.

This is my experience as well. I would add that the strings on the Fender VT pedal can slip on the spindle over time, causing the pot to not reach maximum or minimum output. I frequently have to adjust mine. I would set the pedal tone control to full bass and make sure the pot is rotated to the full off position. There is only a small part of the pot range that gives you bass and then the treble comes on quickly as you rotate the control pedal. If the pot can't reach that end of its range you won't perceive any change in tone.