A passive cocked wah sound on a Telecaster

As I posted recently, I had modified my Voodoo Telecaster to add out of phase switching. For the second push/pull pot I had been considering the “Arlo Cocked Wah” modification.

Alfie on the SixStringBliss forum had suggested that using the tone on a Tele can give a good honky sound. Playing around with this I stumbled on something… with the middle selector switch (bridge and neck selected) and the two pickups out of phase, this takes a lot of the bass out of the signal. If I roll down the tone control on the guitar this cuts the top end, leaving just a very honking middle sound – hey presto – cocked wah!

You can hear it for yourself on this brief demo, which covers;

  1. Both pickups in phase, tone turned to max
  2. Both pickups out of phase, tone turned to max
  3. Both pickups out of phase, tone turned to min

Recorded into Reaper using Amplitube’s Orange Tiny Terror model.


Adding out-of-phase switching to a Telecaster

As I posted previously, I’ve added “out of phase” switching to my Voodoo Telecaster and I thought it would be worth sharing the exact details of how I did that.

The Telecaster neck pickup has a very simple construction. There are two leads coming from it. The hot is connected to one end of the coil. The ground is connected to the other end of the coil and the pickup cover.

If you were to just add a switch to invert the phase of the pickup it would mean that the pickup cover would also get switched to be the hot signal and we don’t want that. This means we need to modify the neck pickup slightly. If you look at the underside of the pickup, you’ll see a small jumper wire that connects the cover (lower centre) to one end of the coil and the black ground lead (left).

First we need to break that connection. A simple snip of the wire does it.

Then we need to solder on a separate ground lead. In this case I used a brown wire, just so that when I get to the tangle of wires in the control cavity, I can easily identify it.

Once we get to the control cavity, the brown lead gets soldered to one of the common ground points (I used the back of the volume pot). The two remaining leads from the neck pickup go to the two centre poles of a DPDT switch (double pole, double throw). Like this.

Let’s talk through how this works… If the switch is in the “up” position (the top pair of poles are connected to the centre poles) then one end of the pickup coil (hot) enters at the right side, is connected by the switch to the top right pole and therefore connects to ground. The other end of the pickup coil (labelled ground in this picture) enters at the left, is connected to the top left by the switch and therefore connects to the hot going into the selector switch. Push the switch into the “down” position and the exact opposite is happens. Hey presto phase reversal.

The sound produced is not going to be to everyone’s tastes. It is a very thin twangy sound (think strat position 2 with the bass on your amp turned way down). I love it for reggae/funk style rhythm guitar and it really cuts through a mix well.

Here is a quick test of the four pickup combinations; neck, neck and bridge in phase, bridge, neck and bridge out of phase. In each case it is a simple E major pentatonic running from open low E through three octaves.

Recorded using a Fender Bassman sim on a Line 6 Pod XT Live straight into Reaper.

The Voodoo Telecaster revisited and rewired

While the finish has been drying on my current project, I turned my attention back to the Voodoo Telecaster I built a few months ago. I had never got round to giving it more than a perfunctory setup and nor had I wired in the two push/pull pots that I had fitted. At the time I wasn’t sure what I wanted to do with the switches so had just gone with the standard Tele wiring to start off.

Last night a spent a few hours tweaking the truss rod and action. It has transformed the guitar from something that was OK, into a beautifully playable guitar. Now on to the wiring. I’ve decided that the first push/pull pot will be a phase switch. This will of course only work when the pickup selector is in the middle position. It requires a modification to the neck pickup. As standard, one end of the coil is attached to the pickup cover and then on to the ground lead. I’ll snip this connection and run a separate wire to ground the pickup cover.

The second push/pull is going to be a “turbo” which will switch the volume and tone out of the circuit. A passive volume and tone control will sap somewhere between 8-12db from the pickup signal. Bypassing these passive controls gives a big boost. It is at the expense of having any control (other than the pickup selector switch) but it just sounds great when over-driving the pre-amp stage of my valve amp.

Here’s the schematic I’ve sketched out.

The neck pickup first goes to the phase switch which effectively flips the pickup’s coil round in the circuit. From there it joins up with the bridge pickup at the selector switch. The selector switch goes into the “turbo” switch. When engaged the signal is routed through to the standard Tele master volume/tone controls. When disengaged the output from the selector switch goes directly to the hot of the jack socket.

Edit 1: After completing the rewiring and playing with it for an hour or two I decided to disconnect the “turbo” volume/tone bypass. It just wasn’t working for me. I had previously tried this with humbuckers and P90s and loved it, but with the sharp, cutting single coil pickups it just didn’t sound as I expected. I’m going to investigate the “Arlo Cocked Wah” mod.

Edit 2: I’ve just spotted why the “turbo” mod wasn’t working as I’d hoped. If you trace the scematic through, then you can see, when the turbo mode is engaged, is still allows a path to ground for the hot signal via the vol and tone pots. No wonder I didn’t like the sound, it would have been the same except the volume knob wouldn’t work properly. To correct it I need to use the second poles of the turbo switch to disconnect the vol/tone part of the circuit from the hot. When I get time, I’ll redraw the schematic and retry this mod.