TBX Mid-boost kit question

rlw

I already have vintage noiseless pickups and fancy going the whole EC on my Strat so the TBX and mid-boost seems like the way to go.

Question.  I already have an S1 switch on the volume pot.  Can this still be incorporated into the TBX kit?

ICBM

The problem is that the volume pot value is different - 50K in the Clapton circuit, 250K for the S1. It will still work, but the taper might be less than ideal. You could parallel the pot with a resistor to simulate a 50K load, which might improve it. The S1 has enough poles (4) that you could use one to take the resistor back out of the circuit when you’re bypassing the boost - which I assume is the idea.

Funkfingers

The Fender "Clapton" mid booster system consists of a low impedance pot and a PCB slightly larger than a credit card. The latter requires its own routed cavity. Fender positions this under the pickguard. The PP3 goes into an extension of the vibrato spring cavity.

Similar - if not better - results can be achieved via the EMG-SPC mid boost accessory. This consists of a pot with a PCB attached. It occupies less space than a modern CTS push-pull pot. The PP3 fits in the control cavity.

As for the TBX, I would not bother. Reconfigure your upper tone pot to act as Master Treble roll off. Remove the lower tone pot to make room for the EMG-SPC.

I need to scratch my head now to remember how to integrate the active -SPC into the otherwise passive circuit.

If you can find one, it might be more interesting to use an EMG-VMC. This booster allows the centre frequency to be dialled in.

rlw

ICBM said:

The problem is that the volume pot value is different - 50K in the Clapton circuit, 250K for the S1. It will still work, but the taper might be less than ideal. You could parallel the pot with a resistor to simulate a 50K load, which might improve it. The S1 has enough poles (4) that you could use one to take the resistor back out of the circuit when you’re bypassing the boost - which I assume is the idea.

Really, the only idea was that it would be nice to have the neck pickup available in positions 1 and 2, so neck and bridge, and neck, middle and bridge together.

Funkfingers

rlw said:

the only idea was that it would be nice to have the neck pickup available in positions 1 and 2, so neck and bridge, and neck, middle and bridge together.

That is the current circuit in Fender American Deluxe and Ultra SSS Stratocasters. I cannot imagine why it should use all four poles of the S-1 switch for the seven sounds mod.

ICBM

Funkfingers said:

That is the current circuit in Fender American Deluxe and Ultra SSS Stratocasters. I cannot imagine why it should use all four poles of the S-1 switch for the seven sounds mod.

So that when one, two or even three of them have broken, the circuit still works .

rlw

Maybe I won't bother after all.

Funkfingers

It is possible to add mid boost externally. Several Fretboarders profess to using Graphic EQ pedals. Seymour Duncan offers the Pickup Booster pedal - intended to make single coils sound more like humbuckers. In the Eighties, BOSS and Ibanez/Maxon produced semi-parametric pedals. 

ICBM

rlw said:

Maybe I won't bother after all.

If you’ve got the S1 anyway it’s probably worth using it - the pot section never seems to cause trouble, and if the switch is just turning on the neck pickup then even a complete failure will still leave the guitar usable with the normal five sounds. The problem with it is when it’s used for ridiculously complex series/parallel-type switching schemes where a failure leaves you with no sound in at least some selector positions.

I genuinely would wire all four poles in parallel though - that eliminates almost any possibility of failure other than the switch mechanism becoming non-latching, which is its other most common problem.

Forgot to add, you need a 62K resistor in parallel with the 250K S1 pot to simulate the 50K Clapton circuit value.

rlw

Thanks for all the input. It’s much appreciated. I shall leave it for the moment but will try turning up louder and adding a bit more boost from elsewhere.