John East, best known for his acclaimed J-Retro and U-Retro line of preamps for Fender-style basses, has come up with the Tone Lifter specifically for guitars with Strat-style electronics.
The Tone Lifter is designed to drop into any Strat-style guitar without having to modify the instrument or even having to solder the unit in place. Only a stacked knob is installed where the lower tone control of a Strat would normally be, with the rest of the circuitry being concealed in the guitars control cavity.
The upper knob on the stack controls the gain for a mid-boost or a bass/treble boost, and is active when in the 'up' position.
With the system active, the upper knob's center detent gives a flat frequency response with +2.5dB of gain. This would be the same as your Strat's passive tone, only louder.
Turning the upper knob clockwise from the center detent activates the mid-boost giving 0 - 15dBs of gain. The lower concentric knob now selects the frequency of the mid-boost. Turning the upper knob anti-clockwise gives a variable boost to a bass and treble setting, with the lower knob used to dial in the combined bass and treble frequencies.
The system can also be bypassed for a pure passive signal by means of a custom electronic relay circuit and also bypasses automatically when the battery is low on power.
The Tone Lifter's internal battery is charged by plugging a specialized jack charger adaptor into the guitar's output jack and then plugging it via a connector into an AC mains socket! No more having to remove the pickguard on a Strat to change that 9-volt!
East UK builds every product from a pro audio design perspective -- John East spent a good part of his electronics career in the design teams that created the high-end Solid State Logic (SSL) and Sony Oxford mixing consoles, de facto equipment in nearly every major recording studio.
(Pic Source: www.east-uk.com)