Low noise & Low Power Onboard Buffer/Booster

Axtivator is an onboard, very low noise and low power buffer/booster for passive guitars. It effectively turns them into active instruments. It uses a modern, high performance Texas Instruments operational amplifier that only entered volume production in 2023.

Axtivator can operate in several modes that can be selected by jumpers or a switch:

1. flat buffer (unity gain)
2. low cut buffer
3. flat booster (same as 1, but with trimmable gain)
4. treble booster (same as 2, but with trimmable gain)

Axtivator must be installed onboard. It replaces the typical 250k or 500k volume pot found on passive guitars with its own actively buffered, low value volume pot (10k). This configuration achieves the lowest possible noise (hiss) at all positions of the guitar's volume pot and completely eliminates any "tone suck" when dimming the volume. The guitar will have exactly the same tone at any volume setting, even when using with very long cables.

Working prototype


Operating Modes unity gain buffer or booster, flat or treble emphasis
Input impedance 1MΩ
Output impedance 1
Supply voltage typ. 9V (5V to 18V)
Current draw 0.22mA
Battery life (alkaline) 2000 hours
Noise floor -115dBu (@ unity gain, 20kHz BW, unweighted)
Max input level +10dBu (@ unity gain)
Dynamic range 125dB  (unweighted)
THD 0.0006%  (@ input=1 dB below max)
Board size 29x18mm
Potentiometer long life conductive plastic, sealed