BECOS FX Micro Booster MK4 Onboard Guitar Preamp with Push-Push Switch-Pot, 250K (for Single Coil)

The Micro Booster MK4 Onboard Guitar Preamp takes the magnetic pickup’s signal and delivers a controllable boost that can push a guitar amplifier into solo mode on-the-fly. An integrated two-bands EQ performs soft tonal correction and lets you use it as a Clean Flat Boost, Mid Boost, Treble Boost, Boosted V-Cut, etc.

The BECOS Micro Booster MK4 Onboard Guitar Preamp can be installed in any guitar or bass to boost the signal from passive magnetic pickups. It can be powered with one 9V standard alkaline battery or two batteries connected in series for 18V increased headroom. The booster is powered as soon as the instrument cable TS mono plug is inserted into the instrument output. With very low power consumption, the booster can run for months.

Built with monolithic amplifiers employing bipolar technology with innovative high-performance concepts for pristine audio, the Micro Booster MK4 has an exceptional frequency response and extremely low noise & distortion. This is an exact replica of the preamp section designed for our CompIQ TWAIN dual-band compressor.

The Micro Booster MK4 integrates a Baxandall correction stack which adds flexibility for independent tonal tweaking of Lows and Highs – frequency pivot centered around 720Hz. With mild adjustability of +/-9dB at 70Hz and 2.5KHz before the 0-16dB variable general Gain, it can be configured as a Clean Flat Boost or Mid Boost, Treble Boost, Lows Boost, Boosted V-Cut, etc. without going into extremes. With tone knobs centered, the boost is completely flat.

The Micro Booster MK4 can be optionally configured with a linear B500K switch-pot (used with humbuckers) or with a linear B250K switch-pot (used with single coils) which can be soldered directly on the circuit board. The potentiometer side of the switch-pot is not part of the booster’s circuit, it only replaces a potentiometer in your instrument (volume or tone) while adding the convenience of a signal routing switch on top of it. The mechanical PUSH-PUSH switch side of the switch-pot routes the signal through the booster (switch UP) or sends it True Bypassed straight to the output (switch DOWN).

A grounded iron shielding-can covers the entire active circuitry to protect against RFI/EMI interference.

The basic interconnecting wires, battery holder, battery clip, and a new TRS output connector are supplied along with the uBST4 board and the Push-Push switch-pot.

Several shortcut points are added on the circuit board to eliminate the usage of some wires when reconnecting the replaced potentiometer. Insertion points are also available for a neat transfer of the guitar Tone Capacitor directly on the booster’s board. The Micro Booster MK4 is pin-compatible with MK3.