Kepma AcoustiFex® K-11 Tuner, Pickup, Preamp and Effects System

Integrated Chromatic Tuner, Stunning studio-quality effects when unplugged or plugged in, available on select Elite Series guitars…

Real time studio-quality reverb, chorus & delay magic, Integrated chromatic tuner, flexible undersaddle piezo & onboard condenser microphone with level control.

The Kepma AcoustiFex K-11 preamplifier is a marvel of innovation for Acoustic players who desire flexibility in acoustic sound and creative options when playing on stage or acoustically. It was co-developed with X2 DOUBLE, a world leader in innovative pickup designs. The AcoustiFex K-11 System features onboard effects that can be used when both unplugged playing acoustically, or when plugged into an amplifier. This innovative preamp also is designed to enhance and refine your tone when playing “unplugged” or with an amplifier or PA system. It features an integrated tuner that mutes the output jack when engaged for silent tuning, a mic blend control (body), master piezo volume, a tone shaping control plus built-in Reverb, Delay and Chorus effects.

Operation

Unplugged — When playing acoustically, simply press and hold the volume button for 2 seconds to power on the unit. You can adjust the effects coming from the soundhole of the guitar to your taste using the controls on the panel. To power off the unit, simply press the Volume button again and the green LED will go dim. The AcoustiFex K-11 will utilize the guitar body to increase its frequency response and the guitar sound will be more resonant, solid, and dynamic. You can adjust the volume, body & tone controls to suit your tone preferences.

Plugged in — When playing through an amplifier or mixing console, plugging into the output jack will automatically power the unit on and disable the internal transducer to eliminate any feedback.

Tuner — To activate the onboard digital chromatic tuner simply press and hold down the lens of the tuner until it lights up. Doing so will mute the output jack until you power the tuner off again. Note that you can use the tuner independently — the tuner can be turned on even when the effects unit is not active or powered on.

Charging — Instead of burning through 9v and AA batteries at an alarming rate, unstringing your guitar to locate that elusive 9v “pouch” velcro’d in some tone-deadening space, and filling up landfills with dead batteries, Kepma’s AcoustiFex models are powered by rechargeable 18650 mega batteries — the same type of batteries designed for use in Tesla vehicles — that provide you with over 25 hours of playing time on a single charge! The AcoustiFex K-11 comes with a generous 5ft 8in USB to USB-C charging cable to quickly and easily restore power to the system. Simply plug the cable into the charging port on the front of the unit and charge until the light turns green. Expect longer charging times with this battery as you can expect longer playing times with it.

Availability

The AcoustiFex K-11 system is currently available on the Grand Auditorium GA2-232A models and the Mini 36” M2-131A models. You can download the owners guide for the AcoustiFex K-11 unit on the “manuals” page.

Battery Tab

No sound? On SOME AcoustiFex equipped guitars, there is a protective plastic “tab” installed in between the battery and the contact point that prevents the battery from discharging during shipment. This tab needs to be removed before the unit will charge or work when not plugged in.

Simply slack your strings enough to get your hand into the soundhole. The tab is located on the positive end of the battery, or the end that’s closest to the neck of the guitar. Gently pull to release the tab and toss it into the recycle bin.

K-11 Panel Controls:

[BODY] This control is essentially a mic blend control that adds the airiness and “body” of the guitar to the sound, just like placing a microphone in front of the guitar. Turn the knob clockwise, the microphone volume increases; turn it counter-clockwise to reduce the mic mix or pull the microphone sound out of the mix completely. It’s always a good idea to start with the BODY knob completely turned counter-clockwise then slowly blend in the mic and adjust to taste without feedback when plugged into an amp or PA system.

The [BODY] knob is also a phase switch — press down on it to boost bass response at low volumes and increase feedback supression at higher volumes.

[CHROMATIC TUNER] Press the lens of the Chromatic Tuner to turn it on. If you’re plugged into an amp or mixer, the output is muted so your audience doesn’t have to hear you tune up. Press the tuner again to disable it and return to normal playing. There’s a battery level light built into the LCD panel that will light up when your battery starts to get low, indicating you need to charge it.

[VOLUME] Set the Volume rotary as high as possible, without causing distortion. In addition, VOLUME knob is the on/off switch for effects: Press it for 2 seconds: transmission and DSP (Digital Signal Processor) modules are switched on, green light is illuminated. Press it again, transmission and DSP modules are switched off, green light is off.

[REVERB] Reverb selection and intensity adjustment: turn the knob counterclockwise from straight up for ROOM audition mode and amount, and clockwise from straight up for concert HALL mode.

[TONE] When set to “straight up”, the unit is in the default EQ mode and will make your guitar sound fantastic — the sound you expect from your instrument. Rotate the knob counter-clockwise and the tone becomes “softer” with a pronouced midrange — perfect for fingerstyle playing. When turned clockwise, the bass and treble are boosted simultaneously giving a rich balanced yet pronounced response.

[EFFECTS] Here’s where it gets really cool. The Effects knob lets you choose from Chorus or a Delay effect and apply the amount and intensity (or delay speed) turn the knob 50% counterclockwise for CHORUS effect, and turn 50% clockwise for DELAY effect and adjust the amount to your preference.

[USB PORT] The Type C USB port is for charging the battery with the included USB-C cable. Connect the other end of the cable to a standard USB phone or iPad charger and plug into your wall socket. Charging times will vary, but the 18650 Lithium Ion battery is designed to provide longer playing times (up to 25 hours of continuous play), so expect the charging time to be a little longer than your phone.

[POWER LED INDICATOR] A multi-function LED: It turns green when the system is powered on. If you’re charging the battery, it turns yellow until charged, then green when fully charged. It turns red when your battery is almost out of power, so time to charge it up!