HeadAmp

The HeadAmp is designed to be installed and used onboard a bass guitar. You can plug headphones or in-ear monitors directly into your bass and start playing immediately, anywhere, no amp needed. The 3.5mm Stereo Aux In also lets you play along your favorite tunes or backing tracks.

The HeadAmp turns itself on when headphones are plugged. If the bass has active electronics, it will also power them up at that time. There's no need to plug a guitar cable just to use headphones.

HeadAmp is not just for private practice. You can also use it while playing with your band, to monitor yourself independently of what is happening (or not happening!) in the room or on stage. Hear yourself, always!

Maximizing battery life was a top design priority because nobody likes changing batteries. We managed to achieve an idle current draw as low as 0.6mA – on par with a typical 2-band active bass EQ. We are not aware of any other headphone amp that doesn't draw at least 5 times more idle power.  

HeadAmp works with both active and passive pickups. When used in a passive bass, you'll have to add a 9V battery to provide power. You can even power it with a single CR2032 3V button cell if you have to (output power and battery life will be reduced).

The HeadAmp's potentiometer controls the instrument volume only. To adjust the Aux In level, use the connected device's own volume control.

Specifications (2nd Generation)

Input impedance: 1MΩ (instrument), 10kΩ (Aux In)
Idle current draw: 0.6mA
Battery life (9V alkaline): >800 hours @ idle, less under load (depends on average playback level and headphone impedance)
Supply voltage: 9V alkaline battery (nominal). Minimum 2.7V. 18V not recommended.
Output power (each ch.): 120mW/16Ω, 130mW/32Ω, 90mW/80Ω
Dimensions: 49x25x15mm  (approx. 2x1x0.6")
Max installation depth: 5mm  (3/16"). Supports pickguards, control plates, rear covers, as well as through wood (up to 5mm).
Potentiometer : Ø6mm round shaft, M9x0.75 bushing