Aguilar 2-BAND OBP BASS PREAMPLES WITH BOOST (STACK TB AND BS)

OBP: Aguilar's Vision of a Simple, Musical, and Ultra-Dynamic Onboard Preamp

The Aguilar OBP-1 is designed for bassists who want to switch to active electronics without "altering" the instrument's voice. Its approach is intentionally streamlined: a 2-band boost-only EQ, designed to enhance what already exists (more fundamentals, more air and definition), rather than extreme sculpting. Within the OBP range, it positions itself as a direct, organic, and effective solution, perfect for adding more body and presence to a passive bass (or modernizing an active bass with an aging preamp).

For Which Bassists and Styles?

The OBP-1 suits both bassists looking for a first "serious" upgrade and seasoned musicians who want reliable electronics with immediate adjustment. The 40 Hz boost adds depth for funk, pop, reggae, and heavy grooves, while the 4 kHz boost restores presence and bite to cut through rock, metal, or fusion mixes.

Live, it's typically the kind of preamp that lets you go from a round tone to a cutting sound without touching the amp. In the studio, its headroom reserve helps maintain a clean and dynamic attack, especially on aggressive playing, slap, or high-output basses. It's also found installed on "signature" instruments, for example on models associated with Flea in active configuration.

Controls, Versions (SK/TK), and Integration into Your Bass

The Aguilar OBP-1 offers two EQ controls: Bass (centered at 40 Hz) and Treble (centered at 4 kHz), with a maximum boost amplitude of 18 dB on each band. The idea is to let you shape the energy in the low end and openness in the high end while maintaining a tone base very close to passive when the EQ is neutral (knobs at minimum).

Ergonomically, you choose the kit best suited to your instrument: OBP-1SK if you want to save space thanks to the stacked potentiometer (single hole), or OBP-1TK if you prefer two separate pots, faster to adjust on the fly. The OBP-1 is wired with an output jack that switches power: when you insert a 6.35mm Jack, the electronics are powered (classic principle of active basses).

Sound Signature

The OBP-1's signature is a wide and musical sounding boost. The 40 Hz low end enhances the sense of "body" and note solidity, ideal for thickening a thin bass or adding authority to fingerstyle playing. The 4 kHz treble boost highlights attack, snap, and harmonic clarity: perfect for restoring bite to a neck pickup, clarifying a pick line, or making slap stand out without making the sound harsh.

Thanks to its all-FET circuit and high headroom, the dynamics remain very responsive: the OBP-1 follows your right hand, handles transients, and keeps an "instrument" feel rather than a "gadget" feel. At 18V, you gain even more headroom before saturation, a real plus with powerful pickups or very aggressive attack.

Technical specifications

Category	bass preamp	EQ	2 channels
Technology	all-Fet

Maximum boost	18 dB	OBP-1TK	separate Treble and Bass potentiometers
Low boost frequency	40 Hz	OBP-1SK	stacked Treble/Bass potentiometer
High boost frequency	4 kHz	Power supply	9V or 18V (via 1 x 9V battery or 2 x 9V batteries)
Output impedance	600 ohms	Consumption	approximately 1.1 mA at 9V (commonly measured value)