Explaining the Aguilar Onboard Bass Preamp

The aguilar brand from New York is well known for its pickups and built-in preamps in addition to Bass amps and effectors. They are often used in expensive Basses, and I get the impression that many professionals use also use them. My favorite Bassist, Francis Rocco Prestia, also loves the astringent LTD Bass with the aguilar active PU system. This time, I would like to introduce the onboard preamplifier for Bass from such the talented aguilar brand.

All current built-in preamplifiers from this brand come with pots! It's easy because you don't have to worry about the resistance value when considering the combination with the preamplifier. The products are roughly divided into (1) OBP-1, (2) OBP-2, and (3) OBP-3. The general features are described below.

① OBP-1

2-band EQ boost only
・Bass / Treble can boost up to 18db each

② OBP-2

2-band EQ boost / cut
・Bass(40Hz)　±18db
・Treble(6.5KHz)　±16db

③ OBP-3

3-band EQ boost / cut
・Bass(40Hz)　±18db
・Mid(400Hz or 800Hz) ±16db
・Treble(6.5KHz)　±16db

In addition to these, TK or SK, PP Kit or Kit are added after each model name. PP Kit: Push/Pull pot (Mid)
Kit: Mini toggle switch (Mid)
TK: 2 pots (Bass and Treble)
SK: Stack pot 2-axis double pot (Bass / Treble)

As mentioned in the series introduction above, Mid can be switched between 400Hz and 800Hz. The 3-band EQ type can be wired so that the frequency band can be switched with the included Push/Pull pot or mini toggle switch. I set it to 400Hz when I want to control the warmth of the tone, and 800Hz when I am aware of sound penetration, which is a little more noticeable. The remaining Bass and Treble can be controlled by two independent pots or the 2-Axis double stack pot.

Even if you install a new built-in preamplifier, you want to avoid having to alter the body of the instrument as much as possible. Passive-Bass activation is difficult due to limited capacity. The aguilar preamplifier has a wide variety of pot combinations, so it saves as much space as possible while creating a wide variety of sounds.

The product lineup is summarized in the table below.

Product name	Feature
	2-band EQ Boost only Pot×2
	2-band EQ Boost only 2-Axis double pot×1
	2-band EQ Boost / Cut Pot×2
	2-band EQ Boost / Cut 2-Axis double pot×1
	3-band EQ Boost / Cut Pot×2 Push/pull pot（Mid）×1
	3-band EQ Boost / Cut Pot×3 Mini toggle switch（Mid）×1
	3-band EQ Boost / Cut 2-Axis double pot×1 Push/pull Pot（Mid）×1
	3-band EQ Boost / Cut 2-Axis double pot×1 Pot（Mid）×1 Mini toggle switch（Mid）×1

As a characteristic of the sound, although this is a personal impression, I feel that the EQ control works well. And the noise level is really low. Even if you don't prepare a separate preamp pedal, you can manage the level. Recommended for those who do not want to carry around a pedal or who are not satisfied with an equalizer with a natural effect.

In addition, there is a wiring diagrams on the manufacturer's site, which is very easy to understand when installing it yourself. Please check them out.

OBP-1
OBP-2
OBP-3