2B+ Preamps

Overall gain is 0 to 15db by a trim pot on the circuit board.

Bass +15db @ 50Hz

Treble +15db @4khz

Switchable Treble Response Curve (see chart)

Battery life is estimated to be around 250 hours for an alkaline 9v.

Adding a battery to make it 18v will give more headroom and longer life.

View frequency response curve here

The following represent our current versions of our preamps. If you are looking for different options, please contact the shop. Special requests are welcome:

2B+ - 2 band bass preamp with 2 eq pots.

2B+4a - PREWIRED – 2 band bass preamp with volume (pull passive), volume, bass and treble.

2B+4b - PREWIRED – 2 band bass preamp with volume (pull passive), blend, treble, and bass.

2B+3a - PREWIRED – 2 band bass preamp with volume (pull passive), treble, and bass.

2B+3b - PREWIRED – 2 band bass preamp with volume (pull passive), blend, and treble on bass (stack)

2B+4c - PREWIRED – 2 band bass preamp with volume (pull passive), blend, tone, and treble on bass (stack)

*All prewired preamps include jack and battery terminals

In 2006, Carey’s evil genius produced these preamps’ design with a handful of goals in mind. They have an informative technical history that occurred somewhat close to the following chronology of invention—ordered as such in order to illustrate the electrical debauchery and collage of component regulated frequency inherent to Carey’s creative mind:

1 - First off, using the simplest topology possible, Carey designed the circuit so that it is optimized for low noise, transparency, and musicality.

2 - The eq points were chosen with close attention to established industry standards. We wanted very usable frequencies tailored for the broadest application with sensitive and easily managed controls which allow for precise and easily repeatable adjustments.

3 - Carey felt it was important to have additional gain at hand. For this we include a small trim pot on the unit that allows as much as 15db of gain. Set to 0, this control gives unity gain, which means that with the eq controls set to 0 the input will equal the output. This makes it very easy to match the output level between active and passive settings.

4 - On the two band there is a dip switch which allows two different treble eq points. Standard being 4k while optional is 5.3k.

5 - When first introduced, we wanted to offer these units prewired and you’ll notice that most of the configurations include a passive tone pot. Carey feels this is one of the most useable controls on a bass and even with the active tone controls it's a great thing to have on a bass for quick familiar access to more vintage inspired sounds.