Preamp Wiring Diagrams and Schematics

Diagrams for NEW Surface Mount (Epoxy box) Preamps:

2b-4a – Volume (PP active/passive), Volume,  Treble, Bass

2b-4b – Volume (PP active/passive), Blend,  Treble, Bass

2b-4c – Volume (PP active/passive), Blend,  Treble, Bass

2b-3a – Volume (PP active/passive), Treble, Bass

2b-3b – Volume (PP active/passive), Blend,  Treble/Bass Stack


2b-MM - Volume - Treble - Bass


2b+4a – Volume (PP active/passive), Volume,  Treble, Bass

2b+4b – Volume (PP active/passive), Blend,  Treble, Bass

2b+4c – Volume (PP active/passive), Blend,  Treble, Bass

2b+3a – Volume (PP active/passive), Treble, Bass

2b+3b – Volume (PP active/passive), Blend,  Treble/Bass Stack


3b-3 –  Volume (PP active/passive), Mid (PP frequency select), Treble/Bass Stack

3b-4a – Volume/Volume Stack, Tone (PP active/passive), Mid (PP frequency select), Treble/Bass Stack

3b-4b  – Volume/Tone Stack, Blend, Mid (PP frequency select), Treble/Bass Stack

3b-5a – Volume (PP active/passive), Blend, Treble, Mid (PP frequency select), Bass

3b-5b – Volume (PP active/passive), Blend, Tone,  Mid (PP frequency select), Treble/Bass Stack


General Diagrams

Blend Pots! This diagram explains how a blend pot works and how to make sure you have yours wired correctly, because they do not all work the same…


Diagrams for older version of Preamps (Pre-June 2015):

Basic 3B Basic module with pots

Kitchen Sink 3B installation. This shows the preamp with all the bells and whistles including an active passive push pull on the volume and 2 mid frequencies on a push pull. It also has the chart of the mid frequency capacitors and shows how to set up any 2 frequencies you may want on the switch. We do not sell the preamp prewired in this manner, but for those who want to have all the options we offer this diagram.

3B-4a 3 band bass preamp with volume/volume stack, tone(pull passive), mid(pull frequency switch), and treble/bass stack

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

VBT-3B-a – VolumePP, Blend, Tone, Treble, MidPP, Bass

VBT-3B – Volume, Blend, Tone, Treble, MidPP, Bass

VBT-3B-ab – VolumePP, Blend, Tone, Treble, Mid, Bass

VBT-3B-ab_midchart– VolumePP, Blend, Tone, Treble, MidPP, Bass (includes mid frequency selection chart.

3B-4b – Volume/Tone Stack, Blend, Treble, MidPP, Bass

3B-5a – VolumePP, Blend, Treble, MidPP, Bass


Subscribe to Nordstrand News