What bass configurations does the STC-3P work with?

The STC-3P is designed for any bass with two passive pickups and space for a single 9v battery cavity plus four control knobs. The pre-wired harness includes a stereo jack and all necessary components for direct installation.

Can I run this on a single 9v battery, or do I need two?

The STC-3P operates on a single 9v battery out of the box. You can wire two 9v batteries in series if you want additional headroom and extended dynamic range for more demanding live or studio situations.

What controls does the STC-3P include?

The circuit features concentric bass and treble knobs, dedicated mid-range control, master volume, blend control, a proprietary Slap Switch for enhanced articulation, and knurled black dome-style knobs for precise operation.

Is this circuit suitable for beginners or requires electronics knowledge?

The STC-3P is recommended for intermediate, advanced, and professional players. Installation assumes comfort with bass electronics and control cavity work; beginners unfamiliar with soldering and electronics should seek professional installation help.

How does the STC-3P preserve my bass's original tone?

Built around a high-headroom, low-noise design with minimal distortion across the full frequency range, the STC-3P amplifies and shapes your passive signal while maintaining the organic warmth and character of your pickups rather than coloring or overprocessing them.

Do I pay sales tax on this order?

We collect sales tax only on orders shipped to California. Orders shipped to any other US state are charged $0 sales tax at checkout when you buy direct from our website. On this item that is roughly $12 less out the door than the same listed price at a national retailer or on a marketplace. Marketplaces such as eBay, Reverb and Amazon collect sales tax in nearly every state as marketplace facilitators no matter who the seller is, so the same item at the same price costs less bought direct. Free US shipping and 30-day returns are included. Some states ask buyers to self-report use tax on out-of-state purchases.

Seymour Duncan STC-3P 3-Band Tone Circuit For Passive Pickups

The STC-3P is a professional-grade active preamp built to unlock clarity, articulation, and tonal flexibility from any bass fitted with passive pickups. This pre-wired harness installs into your control cavity with minimal downtime, delivering low-noise, high-headroom amplification that reshapes passive tone while keeping the fundamental character of your instrument intact—essential reliability for gigging and session work.

Electronics & Tone Control

Built around a high-headroom, low-noise 3-band active EQ preamp, the STC-3P operates with exceptional clarity and minimal distortion across its full range. The circuit accommodates both single 9v battery operation and optional series wiring of two 9v batteries for additional headroom, giving you control over your preamp's dynamic ceiling when you need extra punch on stage.

Controls & Integration

The pre-wired harness includes concentric bass and treble knobs, dedicated mid-range control, master volume, blend control, and a proprietary Slap Switch—all mounted on high-quality potentiometers with knurled black dome-style knobs for precise, reliable operation. A stereo jack and battery clip complete the installation, making this circuit compatible with any bass featuring two passive pickups and space for four control knobs plus a single 9v battery cavity.

Key Features

High-headroom, low-noise 3-band active EQ preamp
Concentric bass and treble controls with dedicated mid-range control
Master volume and blend control
Proprietary Slap Switch for enhanced articulation
Pre-wired harness with high-quality potentiometers
Stereo jack connection
Battery clip included for 9v power
Knurled black dome-style control knobs
Single 9v battery operation (two 9v batteries can be wired in series for added headroom)
Designed for passive bass pickups in any configuration with two pickups
Low distortion and high signal clarity across full frequency range
Compact footprint: 4.00" W x 1.50" H x 9.00" D, 1.20 lbs

The STC-3P brings the tonal authority and responsiveness of active electronics to the stage while preserving the organic warmth of your passive pickups—built for players who demand both flexibility and reliability.

Condition	New
Country of Manufacture	United States