Pre-Wired Harness

Any of the Pre-Wired Harnesses from Bartolini work with any of our pickups to create an active volume and tone control system for your bass or guitar. A professionally pre-wired harness saves the time and aggravation of wiring your preamp and pots into your instrument. They feature our pro-level preamps and premium audio-quality pots and switches with smooth control and ready for years of rugged use. There are over 100 configurations to choose from varying by volume controls, tone controls and active/passive options.

As a pro-level artist, you can fine tune your voice by choosing the right preamp and controls for your instrument. We make 2-band and 3-band EQ preamps with different frequency responses and control ranges in a lot of different configurations. To find your pre-wired preamp harness, you can start by finding your preamp or start with finding your control layout. Or you can do a quick search if you already know what you want.

Start by Finding Your Control Layout

Browse the many layouts available. All pre-wired harnesses include an output jack and battery clips. Everything is pre-soldered with pro-quality pure copper wire that is double tin plated and protected with semi-rigid insulation so it won’t flop around in the cavity or degrade over time. The pots and jack are all grounded for noise rejection and are flexible to fit a variety of hole patterns. We use only professional lead-free solder with non-corrosive flux. Click a graphic to see the preamp and control options in that layout.

5 Knob + 1 Switch Control Layout

This is a common upgrade for many modern basses with 3-band EQ controls and a toggle switch.

5 Knob Control Layout

This is a common upgrade for many modern basses with stock 3-band EQ controls.

4 Knob + 1 Switch Control Layout

This layout is popular in a lot of instruments for many years.

4 Inline Knob + 1 Switch Control Layout

This is a popular layout in custom-made Jazz basses.

4 Knob Control Layout

One of the most common layouts for both bass and guitar with Les Paul style.

4 Inline Knob Control Layout

This is the most popular upgrade in Jazz bass layout.

3 Knob Control Layout

This is a common upgrade for Jazz Bass, Music Man, and many guitars for improved control.

2 Knob Control Layout

This layout is common in P Bass and many others with a single pickup or selector switch.

Or Start by Finding Your Preamp

Your voice is a combination of your pickups, strings, instrument materials and construction, and playing technique. Your ability to boost and cut the right frequencies as needed are key to controlling your voice. Check out the frequency response graphs below. The charts below show the frequency response envelopes of the different preamp choices. Don't worry if you don't fully understand the charts - there is more description on the pages that link from here. Click a graphic to get more info about each preamp and the controls and layouts available.

NTMB+F 3-Band EQ

Our most popular preamp for decades, the NTMB+F is a 3-band tone control preamp with fully independent Bass, Mid and Treble controls has very low noise and wide boost/cut range for aggressive control. The sound is extremely clear and transparent. The high frequency treble response allows for a bright and sparkly tone when you need it. The NTMB+F features an adjustable gain which allows you to boost the input signal up to 4X while maintaining flat frequency response.

NTMB+FL 3-Band EQ

NTMB+FL is similar to the NTMB+F but with tighter adjustment range and lower Treble frequency. Often used in fretless instruments for more focused mid control, the FL voice is the same as the original Bartolini TMB from the 1980s. The boost/cut range is limited for more precise control, and the treble response provides a warmer voice. NTMB+FL also has adjustable gain for up to 4X extra boost.

NTBT-918 2-Band EQ

NTBT-918 is a 2-band tone control preamp with fully independent Bass and Treble controls with very low noise and wide boost/cut range for aggressive control. The NTBT-918 features an adjustable gain which allows you to boost the input signal up to 4X while maintaining flat frequency response.

TCT Vintage 2 or 3-Band EQ --Special Order--

TCT is the original Bartolini on-board preamp. It has Bass, Mid, and Treble controls with very low noise and wide adjustment range and can be used in 2-band or 3-band mode. Bass and Treble bands can be boosted or cut. The Mid band is narrow notch cut for excellent slap tone. An MCT mid boost module can be added for full boost and cut of the mid. TCT is the original Bartolini preamp with inter-dependent controls, so it is a tone shaping preamp rather than a strict EQ and requires expertise. TCT Pre-Wired Harnesses are available as Special Order and will take several weeks for delivery.

XTCT Vintage 2 or 3-Band EQ --Special Order--

XTCT is identical to the TCT except the mid cut frequency is 500Hz vs. 300Hz to provide thicker sounding bass. Like the TCT, it is a vintage, complex product where each frequency band adjustment affects the other bands as well.  XTCT is a tone shaping preamp rather than a strict EQ and requires expertise to install and use. XTCT Pre-Wired Harnesses are available as Special Order and will take several weeks for delivery.