Bartolini HR-5.2ap/918 3 Bands 5 Knobs (Vol P/P Bal. Treble Mid Bass)

A Bartolini Classic: The NTMB+F Platform, Celebrated for Decades

Based on the highly regarded NTMB+F, this preamp is presented as one of Bartolini's most popular models for decades. Its philosophy is simple: preserve the character of your instrument while offering an impressive range of adjustment, with a clean grain and balanced response, appreciated both in the studio and on stage.

For Bassists Who Want Expressive Active Electronics Without Compromise

The HR-5.2ap/918 is designed for musicians who demand immediate and musical control: switching from a modern, punchy sound to a more present midrange to cut through the mix, or reinforcing the low-end foundation. The Pull-Bypass on the volume knob allows quick switching to passive operation (depending on your wiring), handy for live use or when the battery is low.

Premium Harness: Professional Wiring, Premium Components, Simplified Installation

This harness is delivered fully pre-soldered with audio-quality potentiometers and switches, providing a smooth rotation feel and durability designed for intensive use. Bartolini supplies battery clips and a 6.35mm Jack output to speed up assembly. All potentiometers are grounded via a dedicated wire, to be connected to the cavity shielding (or removed if unnecessary). The wiring uses pure copper with double tinning and semi-rigid insulation to prevent wire movement inside the cavity or degradation over time. Soldering is done with lead-free solder and non-corrosive flux.

Knobs are not included (personal choice), except when a stacked (concentric) potentiometer is present: in that case, a "ring" knob and a center knob are provided.

Technical specifications

Category	spare part	Quantity	1
Instrument	Bass

Brand	Bartolini	Assembly	pre-wired and pre-tested harness in workshop
Model	HR-5.2ap/918	Components	audio-quality potentiometers and switches
Type	onboard preamp / pre-wired harness	Included	battery clips, 6.35mm Jack output
EQ	3 Band EQ (Bass, Mid, Treble)	Grounding	potentiometers grounded via wire (to connect to cavity shielding or remove if unnecessary)
Controls (5 potentiometers)	Volume with Pull-Bypass switch, Blend (Balance), Treble, Mid with 250/800Hz push-pull, Bass	Wiring	pure copper wire, double tinned, semi-rigid insulation
Sound signature	very low noise, wide boost/cut range, clear, transparent, and powerful voice	Soldering	lead-free, non-corrosive flux
Treble setting	fixed high frequency for maximum available brightness	Knobs	not included, except ring + center knobs provided for concentric potentiometer