ISP Hum Extractor + Decimator G

A modern solution to the classic pedalboard challenge: hum and hiss

Background noise has multiple origins: there is the mains hum (50 Hz / 60 Hz), often dependent on the room, lighting, proximity to transformers, and guitar orientation, and there is the hiss generated by gain stages (overdrives, distortions, preamps, high-gain amps). The ISP Technologies Hum Extractor + Decimator G is designed to address both issues uncompromisingly by combining a dedicated hum suppression block and a Decimator block aimed at gain noise. The result: a quieter rig, more consistent from one venue to another, and above all more enjoyable to play daily.

Who benefits and in which styles the Hum Extractor + Decimator G makes a difference

This pedal is intended for guitarists (and bassists depending on configuration) who want signal cleanliness without sacrificing attack, dynamics, and feel. If you play with single-coil pickups, record in a home studio, or switch between very defined clean tones and high gain levels, this is typically the kind of tool that changes the game.

In rock and metal, it helps tame hiss between riffs, makes palm mutes crisper, and avoids unwanted squeals when muting strings. In blues, funk, or pop, it excels at preserving quiet clean tones even when hum becomes audible as soon as you slightly open the volume. On stage or in the studio, it allows you to maintain a "clean" signal that facilitates the work of sound engineers and mixing.

Key features: 2 channels, flexible placement, and fine control

The Hum Extractor + Decimator G is a 2-channel DSP processor designed for strategic insertion in your signal chain. The HUM EXTRACTOR block is generally placed upstream (between the guitar and the rig input) to suppress mains hum at the source. The channel 2 is then placed after gain sources (preamp, distortions, effects loop depending on your setup) to handle hiss and noise generated by amplification.

Highlight: the placement of the HUM EXTRACTOR block is selectable (channel 1 or channel 2) to adapt the pedal to more complex setups. The Decimator relies on a level detection derived from the direct signal (after hum components are removed), improving tracking and noise reduction precision when your signal becomes cleaner, subtler, or more dynamic.

The pedal combines three operations: hum suppression, Decimator-type downward expansion (noise reduction when the signal fades), and a dynamic sliding high-frequency filter inspired by the brand's rack solutions. Adjustment is done via dedicated thresholds (HUM EXTRACTOR and DECIMATOR) and a FILTER TRACKING control to fine-tune how the dynamic filter follows your high-frequency content. Once set, the interaction becomes intuitive: you play, the filter opens on your harmonics and naturally closes to reduce hiss, including on low notes.

Sound character

The goal here is not to add color but to preserve your tone. The Hum Extractor aims for completely transparent hum suppression: attack remains sharp, chords keep their openness, and pick nuances do not turn into an overly aggressive gate effect. The Decimator works to ensure clean note-offs without unnecessary "pumping," while maintaining a natural playing feel when you roll down the guitar volume or switch from an arpeggio to a saturated riff.

In practice, you get a quieter chain, better clarity in the upper spectrum, and a more usable perceived gain: less residual noise, more definition, and better-controlled dynamics, especially useful with high-gain presets, boosts, or heavily saturated amps.

Technical specifications

Effects	Compressor, Noise Gate	Type	sector
Technology	Digital	Use	electric guitar
Format	Pedal	Color	Black

Effective noise reduction	over 80 dB	Frequency response	20 Hz - 20 kHz = +0 dB / -0.5 dB
Input impedance	470 kOhms	Outputs	maximum level +13.5 dBu
Input level trim	21.5 dB / input level from -8 dBu to +13.5 dBu	Note	0 dBu = 0.775 VRMS
Maximum input signal	+13.5 dBu	Dimensions	7.15 inches (W) x 1.85 inches (H) x 4.5 inches (D) (approx. 181.6 mm x 47.0 mm x 114.3 mm)
Floor noise	-104 dBu A WTD	Weight	1.2 lbs (approx. 0.54 kg)
Dynamic range	117 dB A WTD	Required power supply	9V AC (RMS)
Decimator / max red noise	80 dB	Current	1500 mA (1.5 A)