The ISP Technologies Decimator X is a guitar noise reduction pedal. ISP says the Decimator X offers "unparalleled transparency and smoothness in noise reduction," and describes it as ideal for both live performances and studio recordings1. The company notes that foreign patents are pending on the design2. It carries a list price of $177.00 USD3, and gearnews.com's reviewer wrote that "for two decades it's been enough to make it the pedal other noise gate pedals get measured against"3.
The one-knob control
The Decimator X has exactly one control: a Threshold knob. Guitar World's 2026 noise gate buying guide lists its controls as Threshold only, and notes that the pedal relies on signal analysis to control its other parameters, so there is nothing else to set4.
| Control | What it does |
|---|---|
| Threshold | The pedal's only knob; everything else is set internally by signal analysis4 |
Julian Schmauch, writing in gearnews.com's noise gate guide, put it plainly: "One knob. That's the Decimator X's entire interface"3.
What that means in practice is that the pedal's release behavior is handled internally. ISP describes the pedal's adaptive design as covering41:
- Advanced adaptive noise reduction, which the company describes as offering unparalleled transparency and smoothness1
- An advanced adaptive release mechanism for seamless transitions between fast staccato notes and long sustained tones1
- Linearized Time Vector Processing1
In practice, the adaptive release is the company's way of saying the gate tightens up quickly between picked notes and lets sustained notes decay naturally instead of cutting them off1.
The single-knob approach sits at the heart of how reviewers frame the pedal. Schmauch wrote that "for two decades it's been enough to make it the pedal other noise gate pedals get measured against," describing players' sense of it as ducking the noise floor rather than slamming a door shut3.
Power and connections
The Decimator X runs on either a 9V battery or a 9V DC power supply, and ISP is explicit that the supply is sold separately. Current draw is 35mA1.
The 9V DC power supply is not included. At 35mA the pedal is within reach of most pedalboard power supplies, but a battery or a separately purchased 9V DC adapter is needed to run it.
Connections are minimal: one 1/4" input and one 1/4" output, with no send/return loop14.
That is where the Decimator G String X comes in. Schmauch explains the difference: "the Decimator X G-String gates in two places at once, in front of the amp and inside the effects loop, keyed off the same detection"3. Guitar World notes that ISP says this dual unit approach yields better results than the four-cable method4. For a player with a high-gain amp loop, the G String X is the version built for that; the plain Decimator X handles a single inline position.
| Decimator X | Decimator G String X | |
|---|---|---|
| Controls | Threshold only4 | Threshold only4 |
| I/O | 1 x 1/4" in, 1 x 1/4" out1 | Adds 2 x 1/8" link in/out jacks5 |
| Enclosure | 2.3" H x 2.7" W x 5" D1 | 2.3" H x 2.7" W x 5" D5 |
| Power | 9V battery or 9V DC supply, sold separately; 35mA1 | Same 9V DC arrangement; 35mA1 |
| Patent | US Patent 11,641,1831 | US Patent 11,641,1835 |
ISP Technologies describes the Decimator X as offering "unparalleled transparency and smoothness in noise reduction," and positions it as ideal for both live performances and studio recordings1.
Where it sits among noise gates
gearnews.com's reviewer wrote that "for two decades it's been enough to make it the pedal other noise gate pedals get measured against," which places the Decimator X as a long-standing reference point among noise gates3. It carries a list price of $177.00 USD3.
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Questions
Does the ISP Decimator X run on a battery?
Yes. ISP Technologies lists a single 9V battery among the pedal's power options, alongside a 9V DC power supply input. The pedal draws 35mA, and the DC supply is sold separately, so a player who wants to run it from a pedalboard power supply needs to budget for one.
Is the power supply included with the Decimator X?
No. ISP Technologies lists the power source as a 9V DC power supply, sold separately. The pedal can also run on one 9V battery, but if you plan to power it from a pedalboard supply or adapter, that supply is an additional purchase.
How many knobs does the Decimator X have?
One. The single Threshold knob is the pedal's entire interface. ISP's design relies on signal analysis to set the pedal's other parameters automatically, so there are no secondary controls for release time, decay or mode.
What does adaptive release mean on a noise gate?
On the Decimator X, ISP describes an advanced adaptive release mechanism that handles the transitions between fast staccato notes and long sustained tones. In practice, the release behavior follows the playing rather than sitting at one fixed setting, which is what the company says keeps the reduction smooth rather than abrupt.
What is the Decimator X patent number?
ISP Technologies lists the Decimator X's adaptive noise reduction technology under US Patent 11,641,183, with other foreign patents pending.
How big is the Decimator X?
ISP Technologies gives the enclosure as 2.3 inches high, 2.7 inches wide and 5 inches deep, the same footprint the company lists for the Decimator G String X.
Sources (5)
- ISP Technologies, ISP Technologies
- The All New Decimator X Adaptive Noise Reduction Pedal, ISP Technologies, 2024-05-31
- The 7 Best Noise Gate Pedals of 2026: Not Hiss Problem (or Hers), gearnews.com, 2026-07-27
- Best noise gate pedals 2026: clean up your signal, Guitar World, 2021-03-19
- ISP Technologies, ISP Technologies
