The Rocktron HUSH Ultra is a rackmount noise reduction processor: a 19-inch unit that sits in your rack and strips hiss, hum and background noise from your signal while leaving your tone alone. Rocktron calls it "the ultimate noise reducing, eliminating and exterminating processor," and it delivers up to 72dB of effective noise reduction1. Unlike a simple noise gate pedal, it is a digital stereo unit with two channels, programmable presets, MIDI control, an LCD display and true bypass1.
It is a MIDI-controllable version of Rocktron's long-running HUSH noise reduction, the company's patented approach to cleaning up high-gain rigs1. At review time it carried an MSRP of $399 with a street price around $3002.
The controls: Hush Threshold, Gate Threshold and presets
The front panel is built around two threshold knobs, and understanding how they relate is the key to using the unit. The Hush Threshold sets the point at which a downward expander and dynamic filter kick in, gently pulling down material below your playing level. The Gate Threshold sets the level at which the gate begins to operate, hard-muting the signal once it falls below that point2.
| Control | What it does |
|---|---|
| Hush Threshold | Sets the point where a downward expander and dynamic filter kick in2 |
| Gate Threshold | Sets the level at which the gate begins to operate2 |
| Preset knob | Selects presets directly2 |
| Level button | Selects instrument-level or line-level signals2 |
| In/Out button | Engages and bypasses the unit2 |
| Store/Edit button | Saves and edits presets2 |
Because the unit is MIDI controllable, you can create your own presets for silencing different setups and recall them over MIDI, which is what separates it from Rocktron's simpler HUSH units like the HUSH Super C1. MusicPlayers.com found operation straightforward once the relationship between the two thresholds is understood, and credited the manual, which runs only 18 pages, with explaining it well2.
Power and connections: XLR, 1/4" and MIDI
The rear panel has two balanced XLR inputs and outputs and two unbalanced 1/4" inputs and outputs, so the unit fits both studio-style balanced rigs and standard guitar cabling2. MIDI In/Out/Thru jacks let it sit in a MIDI chain for preset switching2.
A reference level switch selects -10dB for instrument-level use between guitar and amp, or +4dB for line-level use in an effects loop2. MusicPlayers.com's reviewer preferred the effects loop placement, noting that in a low-impedance context such as an effects loop or studio rig there was no sonic difference at all with the unit in the chain2.
Power comes from a standard wall-wart-style supply through an input jack2. Rocktron specifies 9VAC at 2000mA, with current consumption of 405mA1.
The HUSH Ultra runs on 9VAC, not the 9V DC center-negative supply most pedalboards use. It cannot share a typical pedalboard power supply or daisy chain.
Specifications
| Specification | Value |
|---|---|
| Effective noise reduction | Up to 72dB1 |
| Dynamic range | 105dB1 |
| Frequency response | ±.5dB, 10Hz to 27kHz1 |
| THD + Noise | .041% @ 0dBu, 1kHz (typ)1 |
| Noise floor | -100dBu1 |
| Maximum input level | +15dB (+4 Ref.), +5dB (-10dB Ref.)1 |
| Input impedance (1/4" jacks) | 470K Ohms1 |
| Output impedance (1/4" jacks) | 100 Ohms1 |
| Dimensions | 19" x 4" x 1¾"1 |
Where it comes from: Rocktron's HUSH noise reduction
The reviewer at MusicPlayers.com noted that noise reduction can be more than a utility, pointing out that Dimebag Darrell of Pantera often used a noise reduction unit in a more extreme manner, as an effect, to make his rhythm playing more staccato2.
What reviewers said
MusicPlayers.com reviewed the HUSH Ultra in November 2011 and rated it 3.8 overall, which earned it the site's WIHO Award2. The reviewer's verdict on its core job:
"The best we can ask for is our tone without the noise, and the Hush Ultra performed admirably in this regard."
On the practical side, MIDI control "worked great in our live rigs," and the reviewer called the street price of around $300 "a fantastic price given the effectiveness of this unit coupled with its MIDI capabilities"2. The unit also came with a manual the reviewer described as very well written and easy to understand at only 18 pages2.
Videos
JGuitar129
Peter Gar
Questions
Is the Rocktron HUSH Ultra true bypass?
Yes. Rocktron lists the HUSH Ultra as a true bypass unit. MusicPlayers.com's reviewer found no sonic difference at all with the unit bypassed in a low-impedance context such as an effects loop or studio rig, which was the reviewer's preferred placement for it.
Can I use the HUSH Ultra in front of my amp or only in an effects loop?
Both work. A reference level switch on the unit selects -10dB for use between guitar and amp, or +4dB for line-level signals in an effects loop. The reviewer at MusicPlayers.com preferred it in the effects loop, but the front-of-amp placement is supported by the level switch.
Is the HUSH Ultra stereo?
Yes. Rocktron describes it as a digital stereo noise exterminator with two channels of noise reduction. The rear panel carries two balanced XLR inputs and outputs plus two unbalanced 1/4" inputs and outputs, so both channels can be connected at either connection type.
What is the difference between Hush Threshold and Gate Threshold?
The Hush Threshold sets the point at which a downward expander and dynamic filter kick in, while the Gate Threshold sets the level at which the gate begins to operate. MusicPlayers.com found operation straightforward once the relationship between the two controls is understood, and said the manual explains it well.
What power supply does the HUSH Ultra need?
Rocktron specifies 9VAC at 2000mA, with current consumption of 405mA. The unit takes a standard wall-wart-style supply through an input jack, so it is not a battery-powered or typical 9V DC pedalboard device.
Sources (2)
- HUSH Ultra Guitar Noise Reduction, Rocktron, 2024-08-28
- Rocktron HUSH Ultra Noise Reduction, MusicPlayers.com, 2011-11-11
