Comparison: Rockman Smart Gate / MXR M135 Smart Gate
Update: MXR M235 Smart Gate Pro now available at Musicians Frined
MXR M235 Smart Gate Pro
Update: New MXR Custom Shop Smart Gate
Dunlop is in the process of rolling out it's new custom shop line of products. The first two products will be
the MXR rack Wah and a Dual Smart Gate. This is the unit EVH was using during the 2004 Best of Both Worlds tour.
The Custom Shop Smart Gate circuitry is exactly the same as the small M-135 MRX Smart Gate, except that the rack runs on
a 18 Volt power supply, which offers ~6dB more headroom and has true hard-wire bypass. Each gate has a front panel
bypass switch enabling the gate to be bypassed regardless of the rear panel bypass. The two internal gates can be
configured to be bypass alternately, or bypassed individually and the output of the first Smart Gate can feed the input of
the second Smart Gate through the second gate's input jack.
The Dunlop custom shop is now open.
Click here for the Dunlop Custom Shop
Original Smart Gate Article
The first question many of you are probably asking is "Why would I need a noise gate?"
Tube amps are noisy creatures especially high gain tube amps like the 5150, Eddie Van Halen
uses the Rockman Smart Gate to quiet his 5150's. When referring to noise we are talking about the hiss
and hum you hear when not playing. A noise gate will eliminate this static by filtering the frequency
band that generates this hiss and hum, a good noise gate will eliminate the single coil hum as well.
Here is the real trick…a good noise gate will do this without coloring your tone in any way, shape or form.
And this is where the MXR/Rockman Smart Gate out performs all other noise gates until the recent release of
the MXR Smart Gate.
The rest of this article will cover the Rockman Smart Gate, the MXR Smart Gate and the differences and
similarities between the two units.
Rockman Smart Gate
Production: Approximately 1,940 units from 1989-1994
Suggested list price: $189.00
Form Factor: Half rack Rockman Rock Module
The Rockman Smart Gate was developed from the noise reduction circuitry initially designed for the Rockman
Sustainer. Consensus among tone gurus is the Rockman Smart Gate is the best noise reduction device ever
developed, EVH uses two Smart Gates in his stage rig. With no processing circuitry in the signal path
while the gate is open the gate releases time as notes either cut or decay. The end result is total
silence at any volume level.
The Rockman Smart Gate has three areas that control how the unit functions: Noise Band Cut, Trigger/Thresh
Hold Adjust and Line/Guitar Level. The Noise Band Cut switch lets you select the filter cut-off point.
This allows the noise gate to be tailored to different input signals. The HISS GATE works well with vocal
mikes, keyboards an electric bass while the HISS/MID GATE is effective on distorted guitars, amplified
harmonicas and high gain midrange instruments. The FULL BAND is most effective in quieting low-end hum and
buzz generated from AC line noise, display noise (PC monitor) and noise generate from light dimmers.
The Threshold Adjust sets the gate sensitivity level. A yellow light indicates when the gate is engaged
allowing the user to set the threshold level to each input source. The Line/Guitar Level button allows
the Smart Gate to be used with a wide range of input sources. Typically leaving the button out for
instrument inputs is acceptable.
MXR M-135 Smart Gate
Production: Currently Produced
Suggested list price: $174.98
Form Factor: Stomp Box
The main difference in the MXR Smart Gate from Rockman Smart Gate is the form factor. The Rockman unit is
a half rack design while the MXR Smart Gate is a stomp box measuring 4-3/8 x 2-3/8 x 1-1/4 inches.
The controls are basically the same with the footswitch toggling the Effect On/Bypass (red LED indicates on).
The Trigger Level knob allows adjusting the threshold level of gate versus the Rockman's slider and a
three-position switch selects type of noise reduction: Hiss, Mid Range, or Fuji Gate. These setting
perform exactly as the Rockman units Noise Band Cut switch.
Rockman - MXR Differences
MXR Smart Gate is an improved version of the Rockman Smart Gate. The MXR and the Rockman Smart Gates
produce the exact same selectable 3-band Smart Noise Reduction results along with the following
- The MXR Smart Gate detection/decision circuitry uses Full-Wave instead of Half-Wave as in the Rockman, thus improving the smoothness of the Noise Filtering action.
- The MXR Smart Gate uses VCA (Voltage Controlled Amplifier) technology to vastly improve the percent of THD when compared to the Rockman FET (Field Effect Transistor) approach.
- The MXR Smart Gate is powered by a single standard 9-volt battery or AC wall adaptor.
- Reduced in size to fit in a small bullet proof "Stomp Box"
As a Rockman collector the two pieces of Rockman gear that I cannot live without are the Rockman Stereo
Echo and Smart Gate. The Rockman Smart Gate sits in the effects loop of my ADA MP1 which is notorious
for producing excessive noise and hum. The Smart Gate keeps the old MP1 quiet along with the hum from
the single coils. When recording on the PC I use the Rockman Smart Gate between my guitar and Line6
GuitarPort to reduce the noise generated by the PC monitor. In short you cannot have enough of these
devices and my next "tone" purchase will be a MXR Smart Gate for the live rig.
I would like to thank the engineers at Jim Dunlop for providing information on both the Rockman and MXR
To discuss this article in the Wolfgang Registry forums click here.
More Smart Gate information can be found at the following site:
Jim Dunlop MXR M135 Page
Harmony-Central Rockman Smart Gate Database
MXR M-135 Smart Gate Pedal