Controls
The M228 has four controls and two footswitches, laid out as follows1:
| Control | What it does |
|---|---|
| CLEAN knob | Adjusts wet/dry signal mix added to the compressor's output |
| OUTPUT knob | Adjusts volume of compressed signal |
| ATTACK switch | Toggles between slow and fast attack times |
| SENSITIVITY knob | Adjusts sustain time |
| TONE knob | Shapes EQ of compressed signal |
| FOOTSWITCH | Toggles effect on/bypass (blue LED indicates on) |
The Clean knob is the addition most players ask about. Dunlop's own history of the Dyna Comp line describes it this way31:
The M228's INPUT jack is where the chain starts: Dunlop's own guidance for the pedal is to "Run a cable from your guitar to the M228's INPUT jack"31.
The Attack switch works as a two-position toggle: push it to move between the default slow attack time and a fast attack time, indicated by a red LED1. A fast attack clamps the front of each note sooner, while the slow setting lets more of the initial pick attack come through before the compression takes hold.
Power
The M228 runs on 9 VDC and draws 11 mA1. It takes one 9-volt battery, fitted by removing the bottom plate, or an external supply. Dunlop specifies the ECB003 9-volt adapter, or the DC Brick and Iso-Brick power supplies1.
The manual specifies a 9 VDC supply. Use the Dunlop ECB003 adapter or a compatible supply such as the DC Brick or Iso-Brick, and confirm polarity and current ratings against the manual before powering the pedal on a shared daisy chain.
Impedance, levels and noise
The manual gives the following specifications, measured by Dunlop1:
| Specification | Value |
|---|---|
| Input Impedance | 600 kΩ |
| Output Impedance | 25 kΩ |
| Max Input Level | -5 dBV |
| Max Output Level | +2 dBV |
| Noise Floor | -100 dBV (A-weighted, all controls mid position) |
| THD | 0.2% (measurements made at -20 dBV, 1 kHz) |
| Max Compression | 36 dB |
A 600 kΩ input impedance is high enough that the pedal will not load down a passive guitar's pickups noticeably, and the -100 dBV noise floor figure, measured with all controls at mid position, is quiet for a pedal of this type. The -5 dBV maximum input level is worth noting if you run hot active pickups or a loud boost in front of the pedal1.
Where it came from
Dunlop's documentation for the M228 Dyna Comp Deluxe sets out the pedal's basic connections, instructing players to "Run a cable from your guitar to the M228's INPUT jack"31.
Setup
The manual's signal path is straightforward1:
- Run a cable from your guitar to the M228's INPUT jack.
- Run another cable from the M228's OUTPUT jack to your amplifier.
Review video
Dunlop's guidance for the MXR Dyna Comp Deluxe covers the pedal's input connection, telling players to "Run a cable from your guitar to the M228's INPUT jack"21.
Videos
Algam EKO
MaxReviews Pro
Questions
What does the Clean knob do on the MXR Dyna Comp Deluxe?
The Clean knob adjusts the wet/dry signal mix added to the compressor's output. Dunlop describes it as allowing players to blend in the unaffected signal, restoring bite and immediacy at whatever level works best. That means you can keep the sustain of the compressed signal while bringing back as much of your untouched guitar tone as you want.
Does the M228 Dyna Comp Deluxe take a 9V battery?
Yes. According to Dunlop's manual, the Dyna Comp Deluxe Compressor is powered by one 9-volt battery, and you remove the bottom plate to install it. It can also run on a 9 VDC power supply such as the Dunlop ECB003 adapter, or the DC Brick and Iso-Brick power supplies, drawing 11 mA.
What does the Attack switch do on the M228?
The Attack switch toggles between slow and fast attack times. Push it to switch between the default slow attack time and a fast attack time, which is indicated by a red LED. A fast attack clamps the front of each note sooner, while the slow setting lets more of the initial pick attack through.
How much compression does the M228 offer?
Dunlop's manual lists a maximum compression figure of 36 dB. The SENSITIVITY knob adjusts sustain time, so you set how much compression and sustain the pedal applies, and the OUTPUT knob sets the volume of the compressed signal.
What chip does the Dyna Comp Deluxe use?
The M228 uses the CA3080 'metal can' IC, which Dunlop describes as giving it the superior vintage tone of the original Dyna Comp circuit. In a Sweetwater demo video, Brian Kehoe of Dunlop Manufacturing noted that it features the CA3080 circuit found in the original Dyna Comp and the original Dyna Comp script logo version.
Sources (3)
- M228.pdf, Jim Dunlop, 2019
- MXR M228 Dyna Comp Deluxe Compressor Pedal, Sweetwater, 2018-08-31
- A Dyna Comp-rehensive History, Dunlop (lifestyle.jimdunlop.com), 2018-10-25
