The Rane MPE 28 is a MIDI programmable equalizer from Rane Corporation, a rack unit that stores equalizer curves and recalls them under MIDI control. It belongs to Rane's family of MIDI programmable EQs, alongside the Rane MPE 141.
Memories and editing
The MPE 28 holds curves in 128 Stored Memory locations, with a Working Memory scratch pad for the curve being edited. Rane preset programs 1 to 21 at the factory, so the unit arrives with curves already stored in the first locations1.
Editing and recall are handled from the front panel:
- BYPASS toggles between Bypass and Active modes, with the LED on in Bypass. Pressing it routes all audio in the unit around the equalizer electronics1.
- CURVE WEIGHT weights curves and sums two curves together1.
- LEVEL / EXPRESS sets the overall level of the equalizer in EQ Edit mode, and sets Expression parameters when not in EQ Edit mode1.
- UP & DOWN increase or decrease parameters in all operating modes1.
- EQUALIZER Display is a numeric green LED display showing the boost/cut level of an individual filter or the overall Level, active only in EQ Edit mode1.
- OL (Overload indicator) is a red LED that illuminates any time the input, filters or output reaches 4dB below clipping1.
Inputs, outputs and MIDI
The MPE 28 carries both XLR and quarter-inch connectors, all balanced, so it sits comfortably in a rack or PA signal path as well as a guitar rig1.
| Connector | Type | Balanced wiring | Unbalanced use |
|---|---|---|---|
| 3-pin INPUT | Active balanced, XLR | Pin 2 is (+), pin 3 is (, ), pin 1 is signal ground, shell is chassis ground | Connect pins 3 and 1 together and drive pin 21 |
| ¼" INPUT | TRS balanced | Tip is (+), ring is (, ), sleeve is ground | Use a TS plug, or connect ring and sleeve together on a TRS plug1 |
| 3-pin OUTPUT | Active balanced, XLR | Pin 2 is (+), pin 3 is (, ), pin 1 is signal ground, shell is chassis ground | Not specified1 |
| ¼" OUTPUT | TRS balanced | Tip is (+), ring is (, ), sleeve is ground | Leave the ring open1 |
MIDI is central to the unit's design, with three 5-pin connectors:
- MIDI IN allows the MPE 28 to respond to external MIDI control1.
- MIDI OUT transmits MIDI Program Changes and similar messages to the input of another MIDI device1.
- MIDI THRU contains all the MIDI information exactly as it comes into the MIDI input, unaffected by the MPE 28's controls, and is normally used for daisychaining1.
The MIDI channel is selectable from 1 through 16, or OFF1.
Grounding and power
A GROUND LIFT switch gives the user the option to tie signal ground to chassis ground. Rane notes that typically a system is quieter in the LIFT position, a useful remedy for hum in larger setups. A chassis ground point, a 6-32 screw, is provided for chassis grounding purposes1.
The power input is not a standard pedal-style DC jack. Rane specifies an AC supply delivering 18 to 24 volts from a center-tapped transformer, and instructs: "USE ONLY A RANE MODEL RS 1, RAP 10, FRS 8 OR OTHER REMOTE AC POWER SUPPLY APPROVED BY RANE."1
Rane backed the MPE 28 with a two-year parts and labor warranty1.
Questions
How many memories does the Rane MPE 28 store?
The MPE 28 provides 128 Stored Memory locations for equalizer curves, plus a Working Memory scratch pad for the curve being edited. Rane preset the first 21 Stored Memory locations, programs 1 to 21, at the factory, so the unit ships with usable curves already in place.
Does the Rane MPE 28 have a true bypass?
The manual describes a Bypass mode rather than true bypass: pressing the BYPASS button routes all audio in the unit around the equalizer electronics. The button toggles between Bypass and Active modes, and the LED lights when the unit is in Bypass.
What power supply does the Rane MPE 28 use?
The MPE 28 takes an AC supply delivering 18 to 24 volts from a center-tapped transformer. Rane specifies using only a Rane model RS 1, RAP 10, FRS 8 or another remote AC power supply approved by Rane.
What does the Ground Lift switch do on the MPE 28?
The Ground Lift switch gives the user the option to tie signal ground to chassis ground. Rane notes that typically a system is quieter in the LIFT position, which helps with hum caused by ground loops.
Does the MPE 28 have balanced inputs?
Yes. The unit offers both a 3-pin (XLR) active balanced input and a quarter-inch tip-ring-sleeve balanced input. Both can also be run unbalanced: on the XLR input, connect pins 3 and 1 together and drive pin 2; on the quarter-inch input, use a TS plug or connect ring and sleeve together on a TRS plug.
What is the warranty on the Rane MPE 28?
Rane covered the MPE 28 with a two-year parts and labor warranty, according to the operating and service manual.
Sources (1)
- MPE 28 MANUAL, Rane Corporation, 1994-05