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Roland MMP2

Mic Modelling Preamp By Hugh Robjohns
Published November 2002

This new front end from Roland combines two high-quality analogue mic preamps with digital EQ, dynamics, and physical modelling effects. Plus, you can choose to control it from its front panel or from a computer via USB.

Whilst the majority of mic preamps are all-analogue affairs, Roland's MMP2 utilises much of the physical modelling effects technology developed in their VS and VM-series products, presenting it all in a compact silver box with chunky illuminated buttons. This two-channel unit provides a pair of balanced microphone inputs plus a stereo S/PDIF digital input, with two balanced (XLR) analogue line outputs, S/PDIF and AES-EBU digital outputs, and a USB socket. Only the front end and the line outputs are in the analogue domain — everything else is digital.

Roland MMP2 Mic Modelling Preamp.Once amplified and converted to digits (24-bit resolution and sample rates from 44.1 to 96kHz), the signal is cast into a wealth of DSP, and processed with a simple mic modelling facility, configurable four-band parametric equalisation, comprehensive dynamics processing (including expansion, de-essing and modelled valve compressors), and preamp modelling. Patches can be edited and stored internally, of course, and also remotely over the USB port to a computer (Mac and PC drivers are supplied).

Hardware Layout

The basic layout of the machine is simple enough. The analogue input strips occupy the left-hand side, while the centre portion contains three configuration buttons and an Enter key, a two-line LCD with three associated soft knobs, a pair of Page navigation buttons, and a set of eight more buttons used to bypass and edit the four signal-processing sections. The rear panel features an IEC mains inlet and power switch; the two analogue line outputs, with a slide switch to select +4dBu or an unusual -16dBu operating level; the USB port; S/PDIF input and output phono connectors; and an AES-EBU XLR output. Unusually, there are no MIDI sockets at all, as Roland have decided that any remote control functions can be done via the USB link and a computer. Fine in a studio environment, but not so handy for the gigging musician who wants to change patches in several different pieces of equipment with a single MIDI command.

Roland MMP2 £499
  • Quiet mic preamps.
  • Analogue and digital I/O.
  • Comprehensive processing facilities.
  • Excellent editor program.
  • EQ and preamp modelling not simultaneously available.
  • Panel ergonomics can be frustrating.
  • No permanent onboard metering facility.
  • Not able to act as a USB audio interface.
A digital mic processor offering mic modelling, EQ, comprehensive dynamics, and preamp emulation, all in a compact but high-quality unit. A USB interface allows remote control through an excellent graphical user interface, but sadly no audio interfacing.


The first of the four configuration buttons at the top of the panel selects a metering function to the LCD screen. Each channel is represented by ten blocks drawn across the screen, forming a bar graph which spans the range from -48 to 0dBFS. The display can be switched between input or output levels, or dynamic gain reduction.

You cannot, unfortunately, view the meters at the same time as adjusting any process parameters — which also use the screen display. So, for example, setting up dynamic processing is fiddly and convoluted, as you have to adjust the ratio and threshold by ear, and then move to the gain-reduction metering page to see how much compression is being applied, followed by switching back and forth to set the appropriate amount of make-up gain. This involves a ridiculous amount of button pushing — it wouldn't have been so bad if you were returned to the menu page you exited from to view the meters, but instead you have to scroll through from the start each time! To be honest, a simple LED bar graph on the panel somewhere would have made the operation of this unit a whole lot easier.

The next button is associated with the patch memories — selecting from the factory and user presets, storing new or modified presets, and resetting the selected patch parameters to default values (modelling off, unity gain in the EQ, and dynamics off). There are 43 factory and 64 user presets — although as shipped the factory presets are also repeated to fill up the user patches.

Obviously, only the user presets can be modified and overwritten. Cycling through the various presets illuminates the Edit Select buttons to reveal which of the four processes are employed in each patch.

The System button accesses the digital clock facilities, USB parameters, and various other housekeeping functions. The first menu allows the input source to be selected between the analogue mic input and the S/PDIF input, the clock source to be set between the internal generator or an external digital input, and the sample rate (for internal clock mode) from 44.1, 48, 88.2, or 96kHz.

Analogue Circuitry

The two input channels are equipped identically, starting with a pair of mic input connections in the form of Neutrik combi jack/XLRs (accepting either XLR or TRS jack connectors) on the top panel. Only the XLR connections receive phantom power (if selected). Blue buttons below the connectors engage a 20dB pad, allowing keyboard and line signals to be processed through the box if required. The input impedance is a surprisingly high 40kΩ, so line inputs won't be loaded, and the inputs can accommodate up to +22dBu with the pad, or +2dBu without. Roland recommend turning the gain right down and selecting the input pad if a channel is unused, to minimise noise.

Roland MMP2 rear panel.In fact, the Equivalent Input Noise for the mic input is claimed to be an astonishing -132dB (IHF-A), and it certainly sounds very quiet and clean. I tried it with both low-output dynamic mics and high-output condensers and it seemed to turn in a great performance with both. A pair of rotary knobs scaled from -16 to -64dB (or +4 to -44dB with the pad engaged) set the input gain. I found that the noise level rose sharply right at the end of the gain control's rotation — a common artefact of most budget mic preamps. A red LED for each channel indicates peak levels at -3dBFS. The illumination of this lamp can be reprogrammed, if desired, to provide earlier warning at -6dBFS or a pointless, 'you've just blown it' indication at 0dBFS.

The phantom power supply can source a maximum of 6mA which is adequate for the vast majority of capacitor mics — although there are a few which demand rather more — the latest CAD M-series models require 8mA, for example. I found it would power one CAD M179 happily enough, but I'm not sure how it would cope with a pair, and I believe the various international specifications for phantom power recommend a supply capable of at least 10mA, so the Roland is a little tight in this regard.

To activate phantom power there are illuminated push buttons for each channel which recall a menu to the LCD window. Besides the phantom power, this menu also controls signal polarity, a high-pass filter (adjustable between 20Hz and 2kHz), and a digital attenuator. The last two buttons in the input strip, marked Edit Ch Select, enable access to the assignable signal processing for each channel, and activate stereo link and copy facilities.

Mic Modelling & Digital Processing

Each of the four processing stages — Model (mic modelling), EQ, Dynamics, and Plug-in (preamp modelling) — has its own illuminated bypass button below the LCD screen. Associated with these bypass buttons are four more buttons which allow the parameters for each section to be edited through the LCD screen. Note that, although each processing section has its own separate button, the EQ and Plug-in sections cannot both be used simultaneously.

The mic modelling section allows you to set the reference (source) and output microphone type, the amount of proximity effect, and the amount of delay. The latter can be used to match the phase of the signals from different mics recording the same source. The reference mic models include three dynamics (a named Roland model, a generic one, and a headset mic), plus two condensers (a generic miniature one and the AKG C3000B) and a flat reference. The output models include a generic small-diaphragm dynamic, a vocal dynamic (with a pronounced mid-range), a large-diaphragm dynamic, a small-diaphragm condenser (with a bright high end), a large-diaphragm condenser, a vintage condenser, and a flat reference. Not as comprehensive a range as some mic modellers, but certainly enough for creating useful effects.

The equaliser is a typical digital affair, with four freely configurable bands and an input attenuator to ensure a reasonable headroom is maintained through the processing. All bands provide ±15dB gain and span 20Hz to 20kHz, and any one of nine filter types can be chosen for each: peaking, low and high shelving, first- and second-order low- and high-pass filters, band-pass and band-reject. The Q controls range from a very broad 0.36 to a notch-like 16, and are disabled if the shelving or first-order filters are selected.

The dynamics section seems the most complex of the lot, partly because several different dynamic processes are all accessed through the same menu. It kicks off with a compressor, but this is followed by an expander and an enhancer/de-esser — and all have a lot of control variables! The compressor offers a solid-state emulation plus four valve effects, with a key channel selection for music ducking effects. The controls are as you'd expect, with threshold, ratio, knee (hard or soft), attack, release, make-up gain, and an automatic make-up mode.

The expander is also equipped with key channel selection, and has controls for threshold, ratio, attack, and release, but no range, hysteresis or hold time. The enhancer/de-esser block lets you select one of these two processors, and a sensitivity control sets the threshold upon which the high frequencies are boosted or reduced (depending on which mode is operating). A frequency control selects the range where processing is applied, and a pair of level controls determine the boost for the enhancer and the cut for the de-esser. Given that only one function can be active at a time, I don't understand why there are two separate level controls, but it's not a problem.

Like all dynamics processing 'less is more', in that a subtle approach almost always provides a better end result — unless you are deliberately seeking to squeeze the pips out of the source for effect. I found that the compressor worked well, and the tube options provided a reasonably smooth, warm character. The expander could be used to good effect with some noisy sources, and the enhancer and de-esser, when carefully set up, provided a useful degree of additional control or sparkle, depending on the source.

The plug-in modelling section is intended to replicate the characteristics of a number of classic preamp sections — Focusrite Red 7, Neve 1073, and various other solid-state and valve designs. The different options have an audible effect, although some are very subtle indeed and just how accurate they are is open to debate. If you find a particular sound you like, fine, but take it all with a large pinch of salt. Strangely, having gone to the trouble of apparently emulating various classic preamps, Roland have then gone on to offer the choice of changing the sound character completely with controls for warmth, brightness and harmonic distortion.

USB Interface & Editor

The MMP2 ships with drivers on a CD-ROM and a USB lead to allow connection with a computer. Installation of the Windows driver was simple enough on one of my Windows 98 systems (Windows 2000 is also supported on the disc), and the Mac version apparently uses a USB MIDI driver which allows communication through OMS or FreeMIDI. With the driver installed, plugging the MMP2 into a spare USB port prompted instant recognition from the operating system.

With the communications established, it is possible to control all of the MMP2 functions remotely, and with rather greater flexibility and considerably more ease, through a bespoke software editor. This provides an attractive visual interface which shows all of the unit's facilities for both channels, at a single glance. There are individual control sections for the mic modeller, equaliser, dynamics and preamp elements, all with the full array of controls and parameters with very traditional, analogue styling. Best of all, not only are there meters for both input and output levels (shown simultaneously), but also separate gain reduction meters for the compression and expansion elements of the dynamics processors — joy of joys! Even the glow of the virtual valves showing through the bottom of the control screen is quite appealing. I found I enjoyed using the MMP2 most when I was setting a patch up through the USB editor, and then saving this patch for instant recall from the unit itself.

The USB connection also makes it possible to exchange patches between computer and processor, which is handy for archiving preset groups. However, the one facility which would have made this a truly versatile box is missing. It does not appear to be possible to pass audio over the USB link, into the computer for use with a DAW program. This is a real shame, as the MMP2 would have had a much wider appeal if it was possible to use it as a front end for a computer without the need for a sound card. Okay, so you can always use the S/PDIF or analogue output and link it through a suitable soundcard, but a direct USB interface would have made it far more useful. A shame.

In A Nutshell

Overall, the MMP2 is a good-sounding unit. The basic analogue elements seem to be of very good quality, with a nice quiet preamp and decent converters. The digital processing is competent and plentiful, and although I'm no great fan of modelled mics and preamps generally, they provide an extra option for creativity which has to be a good thing. The EQ is flexible and versatile, as is the dynamics section, and aside from the minor operational frustrations already mentioned, the unit works very well indeed. There are some obvious shortcomings, both in terms of the ergonomics and the USB facility, but if you like what is being offered here, this is a solid and reliable performer.

infop.gif £499 including VAT.
infot.gif Roland UK +44 (0)1792 515020.
Published November 2002