A Designs MP-2 Microphone Preamp

by Russ Long

Product Points

Applications: Studio Key Features: 48V phantom power; polarity reverse; tube design; VU meter Price: $1,499 Contact: A Designs at 818-716-4153, Web Site. A Designs MP-2 Mic Preamp Plus + good price + great sound Minus - Difficult to make small adjustments (the MP-2's latest version corrects this problem) - No instrument input (the MP-2's latest version corrects this problem as well) - No front panel 1/4-inch input The Score The MP-2 provides the smooth warmth of analog while maintaining a crystal clear spectrum of sound all within the price range of most studio budgets. Review Setup Apple 400 MHz PowerMac G4 Pro Tools v5.1.3 Mix+; iZ Technologies RADAR 24 with Nyquest 96 kHz card; Lucid Gen-X-96 clock; Mogami cabling; Hafler amplification; PMC TB1, Yamaha NS-10M monitors; GML 8200 parametric EQ; TubeTech CL-1B, Empirical Labs Distressor compressors; Sony C-800G, Brauner VM1-KHE, Royer R-122 and SF-1, AKG D112, Shure SM-57 microphones.

Features

The 2RU MP-2 is 10 inches deep and weighs 18 pounds. The front panel of the box has identical controls for each channel. The level control adjusts the gain from 0 to 46 dB. The polarity switch inverts the phase of the preamp's input. Its switch positions are labeled 0 and 180. An output switch sets the output impedance at either 600 ohms or 10 kohms. Its switch positions are labeled 600 and 10k. The phantom power switch provides 48V phantom power to the microphone input when activated. Its switch positions are labeled On and Off. If the phantom power is switched off while the mic is still plugged in, there will be a 10 second delay before it is completely off. Each channel is also equipped with a backlit VU meter.

Also on the front panel is a power switch that activates power to the unit and a red jewel lamp that illuminates when the unit is turned on. The 220 volt model has a blue jewel lamp. Unfortunately, the units are not user switchable between 110 and 220 volts. The MP-2 manual recommends that the preamp is allowed at least two to five minutes warm-up time before use. I seemed to get the best results after allowing the box at least 30 minutes of warm-up time.

The rear panel is equipped with a pair of Neutrik combo XLR/1/4-inch input connectors that will accept either a male 1/4-inch or male XLR connector for audio input. The input impedance is 1.4 kohm. On the unit I reviewed, both the 1/4-inch and the female XLR were setup for microphone input. This has since changed and now the female XLR is for microphone input and the 1/4-inch is a DI for instrument input. A pair of male XLR connectors provides audio output. A standard IEC connector provides AC input.

The box's output is a Low-Z, transformer-balanced signal with a maximum level of +22 dBu. With a frequency response of 20 Hz - 60 kHz and a THD .08 @ 1 kHz, the MP-2 should find itself welcome in even the most sonically demanding recording scenarios.

The MP-2 has a one-year limited warranty for internal parts, a 30-day limited warranty for labor and a 30-day limited warranty for tubes. A Designs has already had an overwhelmingly positive response to the MP-2 and has recently announced the release of the MP-2R, a variation of the MP-2 optimized for use with ribbon microphones. The MP-2R has more gain than the MP-2 and has an input impedance designed to work perfectly with classic ribbons such as the Coles 4038 and the RCA 77DX, as well as modern masterpieces such as the Royer R-121 and SF-12.

In Use

During a tracking session I put one channel of the MP-2 to work on the drum set's kick drum with a D 112 and the other on the snare using an SM-57 and had great results in both cases. On the kick I found the bottom end to be far more tight and punchy than the sound I have typically achieved with a tube mic pre, and the snare had a wonderful sparkle that seemed to be enhanced by the tubes. On another tracking session I was able to use the MP-2 with a pair of Royer SF-1s and a pair of Empirical Labs Distressors to record drum kit ambience; again I had great results.

I put the MP-2 to use recording electric guitars for Canton, Ohio's Relient K, and had wonderful results. I found that placing a Royer R-122 about four inches from a Marshall 4 x 12 cabinet and running through the MP-2 needed no additional processing. I ran directly out of MP-2 into an iZ Technologies RADAR hard disk recorder and recorded fabulous sounding electric guitars.

Next I went to work recording vocals through the MP-2 with a Brauner VM1KHE and a Sony C-800G (both tube mics). In both situations I ran the preamp's output into a GML 8200 EQ and Tube Tech CL1B compressor and had fantastic results. I also found that the MP-2 did a nice job smoothing off the edge of an Audio-Technica 4033 while recording female backing vocals. I was also able to use the box in several situations while recording a track for an animated children's film and found that it worked well recording accordion, tuba and slide whistle.

Since the rear panel's 1/4-inch input has been updated to be an instrument instead of a microphone input, I would like to see additional 1/4-inch inputs on the front panel. It is often a pain in the studio to climb behind a rack to plug in a guitar cable and the convenience of having inputs on the front panel would be worth a slightly higher cost as far as I am concerned. The only other complaint I have with the MP-2 is that I found it difficult to make small adjustments with the level control due to its extreme sensitivity. A Designs' Pete Montessi confirmed that this was a complaint by a few of his customers so he altered the volume control design so this will not be the case in the future. It is refreshing to see that there are still companies that listen to their customers and will actually alter their products to better meet their needs.

Summary

The A Designs MP-2 is a simple, straightforward, affordable stereo tube mic preamp of exceptionally high-quality packed into a 2 RU box. The pre may be just the answer for those from the project studio needing a single high-quality mic pre to handle all of their recording needs, to a full production studio needing to add an option to their preamp selection pallet.

Russ Long, a Nashville-based producer/engineer, owns The Carport recording studio. He is a regular contributor to Pro Audio Review.