A Designs Audio MP2A Stereo Tube Preamp

There aren’t many single preamps that engineers and producers feel that they could solely use to make an entire record, but according to industry professionals, A-Designs Audio has built two: The all-tube MP-2A and the solid-state Pacifica. But we’re here to talk about the MP-2A (you can check out the Pacifica later). Designed to provide the versatility and sonic majesty the discerning professional requires for top-quality recordings, the A-Designs MP-2A not only offers two tone switches per channel (four distinct sounds), custom transformers, plus polarity (phase) switches in order to treat any sound source as desired, it also gets top marks in “works and plays well with others.” Meaning, while some preamps can be finicky when it comes to certain mics, the MP-2A welcomes all and sounds great no matter what you put through it; ribbon, dynamic, or condenser. Whether you’re looking for clarity and transparency, or the rich, euphonic sound of input tubes driven hard, the MP-2A can give you all that and more.   

Each channel features a -20dB pad; two selectable tone switches for four possible tones on each channel; 60db gain for use with next-generation ribbon mics; and Cinemag input transformers coupled with custom-wound output transformers, delivering the low noise and top-quality sound you demand from a high-end preamp. Additional features include balanced combo XLR/1/4” inputs, true VU meters, phantom power, polarity switches, and front-panel, line-level input jacks.   

Built to audiophile-quality standards with a price tag well below other boutique preamps in its class, the MP-2A has no integrated circuits in the signal path—it relies solely on discrete components, namely tubes, film capacitors, and custom transformers. To maintain the integrity and purity of its sonic signature, bells and whistles are kept to a minimum. This serves two purposes: First, the more switches in the circuit path, the more sound quality can be negatively affected. Second, by keeping only necessary features, costs are kept down and your money goes where it really counts: sound quality.   

Unlimited “Sweetspot” and Tonal Variation
With many preamps, you’ll find that they tend to have only one setting where you hear “the magic.” Move past it, and the magic is gone. The problem with a single-setting sweetspot is that you can’t always run the preamp at that setting, since the strength of the input signal will vary from sound source to sound source. Not so with the MP-2A! Thanks to its fixed-gain amplifier with output attenuator, you get consistent behavior (the magic) whether the MP2-A is turned up or down. It also provides polarity switches, which allow you to record a stereo sound source out of phase in order to enhance stereo imaging, or tame overwhelming bass via cancellation. Factor in the tone switches that give you a palette of four unique sonic flavors on each channel, and you can easily see why we say you could make an entire record with just this one incredibly versatile preamp.

Features:

• All-tube design
• Selectable tone switches offer four sounds per channel
• 60dB gain allows use of next-generation ribbon mics
• EF86 input tubes/6N1P output tubes
• Cinemag input transformers and custom-wound output transformers
• True VU meters
• Dual level controls
• -20dB pad switch (per channel)
• Polarity switch (per channel)
• Toroidal power transformer
• Balanced XLR I/O and 1/4” direct injects
• Custom-milled faceplate, solid vented metal frame (2U rack size)

Specifications:

• Frequency Response: 20Hz – 60kHz
• Gain range: 0 – 60dB
• Distortion THD: > .08 @ 1kHz
• Noise (EIN): -128dBu
• Input impedance: 1.4k ohm
• Phantom power: +48V switchable power source
• Mic input phase: 0-180” (switchable)
• Instrument input: 1/4” phono
• Instrument input impedance min: >100k ohm
• Output impedance: 600 ohm, switchable to 10k ohm
• Maximum output level: +22dBu
• Output: Low-Z, transformer-balanced
• Power requirements: 100/120/230 VAC – 42W
• Dimensions: (W x H x D) 19” x 3-1/2” x 10”
• Weight: 18 lb.