UnderToneAudio MPDI-4 Four-Channel Microphone Preamp

Product Description

The UnderToneAudio MPDI-4 packs four discrete microphone preamp and DI circuits into a single 1RU chassis. Each channel pairs a discrete Class A gain stage with bypassable transformers, switchable output headroom, and adjustable THD characteristics, giving the MPDI-4 the flexibility to sound surgically clean or rich with harmonic color. Use the UnderToneAudio MPDI-4 four-channel microphone preamp on drums, vocals, guitars, and acoustic instruments and dial in the perfect amount of analog warmth for any track. Straightforward front-panel controls make it easy to commit to sounds during the recording process, so your mic pre can help you get closer to the sound in your head instead of chasing it with plug-ins later. Discover the UnderToneAudio MPDI-4 four-channel mic preamp and get better sounds quicker.

UNMATCHED SONIC VERSATILITY

Three tone-shaping tools are responsible for the MPDI-4 four-channel mic preamp's tonal versatility. Bypassable input and output transformers let you choose between full-throated analog grit and a cleaner transformerless preamp path that passes +27 dBu at only 0.003% THD. A switchable 600 Ohm output load drives the MPDI-4 into the harmonic distortion territory of classic console mic pres, adding rich color and warmth to any source. The -10 dB output pad anchors the switchable output headroom scheme of the MPDI-4, letting you push the mic preamps hard without clipping your converters. Whether you want to bring a little color to your digital workflow or lean all the way into analog tone, the UnderToneAudio MPDI-4 mic preamp's adjustable THD characteristics make it possible.

FRONT PANEL CONTROLS

The MPDI-4 four-channel microphone preamp is equipped with easy-to-use front panel options including a rotary switch covering the -10 to -60 dB boost range in 5 dB increments, a -20 dB input pad, the -10 dB output pad, phase reverse, +48 V phantom power, transformer bypass, and the 600 Ohm load switch. A switchable low impedance mode drops the input of the UnderToneAudio MPDI-4 mic pre to 500 Ohms for passive ribbon microphones, while the 2 kΩ setting suits condensers, dynamics, and any other traditional mic. The preamp's XLR-1/4" combo jack doubles as an instrument DI, inserting an active Class A JFET stage automatically when you plug in a bass or synth. One switchable output meter serves all four channels on the MPDI-4 mic preamp, saving space without sacrificing functionality.

REAR PANEL INPUTS AND OUTPUTS

The rear panel of the UnderToneAudio MPDI-4 hosts an XLR mic pre input and XLR mic pre direct line output for each channel. Duplicate front-panel inputs mean you can leave the MPDI-4 four-channel mic pre wired up to a patch bay and still plug a mic or instrument into the front. Bypassing the output transformer gives an alternate output character, and the 47 Ohm output impedance of the UnderToneAudio MPDI-4 drives long cable runs and converter inputs without loss. Engage the output transformer instead, and the MPDI-4 adds low-end weight and harmonic texture before the signal ever leaves the mic preamp.

THE UNDERTONEAUDIO LEGACY

UnderToneAudio was founded by producer/engineer Eric Valentine and electronics designer Larry Jasper, who spent four years building a no-compromise large-format analog console before adapting its Class A circuitry for rack gear like the MPDI-4 four-channel mic preamp. Eric Valentine has made records with Queens of the Stone Age, Slash, and Nickel Creek, and his obsessive engineering mindset shows in every component of the MPDI-4 four-channel mic preamp. The same UnderToneAudio mic pre circuit anchors the MPEQ-1, which pairs it with the company's powerful HP/LP filters and EQ. The UnderToneAudio MPDI-4 four-channel microphone preamp puts console-grade UnderToneAudio circuitry into a single rack space unit for a fraction of the price of the console that inspired it.