AudioRoot uPRE MKII

AudioRoot uPRE MKII

The AudioRoot uPRE MKII is a portable two-channel microphone preamplifier with analogue and digital outputs. It combines two electronically balanced microphone inputs with 48V phantom power, a wide gain range and digital output at up to 24-bit/192kHz.

The preamp runs on two 9V batteries or an external DC supply. It can therefore serve as a separate microphone front end for a recorder, using either the analogue connection or a suitable digital input.

Main Features

• Two electronically balanced microphone inputs through mini-XLR connectors.
• 48V phantom power on each channel.
• Gain range from −50 to +80 dB.
• 80Hz high-pass filter with a 12 dB per octave slope on both channels.
• Stereo linking and M/S decoding.
• Unbalanced analogue stereo output through mini-XLR5.
• AES or S/PDIF digital output.
• Three LEDs per channel for level indication, plus a low-battery indicator.

Stereo and M/S

Stereo linking allows the channels to be controlled together. The M/S decoder enables processing of a Mid/Side microphone signal. AudioRoot also describes operation as a mono mixer.

Analogue and Digital Connections

The analogue stereo output is unbalanced and uses a 5-pin mini-XLR connection. For digital connection, the uPRE MKII supports AES, the default setting, or S/PDIF.

The digital output operates at 24-bit resolution with sample rates of 44.1, 48, 88.2, 96, 176.4 and 192 kHz. The connected recorder must support the selected digital format and sample rate.

Power

The uPRE MKII runs on two 9V batteries or an external 9–18V DC supply through its Hirose connection. Switching between battery and external power is automatic.

AudioRoot specifies approximately five hours of operation with condenser microphones and the A/D converter enabled, or up to ten hours with dynamic microphones and the A/D converter disabled. Actual runtime depends on the microphones and batteries used.

Specifications

• Channels: 2.
• Input impedance: >5 kΩ.
• Gain range: −50 to +80 dB.
• Distortion: 0.003% at 40 dB gain.
• Frequency range: 10 Hz–70 kHz.
• Maximum output level: +17 dBu.
• Digital resolution: 24-bit, up to 192 kHz.
• External power: 9–18V DC.
• Housing: polyamide and aluminium.
• Dimensions: 130 × 85 × 30 mm.
• Weight: 255 g.

Included

• AudioRoot uPRE MKII microphone preamplifier.

According to current manufacturer information, the cable kit and external mains power supply are available separately.

Optional Cable Kit

The uPRE MKII cable kit provides connections for microphones, the analogue stereo output and the AES output:

• 2 × mini-XLR to XLR3F microphone input cables.
• 1 × mini-XLR to 2 × TA3F analogue stereo output cable.
• 1 × mini-XLR to XLR3M AES output cable.

uPRE MKII and FEMTO Compared

The AudioRoot FEMTO provides two microphone channels with a balanced analogue output and OLED display. The uPRE MKII adds digital output, stereo linking and M/S decoding.