Microphone processor and preamplifier ART ProChannel II

ART ProChannel II is a versatile microphone processor and preamp that combines the quality of classic tube sound with modern technology to create unparalleled audio. This device features a fully discrete Class A preamp and has a front input with a 1/4" high-impedance connector, providing convenience for connecting instruments.

The ProChannel II features plate voltage regulation. The built-in optical compressor has separate attack and release controls, as well as a switch for automatic/manual attack and release. The compressor/limiter allows adjustment of attack time from 250 microseconds to 100 milliseconds and release time from 100 milliseconds to 3 seconds, with a compression ratio from 2:1 to 30:1. This compressor also includes a VU meter and LED indicators for accurate signal monitoring. Two insert loops are provided with level switching options of +4/-10 dB for optimal sound output.

The processor has a toroidal power transformer that reduces noise. The input impedance for the microphone input ranges from 150 to 3.4 kΩ, while for the instrument input it is 2.5 MΩ. The balanced output impedance is 600 Ω, and the unbalanced output is 300 Ω.

The processor provides a wide frequency range from 12 Hz to 100 kHz with minimal distortion (THD) – less than 0.015 % at 1 kHz and less than 0.033 % at 20 Hz – 20 kHz. The equivalent input noise for the microphone and line inputs is -128 dBu and -109 dBu, respectively, ensuring clean and transparent sound.

The ProChannel II supports a maximum input signal level of +18 dBu for the microphone input and +15 dBu for the instrument input. The maximum gain for the microphone input is up to 70 dB, and for the instrument input – 64 dB.

The ProChannel II also features a parametric equalizer with boost/cut capabilities of up to 12 dB on each of the four frequency bands. The low-frequency filter has a range of adjustment from 10 to 250 Hz, and the equalizer allows fine-tuning of low, mid, and high frequencies.

Features

• Fully discrete Class A preamp
• Front input with 1/4" high-impedance connector
• Built-in optical compressor with separate attack and release controls
• Automatic/manual attack and release switch
• Compressor/limiter with attack time adjustment from 250 microseconds to 100 milliseconds and release time adjustment from 100 milliseconds to 3 seconds
• Compression ratio: from 2:1 to 30:1
• VU meter and LED indicators for signal monitoring
• Two insert loops with +4/-10 dB level switching options
• Toroidal power transformer
• Input impedance: microphone – from 150 to 3.4 kΩ, instrument – 2.5 MΩ
• Output impedance: balanced – 600 Ω, unbalanced – 300 Ω
• Frequency ranges from 12 Hz to 100 kHz
• Distortion (THD): less than 0.015 % at 1 kHz, less than 0.033 % at 20 Hz – 20 kHz
• Equivalent input noise: -128 dBu (microphone), -109 dBu (line)
• Maximum input signal level: +18 dBu (microphone), +15 dBu (instrument)
• Maximum gain: 70 dB (microphone), 64 dB (instrument)
• Parametric equalizer with boost/cut up to 12 dB on each of the four bands
• Low-frequency filter: adjustment from 10 to 250 Hz

User Manual