ART ProMPAII to-kanals diskret klasse A mikrofonforstærkeramp Brugermanual

1. Introduktion

The ART ProMPAII is a two-channel discrete Class A microphone preamplifier designed to deliver high-performance audio. It features variable input impedance, selectable 48V phantom power, and can be configured for dual mono or stereo operation. The unit incorporates two hand-selected 12AX7 tubes, allowing for a wide variation of preamp tone and performance through selectable low or high plate voltage. Large backlit analog VU meters and multi-colored LED arrays provide visual feedback on input/output levels and tube gain. Housed in a durable 2-space rack-mountable steel chassis with an aluminum face panel, the ProMPAII is built for reliable operation in various professional audio environments.

2. Nøglefunktioner

• Variabel indgangsimpedans: Offers flexible microphone voicing from 150 Ohms to 2400 Ohms.
• Selectable Plate Voltage: Choose between low or high plate voltage for varied preamp tone.
• Discrete Class-A Input Microphone Preamplivligere: Ensures high-quality audio amplifikation.
• Lav støj: Achieves low noise levels, especially at lower gain settings.
• Extremely Low Total Harmonic Distortion (THD): Maintains signal purity.
• Bred frekvensrespons: Captures a broad range of audio frequencies.
• Large Backlit VU Meters: Provides clear visual monitoring of output levels.
• Backlit Function Switches: Enhances visibility and usability in various lighting conditions.
• Additional Front Mounted Instrument Input Jack: Supports direct connection of instruments (e.g., guitar, bass, keyboard).
• Supports Mid/Side Miking Technique: Allows for advanced stereo recording configurations.
• Operates at +4dbm/-10dbv Output: Compatible with professional and consumer-level equipment.
• Selectable Stereo/Dual Operation: Provides flexibility for two independent channels or linked stereo operation.
• Automatic Instrument Input Selection: Simplifies setup when connecting instruments.

3. Opsætningsvejledning

Follow these steps to set up your ART ProMPAII:

1. Udpakning: Carefully remove the ProMPAII from its packaging. Inspect the unit for any signs of damage.
2. Placering: The ProMPAII is designed for rack-mounting and occupies two standard rack spaces. Ensure adequate ventilation around the unit.
3. Strømtilslutning: Connect the provided power cord to the AC inlet on the rear panel of the ProMPAII and then to a suitable AC power outlet. Ensure the power switch on the front panel is in the OFF position before connecting.
4. Mikrofonforbindelser:
   • Connect your microphones to the XLR inputs on the rear panel. The ProMPAII supports two independent microphone inputs.
   • If using condenser microphones requiring phantom power, ensure the +48V phantom power switch is engaged for the respective channel on the front panel.
5. Instrumenttilslutninger: For direct instrument input, use the 6.35mm (1/4-inch) jack on the front panel. Connecting an instrument to this jack automatically bypasses the rear XLR input for that channel.
6. Udgangsforbindelser: Connect the outputs of the ProMPAII to your audio interface, mixer, or recording device using appropriate cables (XLR or 1/4-inch TRS). The unit supports both +4dBu and -10dBV output levels.

Figur 3.1: Frontpanel overview of the ART ProMPAII. This image displays the various controls and indicators on the front of the unit, including the power switch, gain knobs, impedance selectors, output level controls, low cut filter knobs, and the instrument input jack. The two large backlit VU meters for Channel One and Channel Two are prominent, along with their respective control switches for gain, phantom power, plate voltage, and phase. The central "Tube Warmth" and "Mid/Side Matrix" indicators are also visible.

4. Betjeningsvejledning

This section details the operation of the ART ProMPAII's controls and features.

4.1. Kontroller på frontpanelet

• Afbryderen: Slår enhedens strøm til og fra.
• GAIN knap: Adjusts the input gain for each channel. Rotate clockwise to increase gain.
• IMPEDANCE Knob: Varies the input impedance (150 Ohms to 2400 Ohms) to optimize performance with different microphones (e.g., dynamic, ribbon).
• MASTER OUTPUT LEVEL Knob: Controls the overall output level of the respective channel.
• INSTRUMENT (High Z) Jack: 1/4-inch input for connecting high-impedance instruments.
• LOW CUT FILTER Knob: Adjusts the high-pass filter frequency (7.5 Hz to 200 Hz) to remove unwanted low-end rumble.
• VU målere: Large backlit analog meters display the output level for each channel.
• TUBE WARMTH LEDs: Multi-colored LED arrays indicate the level of tube gain/saturation.
• GAIN +20dB Switch: Engages an additional 20dB of gain for low-output microphones.
• +48V kontakt: Aktiverer fantomstrøm til kondensatormikrofoner.
• PLADEVOLTAGE (High/Normal) Switch: Selects between high and normal plate voltage for the 12AX7 tubes, affecting the tonal characteristics.
• PHASE (Normal/Invert) Switch: Inverts the phase of the input signal, useful for correcting phase issues in multi-microphone setups.
• MID/SIDE MATRIX (Active) Switch: Engages the Mid/Side decoding function, summing the adjacent channel for stereo processing.
• DUAL/STEREO Switch: Selects between independent dual-channel operation or linked stereo operation.

4.2. Grundlæggende betjening

1. Tænd: Flip the POWER switch to the ON position. The VU meters and tube warmth LEDs will illuminate.
2. Forbind kilde: Connect your microphone or instrument as described in the Setup Guide.
3. Indstil forstærkning: Start with the GAIN knob at its minimum setting. Gradually increase the GAIN while monitoring the VU meters to achieve a healthy signal level without clipping. Adjust the +20dB switch if more gain is needed.
4. Adjust Impedance: Experiment with the IMPEDANCE knob to find the optimal setting for your microphone. This can significantly alter the microphone's tonal response.
5. Apply Phantom Power (if needed): If using a condenser microphone, activate the +48V switch for the corresponding channel.
6. Select Plate Voltage: Choose between HIGH or NORMAL plate voltage to achieve the desired tube warmth and character. HIGH voltage typically provides more headroom and a cleaner sound, while NORMAL can offer more saturation.
7. Use Low Cut Filter: Engage and adjust the LOW CUT FILTER knob to remove unwanted low-frequency noise (e.g., stage rumble, air conditioning hum).
8. Skærmoutput: Use the MASTER OUTPUT LEVEL knob to fine-tune the signal sent to your recording device or mixer, ensuring it does not clip at the destination.
9. Stereo/Dual Mode: Use the DUAL/STEREO switch to select between independent channel operation or linked stereo control. For Mid/Side miking, activate the MID/SIDE MATRIX switch.

5. Vedligeholdelse

Proper maintenance ensures the longevity and optimal performance of your ART ProMPAII.

• Rensning: Brug en blød, tør klud til at rengøre enhedens yderside. Undgå slibende rengøringsmidler eller opløsningsmidler.
• Ventilation: Sørg for, at ventilationsåbningerne ikke er blokerede for at forhindre overophedning.
• Udskiftning af rør: The 12AX7 tubes are designed for long life, but may eventually require replacement if performance degrades (e.g., increased noise, reduced warmth). Tube replacement should be performed by qualified personnel or by following specific instructions from ART. Always disconnect power before attempting any internal maintenance.
• Opbevaring: When not in use for extended periods, store the unit in a cool, dry place, protected from dust and extreme temperatures.

6. Fejlfinding

This section provides solutions to common issues you might encounter with your ProMPAII.

7. Tekniske specifikationer

• Model: Pro MPA-II
• Type: Two Channel Discrete Class A Microphone Preamplivligere
• Indgangsimpedans: Variable (150 Ohms to 2400 Ohms)
• Fantomkraft: Selectable +48V
• Rør: Two 12AX7 (hand-selected)
• Plade Voltage: Selectable Low/High
• Outputniveauer: +4dBu / -10dBV selectable
• Forbindelser: XLR (rear), 6.35mm (1/4-inch) Jack (front)
• Chassis materiale: Steel (rack-mountable) with CNC routed black anodized aluminum face panel
• Dimensioner (H x B x D): Cirka 3.46 x 18.98 x 8.74 tommer (8.79 x 48.21 x 22.20 cm)
• Vægt: Cirka 12.1 pund (5.49 kg)
• Strømkilde: Elektrisk med ledning
• Dato først tilgængelig: 2. oktober 2001

8. Garanti og support

For warranty information and technical support, please refer to the official ART webwebstedet eller kontakt deres kundeservice direkte. Gem din købskvittering som købsbevis i tilfælde af garantikrav.

Online ressourcer: Visit the ART website for product registration, FAQs, and additional support documentation.

Kontakt support: Refer to the contact information provided in your product packaging or on the official ART webwebsted for direkte hjælp.