Quest Engineering PB-4120, Owner'S Manual, Page: 5 / 14

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PB-4120
Features
• The amplifier delivers 120 watts of clean power per channel at 70/100 volts and 4 Ohms,
with 4 x 120 watts.
• Class D amplifier operating at 85% efficiency using universal power supplies with power
factor correction and capable of operating from 100-240 V, 50 or 60 Hz. The PB-4120
amplifiers generate virtually no heat and thanks to their low current draw.
• Built-in 70/100 volt output transformers with flat frequency response from 40Hz to 20kHz
provide constant voltage for distributed speaker systems.
• Independent input level controls for each channel allow precision adjustments and the
included security panel provides protection from unwanted adjustment.
• Clean, crisp sound - Impressive audio specifications such as 0.04% THD, dynamic range
of 105 dB, crosstalk of 80 dB, and frequency response of 10 Hz to 25 kHz guarantee ultra-
clean sound quality.
• LED signal indicators for each channel continuously display power output levels and allow
you to correct for overloading (clipping) conditions.
• Forced air cooling via internal fan provides reliable performance without thermal and
overheating problems.
• Protection circuitry (with dedicated LEDs for each channel) that guards against
overheating or faulty wiring conditions and also prevents “thumps” when powering on or
off. This means that you can use the PB-4120 with a single power strip, into which a mixer
or other audio devices are connected, without danger of damage to connected speakers.
• Input connections for each channel are made using Euroblock connectors to
accommodate both balanced and unbalanced signals sources.
• Output connections for each channel are made using Euroblock connectors which accept
12 gauge wire.
• The PB-4120 can be mounted in any standard 19” rack (taking just two rack spaces),
making it easy to integrate into any fixed or traveling PA rig.
• The amplifiers are enclosed in ruggedly construction (an all-steel chassis with a sleek black
finish), standard 2-space 19-inch rack mount unit.
The Jam industry PB-4120 power amplifiers have been developed using the latest
technology in Class D power amplifier design. Here are some of their main features:
Features