Altec Lansing 1707C - User Manual

Other manuals for Altec Lansing 1707C

Operating Instructions27 pages

Specifications8 pages

Operating And Service Instructions27 pages

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Summary

System Specifications

Frequency Response

Specifications for frequency response of direct and preamp outputs.

Total Harmonic Distortion (THD)

Specifications for THD of direct and preamp outputs.

Signal-to-Noise Ratio

Specifications for signal-to-noise ratio of direct and preamp outputs.

Detailed System Specifications

Power Output and Bandwidth

Continuous average, midband output power, and frequency bandwidth.

Distortion and Damping Factor

Intermodulation distortion and damping factor specifications.

Output Levels and Transformer Specs

Rated output levels for direct, preamp, and transformer outputs.

Equalization, Compressor;Limiter, and Tone Generator

Details on EQ, compressor/limiter functions, and tone generator features.

Power, Consumption, and Environmental Specs

Power requirements, consumption, temperature, dimensions, and weight.

System Block Diagram and Design Specs

Architects and Engineers Specification

Technical specifications for system design and installation.

Mainframe Overview and Specs

Specifications

Detailed technical specifications for the mainframe.

Mainframe Technical Details

Compressor;Limiter Details

Details on compressor/limiter threshold, ratio, and release time.

Electrical Connections and Power

Power Connections (120 Volt, 50;60 Hz)

Power Connections (100, 200, 220, or 240 Volt; 50;60 Hz)

AC Line Voltage Selection and Strapping Chart

Module Installation and Mounting

Installing Modules in the Mainframe

Signal Routing and Connectivity

Mute;Tone Generator Connections

Front Panel Controls and Setup

Front-Panel Controls, Switches, and Indicators

Initial Setup of an Input Module

Initial Setup of an Output Module

Initial Setup of the Mainframe

Mixer;Power Amplifier Operation

Rear-Panel Control and Connectors

Operating the 1707 C;1715 C Mixer;Power Amplifiers

Procedure for setting levels, filters, and compressor/limiter.

Service Instructions

Caution on Servicing

Warning regarding hazardous voltages and user-serviceable parts.

Service, Parts, and Support

Power Amplifier Bias Adjustment

Procedure for adjusting amplifier bias current.

Power Amplifier DC Offset Adjustment

Procedure for adjusting amplifier DC offset.

Schematic Diagram

Schematic

The main schematic diagram of the mixer/power amplifier.

Summary

System Specifications

Frequency Response

Specifications for frequency response of direct and preamp outputs.

Total Harmonic Distortion (THD)

Specifications for THD of direct and preamp outputs.

Signal-to-Noise Ratio

Specifications for signal-to-noise ratio of direct and preamp outputs.

Detailed System Specifications

Power Output and Bandwidth

Continuous average, midband output power, and frequency bandwidth.

Distortion and Damping Factor

Intermodulation distortion and damping factor specifications.

Output Levels and Transformer Specs

Rated output levels for direct, preamp, and transformer outputs.

Equalization, Compressor;Limiter, and Tone Generator

Details on EQ, compressor/limiter functions, and tone generator features.

Power, Consumption, and Environmental Specs

Power requirements, consumption, temperature, dimensions, and weight.

System Block Diagram and Design Specs

Architects and Engineers Specification

Technical specifications for system design and installation.

Mainframe Overview and Specs

Specifications

Detailed technical specifications for the mainframe.

Mainframe Technical Details

Compressor;Limiter Details

Details on compressor/limiter threshold, ratio, and release time.

Electrical Connections and Power

Power Connections (120 Volt, 50;60 Hz)

Power Connections (100, 200, 220, or 240 Volt; 50;60 Hz)

AC Line Voltage Selection and Strapping Chart

Module Installation and Mounting

Installing Modules in the Mainframe

Signal Routing and Connectivity

Mute;Tone Generator Connections

Front Panel Controls and Setup

Front-Panel Controls, Switches, and Indicators

Initial Setup of an Input Module

Initial Setup of an Output Module

Initial Setup of the Mainframe

Mixer;Power Amplifier Operation

Rear-Panel Control and Connectors

Operating the 1707 C;1715 C Mixer;Power Amplifiers

Procedure for setting levels, filters, and compressor/limiter.

Service Instructions

Caution on Servicing

Warning regarding hazardous voltages and user-serviceable parts.

Service, Parts, and Support

Power Amplifier Bias Adjustment

Procedure for adjusting amplifier bias current.

Power Amplifier DC Offset Adjustment

Procedure for adjusting amplifier DC offset.

Schematic Diagram

Schematic

The main schematic diagram of the mixer/power amplifier.

Overview

Function Description
Important Technical Specifications
Frequency Response
Total Harmonic Distortion (THD) (Ref 1 kHz)
Signal-to-Noise Ratio (A-weighted)
Continuous Average Power
Maximum Midband Output Power (Ref. 1 kHz at 1% THD)
Power Bandwidth (Ref. 1 kHz at rated output power)
Rated Output Level (Ref. 1 kHz, unbalanced)
Equalization (Shelving type)
Compressor/Limiter
Power Requirements
Dimensions
Net Weight
Usage Features
Maintenance Features

The Altec Lansing 1707C/1715C is a six-channel mainframe mixer/power amplifier designed for professional audio installations. This versatile unit can be configured as a six-in/one-out microphone mixer/amplifier or a one-in/six-out distribution preamplifier, adapting to various design tasks with ease and flexibility. Multiple 1707C/1715C mainframes can be linked together to accommodate systems requiring more than six input/output ports.

Function Description:

The core of the 1707C/1715C is a fully protected power amplifier, delivering 75 watts for the 1707C model and 150 watts for the 1715C model. It features six configurable ports that can function as either inputs or outputs. The mainframe integrates a compressor/limiter, low and high-frequency shelving equalizers, muting capabilities, remote volume control, and a built-in tone generator that produces four distinct sounds (buzzer, siren, single-tone chime, and repeating tone chime).

The signal path for each input module is routed to front-panel nominal/peak LED indicators and input channel level controls. The dual LED displays (green for nominal, red for peak) are pre-fader, monitoring the output level from the corresponding input module. The nominal (green) LED illuminates within an approximate 10 dB window, aiding in proper gain adjustment. The summing amplifier combines signals from the six input channels, tone generator output, and the link input. This summed signal drives the link output, and then passes through the EQ and compressor/limiter sections before reaching the preamplifier output and finally the main amplifier section.

The main amplifier section is equipped with comprehensive protection systems, safeguarding against short circuits, over voltage, thermal issues, spurious oscillatory waveforms, low AC line conditions, output DC detection, subsonic signals, and turn-on/turn-off transients. A signal overload circuit monitors the output stage, illuminating a front-panel CLIP LED indicator when high output signal levels may cause clipping.

Important Technical Specifications:

Frequency Response:

Direct Output: ±1 dB, 20 Hz - 20 kHz (1 watt output)
Preamp Output: ±1 dB, 20 Hz - 20 kHz (0.775 Vrms output, 600 Ω load)

Total Harmonic Distortion (THD) (Ref 1 kHz):

Direct Output: <0.05%, 20 Hz - 20 kHz (rated output power, 30 kHz low-pass filter)
Preamp Output: <0.05%, 20 Hz - 20 kHz (0.775 Vrms output, 600 Ω load, EQ flat, compressor/limiter off, 30 kHz low-pass filter)

Signal-to-Noise Ratio (A-weighted):

Direct Output (master at maximum): >80 dB below rated output power
Preamp Output: >75 dB below 0.775 Vrms output, EQ off, compressor/limiter off

Continuous Average Power:

1707C: 75 watts
1715C: 150 watts

Maximum Midband Output Power (Ref. 1 kHz at 1% THD):

1707C: 100 watts
1715C: 175 watts

Power Bandwidth (Ref. 1 kHz at rated output power):

Direct Output: >20 Hz - 20 kHz
Transformer Output: >50 Hz - 15 kHz

Damping Factor (Direct Output): >40, 20 Hz - 1 kHz

Rated Output Level (Ref. 1 kHz, unbalanced):

1707C: 24.5 Vrms/8 Ω load, 24.5 Vrms/4 Ω load
1715C: 24.5 Vrms/8 Ω load, 24.5 Vrms/4 Ω load
Preamp Output: 0 dBm, 600 Ω min. load (balanced)

Equalization (Shelving type):

Bass: ±12 dB at 100 Hz
Treble: ±12 dB at 10 kHz

Compressor/Limiter:

Threshold: -20 dB to +20 dB (continuously variable, Ref. 100 mVrms on Link input)
Compression Ratio: 1:1 to ∞:1 (continuously variable)
Release Time: 50 msec to 5 sec (continuously variable)

Power Requirements:

AC Mains: 100/120/200/220/240 VAC, 50/60 Hz
Battery: ±48 VDC bipolar (1707C: 1.5 amps maximum, 1715C: 3.0 amps maximum)

Dimensions:

Width: 19 inches (48.3 cm)
Height: 5½ inches (13.3 cm)
Depth: 13 inches (33.0 cm)

Net Weight:

1707C: 25 lbs. (11.4 kg)
1715C: 32 lbs. (14.5 kg)

Usage Features:

Configurable Ports: Six ports can be configured as inputs or outputs using various plug-in modules.
Input Modules: The 1780A/1780AT Mic/Line Input modules and 1781A/1781AT Programmable Input modules accept mic or line level signals through diverse connector interfaces. The 1781A/1781AT modules offer electronically balanced inputs, adjustable gain, high and low pass filters, RFI protection, 48V phantom power, two levels of muting, and remote volume control.
Output Modules: The 1783 Line Output module allows interfacing with other professional equipment.
Linking Capability: Multiple mainframes can be dynamically linked using the LINK IN/LINK OUT phono connectors, expanding the system to control up to twelve input channels or more.
External Signal Processing: PREAMP OUT and AMP IN phono connectors allow for the insertion of external equalizers or other signal processing devices.
Auxiliary Output: The AUX OUT phono connector can drive a second amplifier or a tape recorder.
Battery Backup: The system can be powered from a battery input connector for auxiliary operation or standby switchover, requiring two ±48V DC battery power sources.
Remote Muting and Tone Generation: A seven-lug screw terminal connector provides access for external switches to operate the system's mute and tone generator.
Rack Mountable: The unit can be shelf or rack mounted, with provisions for airflow and temperature management.

Maintenance Features:

Easy Access: A trap-door on the top panel provides easy access to the internal components for maintenance.
Voltage Selection: The power transformer's primary line voltage can be re-strapped for 100, 200, 220, or 240 Vac operation, with clear instructions and fuse selection charts provided.
Fuse Protection: Output and AC line fuses protect against excessive current, with specific replacement guidelines.
Power Amplifier Bias and DC Offset Adjustment: Detailed procedures are provided for adjusting the power amplifier bias and DC offset using a DC voltmeter, ensuring optimal performance. These adjustments require accessing internal trimpots (SVR101 and SVR102).
Parts Ordering: A comprehensive parts list is included, with instructions for ordering replacement components by designator and part number.
Factory Service and Technical Assistance: Contact information for Altec Lansing Customer Service/Repair and Technical Assistance is provided for factory service and applications support. Users are warned that unauthorized repairs will void the warranty.