The Altec 1591A solid-state compressor-amplifier is one of the most impressive audio devices to emerge from ALTEC’s quality engineering. It excels in boosting average signal levels without exceeding the equipment’s dynamic range limits, effectively addressing the issue of varying speech levels in public address systems.
At the same time, it provides automatic gain control. Its ability to enhance weak signal inputs while reducing overly strong ones gives speakers and lecturers greater freedom around the microphone. Easy to install and operate, this versatile unit for controlling and amplifying signal levels adds a touch of refinement to even the most advanced sound systems.
The Altec 1591A compressor-amplifier can work with both microphone and line-level sources, delivering outputs of up to +18 dBm into 150- or 600-Ohm loads. It has a frequency response of ±1.0 dB, ranging from 20 to 20,000 Hz. A standout feature is its capability to mix high- and low-level signals simultaneously, with each input having its own gain control.
It offers up to 35 dB of gain reduction, with compression ratios of 5:1 or 10:1, selectable via a front-panel switch. Thresholds can be set at 0 dBm or +8 dBm, and the compressor function can be switched off for linear amplification. The unit provides a fast release time of 0.5 seconds, along with a slower 1.5-second release option, which is more suitable for music. A direct-reading meter on the front panel conveniently displays the level of program-material compression.
The rear panel includes octal sockets for connecting Altec’s 1578A or 1588A microphone preamplifiers, as well as the Altec 15095 transformer, which is essential for isolating the Altec 1591A when operating with line-level inputs.
The Altec 1591A also supports the Altec 1591A equalised phono amplifier, which can be plugged into the low-level input socket for use with magnetic phonograph pickups.
This compressor-amplifier can be powered by either 120 or 240V AC (50/60 Hz) or 12 or 24V DC sources. A permanent connection between the AC and DC sources ensures an immediate and silent transfer to DC in case of an AC power failure, preventing any interruption in the program material.
With its versatility and superior performance, the solid-state Altec 1591A compressor-amplifier offers that essential “final touch” to high-end audio reproduction systems or installed sound setups.
Features
- All solid-state design; compact, rugged construction
- Compression and/or mixing of high- or low-level inputs with separate gain controls
- Enables announce-mike channel to override program-material
- Plug-in accessories:
- Microphone preamplifier
- Equalized phono preamplifier
- Transformer-isolated preamplifier
- AC or DC (battery) powered
- Operates from microphone level or line level signal sources
- Up to 35 dB of signal compression
- Compression “defeat” for linear amplification
- Direct-reading compression meter
- Selectable compression ratios: 5 to 1 or 10 to 1
- Selectable compression thresholds of zero dBm and +8 dBm
