Spectra 1964 Model C610

The Spectra 1964 Model C610 Complimiter. True to the original, the C610 still utilized the unchanged and still unmatched 601 Compressor/Limiter circuit, as well as a 101 amplifier for make-up gain. The improvements we've made include XLR and Phoenix I/O, highest quality input/output transformers, selectable input padding, buffered true VU metering, and multi-stage overload indication.

The Model C610 "COMPLIMITER" is a compressor/limiter system with performance both measurably and audibly discernible as "beyond the state of the art". The completely self-contained unit is compatible with the audio equipment and accessories used in professional recording, broadcasting, motion picture and soundreinforcement industries. Because of extremely low noise characteristics of the design, the system has a very low input level threshold of -40 dBu, thus providing the greatest input sensitivity and compatibility with the widest range of system levels available on the professional audio market. Depending on the program content, the Model C610 "COMPLIMITER" will accept an input signal from -50 dBu to -40 dBu just prior to beginning compression, as well as standard line level input signal.

Control functions are provided on the front panel for input level threshold, continuously variable compression slope (ratio), release time, selectable pad (10 and 20 dB), and output level. Visual LED indicators for peak limiting and system overload are provided, in addition to Vu meter monitoring.

Input Impedance: 600 Ohms

Output Impedance: 2.5k Ohms

Input Pad: Position 1: No Pad, Position 2: +4 dBu nominal input, Position 3: +22 dBu nominal input

Maximum Gain: 56dB

Threshold attack level: -40 dBm

Maximum Output: +18dBu

THD: Less than .01% @ 30Hz-20KHz, at +16 dBm, up to 30dB compression, dependent on release setting

Signal/Noise: Better than 80dB below +4dBm output, with -40 dBm input, 20Hz to 20kHz

Frequency Response: +/- 0.1dB 20Hz-40KHz

Compression/Limiting Ratio: Continuously variable from 1.1:1 to 100:1

Attack time: 100 nanoseconds to 1.2 milliseconds, automatically variable.

Release Time: Continuously variable from 50 milliseconds to more than 10 seconds