Symetrix 528E Microphone Processor

This complete analog channel strip performs six separate functions: microphone preamplification, de-essing (sibilance removal), compression/limiting, downward expansion, parametric EQ, and voice symmetry alignment.

The processing power of an entire recording studio signal chain in a single Symetrix 528E Voice Processor. All six processes may be used simultaneously. Although we call the 528E a "Voice Processor", it is perfectly suitable for any mic- or line-level source. Revered as the choice for broadcast voices and known as the classic "one channel console" by recording studios, the 528E delivers all the control you need, without the cost or complication of separate units. Each function has a full complement of controls in an easy-to-use layout. The 528E works with any professional microphone.

• Mic preamp gain is variable up to 60 dB. 48 volt phantom power for condenser mics. A switchable 15 dB pad reduces gain in front of the mic preamp preventing distortion in super-close micing situations.
• The de-esser senses and regulates selectable high frequencies to reduce or eliminate annoying sibilance and "lip smacking."
• Program-controlled Integrated Dynamics Processing (IDP) techniques combine the best attributes of compressor/limiters and downward expanders. The compressor/limiter maintains uniform levels while the downward expander eliminates "pumping," "breathing," and noise build up.
• The three band parametric EQ performs both creative enhancement and corrective (eliminating resonances and interference) operations, with bandwidth variable from 0.3 octave to 4 octaves, 15 dB boost/cut, and overlapping frequency ranges.
• The Voice Symmetry switch corrects for excessive positive or negative signal peaks of the human voice.
• Separate LED meters display mic/input gain and gain reduction, for quick and accurate adjustment of dynamics functions.
• A unique "leap frog" topology minimizes the number of amplifiers in the signal path while ensuring that each frequency band interacts with its neighbor in a desirable and musical fashion.
• The program controlled dynamic range processor responds quickly to transients, and gently to smaller level changes.

A front panel switch selects between microphone or line input. Both are transformerless and with radio frequency interference (RFI) filters.

Performance Data

Input/Output
Controls and Switches: Mic Gain, Phantom Power, Mic/Line
Mic and Line Input Connectors: XLR-female (2)
Clip LED: Lights at +17 dBu output level from mic preamp or line input amplifier
Microphone Input Type: Balanced Transformerless, Low Impedance
Phantom Power (DIN 45 596): +48V, nominal
Microphone Preamp Gain: 22 to 60 dB (pad out), 7 to 45 dB (pad in)
Microphone Input Maximum Input Level: -3 dBu (pad out)
Equivalent Input Noise (EIN): -126 dBV (150-0 Ohm source, 20 Hz to 20 kHz)
THD + Noise (Preamp only): 0.05% (2 kHz, 50 dB gain, +17 dBu output)
Mic Preamp CMRR: > 50 dB (40 dB gain, 20 Hz to 20 kHz)
Line Input Type and Impedance: 10k Ohm Transformerless Balanced Bridging
Line Input Maximum Input Level: +24 dBu
Line Input Nominal Input Level: +4 dBu
Line Input CMRR: > 50 dB (0 dBu, 20 Hz to 20 kHz)

Parametric Equalizer
Type: Three-band Parametric Equalizer
Bands: Low: 16 to 500 Hz, Mid: 160 to 6300 Hz,
High: 680 Hz to 22 kHz
Peak/Dip Bandwidth: 0.3 to 4 octaves, measured at maximum boost
Maximum Boost/Cut: +/- 15 dB

Metering
Type: Multi-segment LED bar graph
Output Level: -20 to +3 VU (0 VU = +4 dBu), VU calibrated, peak responding
Gain Reduction: Separate displays for: de-esser, downward expander, and compressor 0 to 20 dB per display

Overall Performance Data
Frequency Response: 20 Hz to 20 kHz (+0, -0.5 dB), EQ out, compressor out, downward expander out, de-esser out
THD + Noise: 0.05%, 20 Hz to 20 kHz, +4 dBm output
Noise Floor: Better than -89 dBu, 20 Hz to 20 kHz

Architects & Engineers Specifications

The voice processor shall be capable of all signal processing functions commonly found on a mixing console input channel, including microphone signal preamplification, line input buffering, simultaneous de-essing, downward expansion, compression/limiting, and parametric equalization.

The unit shall have a low-noise, low distortion microphone preamplifier with variable gain (22 dB to 60 dB) and switchable (on/off) +48V phantom power. A 15 dB pad shall be provided to accommodate high output microphone signals. A balanced-bridging line input suitable for +4 dBu input signals shall also be provided along with a switch to select either the microphone or line inputs.

The voice processor shall have an integral de-esser which shall offer up to 20 db of attenuation within a manually sweepable frequency range of 800 Hz to 8 kHz. There shall be front panel controls for range, frequency, and a bypass switch.

The dynamics processing section shall contain an interactive compressor/limiter and downward expander. There shall be front panel controls for compression ratio (1:1 to 10:1), compressor threshold (-50 dBm to +20 dBm), expander threshold (-30 dBm to 0 dBm), and a bypass switch.

There shall be a three-band parametric equalizer. Each band shall have ±15 dB maximum boost/cut, and continuously variable bandwidth (0.3 octaves to 4 octaves). The equalizer bands shall have substantially overlapping frequency ranges, with a combined range of 16 Hz to 22 kHz. There shall be a front panel bypass switch.

The voice processor shall be equipped with the following LED displays: An eight-segment LED display shall be provided for monitoring the overall output level, six-segment displays for monitoring the de-esser, compressor/limiter, and downward expander. All displays shall be independent. There shall also be a single LED clip indicator to indicate clipping within either of the input preamplifiers or buffers.

The microphone input shall be an active balanced bridging design terminated with 3-pin XLR-female connector (AES/IEC standard wiring). The microphone preamp shall be capable of an equivalent input noise specification of at least -126 dBu (150-Ohm source, 60 dB gain, 20 Hz to 20 kHz). The line input shall be a balanced, transformerless design using a 3-pin XLR-female connector (AES/IEC standard wiring). All input circuitry shall incorporate RFI filters of the LC low-pass type.

The output shall be an active balanced design terminated with a 3-pin XLR-male connector (AES/IEC standard wiring). The output signal level shall be switchable to accommodate subsequent line or microphone inputs. The output section shall provide a switchable phase rotator for the purpose of improving the asymmetry of speech waveforms.

Access to the dynamics processing sidechain shall be provided via a ¼" TRS jack. Access to the interstage connections between all processing sections (mic/line preamp, de-esser, compressor/limiter/downward expander, equalizer, output stage) shall be provided via half-normalled tip-ring-sleeve (TRS) jacks.

The voice processor shall be capable of operating by means of its own built-in power supply connected to 115 VAC nominal (105 to 130 VAC), 50/60 Hz or 230 VAC nominal (207 to 253 VAC ), 50 Hz.

The unit shall be a Symetrix Incorporated model 528E Voice Processor.

• Single rack space classic analog channel strip. Applications: Broadcast, Studio, Podcasting, Installed Sound.
• Add warmth and color to your digital broadcasts & recordings.
• World renowned Symetrix sound quality, reliability and performance.
• Six processes in one box: Mic Preamp, De-esser, Downward Expander, Compressor, 3-band EQ, and Voice Symmetry.
• Rear panel patch points allow re-ordering of processes or external effects inserts.