Symetrix 528 – Key Specifications

General

• Type: Single-channel analog voice processor / channel strip

• Form factor: 1U, 19-inch rackmount

• Application: Broadcast, voice-over, studio, live sound

Signal Path / Processing Blocks

1. Microphone Preamplifier

   • Balanced XLR mic input

   • Switchable +48 V phantom power

   • Gain range: approx. 25–50 dB

   • Very low noise design

2. De-Esser

   • Frequency selectable approx. 800 Hz – 8 kHz

   • Adjustable depth (up to ~20 dB attenuation)

   • Designed for vocal sibilance control

3. Compressor / Limiter

   • Ratio range: approx. 1:1 to 20:1

   • Adjustable threshold

   • Program-dependent attack and release (no manual timing controls)

   • Can operate as soft limiter at high ratios

4. Downward Expander / Noise Gate

   • Adjustable threshold

   • Reduces room noise and mic bleed between speech

   • Integrated with compressor section

5. 3-Band Parametric Equalizer

   • Low band: ~16 Hz – 500 Hz

   • Mid band: ~200 Hz – 6.3 kHz

   • High band: ~680 Hz – 22 kHz

   • Boost/Cut: approx. ±15 dB

   • Variable bandwidth (Q) per band

6. Output Section

   • Balanced line-level output

   • Output gain trim

   • LED metering for level and gain reduction

   • Clip indicator (~3 dB before clipping)

I/O and Routing

• Balanced XLR mic input

• Balanced line input

• Balanced main output

• Rear-panel patch points / barrier strip for:

  • Preamp out

  • De-esser out

  • Dynamics insert

  • EQ out

  • Sidechain access (advanced broadcast setups)

Audio Performance (Typical)

• Frequency response: ~20 Hz – 20 kHz (flat, EQ bypassed)

• THD: <0.05%

• Noise floor: Broadcast-grade, very low

• Headroom: High analog headroom suitable for announcer mics

Power / Physical

• Power: 115 VAC or 230 VAC (model dependent)

• Consumption: ~15 W

• Weight: ~7–8 lb

Practical Notes

• The original 528 is fully analog and highly flexible 

• Widely respected for natural vocal sound

• Patch points make it ideal for complex studio routing.