Purple Audio MC77 Limiter

The Purple Audio MC77 Limiter recreates the audio circuitry of the revision E 1176, using modern components matched to the original. Introduced in 1997, Purple Audio started making the MC76, an 1176 type compressor based on the D & E version units. The MC77 builds upon this legacy, adding new features that were lacking from the original.

Thousands of units later, Purple Audio maintains high parts and build quality, using components designed to last decades. Features like a toroidal power transformer, the best interlocking switches on the market, and conductive plastic potentiometers ensure the MC77 is built for longevity.

Inherited from the MC76

• Discrete Transistor Audio Path Electronics
• Single Element Class A Output Amplifier
• Transformer Balanced XLR Inputs and Outputs
• Zener Shunt Regulated Audio Power Supply
• Compression Ratios: 4:1, 8:1, 12:1, and 20:1
• Fast Attack Time: 20 to 800 microseconds
• Release Time: 50 milliseconds to 1.1 second
• Gain of 45dB (full gain with no limiting)
• Ruggedized Design: PCB stiffener, chassis mounts
• Purple Anodized Aluminum Front Panel
• 3 Year Warranty*

New on the MC77

• True Bypass via sealed relay with front panel switch
• Improved stereo linking with front panel switch
• Sidechain insert loop or key input with front panel switch
• Buffered VU meter can monitor input or output level at +4dBu
• LED meter lights that don’t burn out
• Heavy gauge black cold rolled steel enclosure
• 155v/230v operation switchable from rear panel

The MC77 should be fitted with a 1/4A slow-blow fuse at 110V, and a 1/8A slow-blow fuse at 220V. These fuses are available from Mouser or Digikey in the US.

• Discrete Transistor Audio Path Electronics
• Single Element Class A Output Amplifier
• Transformer Balanced XLR Inputs and Outputs
• Zener Shunt Regulated Audio Power Supply
• Compression Ratios: 4:1, 8:1, 12:1, and 20:1
• Fast Attack Time: 20 to 800 microseconds
• Release Time: 50 milliseconds to 1.1 second
• Gain: 45dB (full gain with no limiting)
• Ruggedized Design: PCB stiffener, chassis mounts
• Purple Anodized Aluminum Front Panel
• True Bypass via sealed relay with front panel switch
• Improved stereo linking with front panel switch
• Sidechain insert loop or key input with front panel switch
• Buffered VU meter can monitor input or output level at +4dBu
• LED meter lights that don’t burn out
• Heavy gauge black cold rolled steel enclosure
• 155v/230v operation switchable from rear panel