From Presonus:

8-channel Compressor/Limiter/Gate

One of our all-time most popular products, the ACP88 delivers the classic analog compression that helped establish PreSonus as a leading signal-processor manufacturer. With eight independent, linkable, full-featured compressor/limiters and gates, each of which can operate at either +4 dBu or -10 dBV, the ACP88 can solve a host of thorny studio and live-sound problems. Each channel can be independently bypassed so you can audition signals with and without processing. And you can see at a glance what’s going on, thanks to a six-segment LED gain-reduction meter and pair of LEDs that indicate gate position (open/closed) and compression threshold (above/below).

Features

• Full-featured analog compressor/limiter
  • Attack, Release, Ratio, Threshold, and (makeup) Gain controls
  • Auto Attack button
  • Soft/hard knee switch
  • Sidechain send/return
  • 6-segment LED gain-reduction meter
• Full-featured gate
  • Sidechain/key insert send/return
  • Attack, Release, and Threshold controls
  • Gate-range switch
• Bypass switch
• Channel Link button (can link multiple channels)
• +4 dBu/-10 dBV operating-level switch
• Input/Output (For each channel (x 8 channels):
  • 1 balanced ¼” TRS line input
  • 1 balanced ¼” TRS line output
  • 1 unbalanced TRS ¼” compressor sidechain send-return
  • 1 unbalanced TRS ¼” gate sidechain/key insert send-return
• Physical
  • 2U 19” rack-mountable, rugged steel chassis
  • Internal power supply with standard IEC connector