API 500 series 527 mono tracking compressor. The API 527 is a fully discrete compressor incorporating the patented thrust circuit from the API 2500 stereo compressor and classic API 2520 op amps. The 527 features separate variable controls for attack, release, threshold, ratio, and output.There is also a fast forward/feedback switch, hard or soft knee switch, and an excellent led meter.
The 527 is very responsive and intuitive to set. Great on vocals, drums, guitar, synthesizers and many other sources. Clear, punchy and effective. Stereo linkable if you have 2 . +4 balanced I/O. Made in USA