The 436C Compressor Amplifier is a self-powered, level-controlling amplifier with a versatility which makes it a desirable part of most audio installations. In response to a strong input signal, it will reduce gain up to 30 db auto- matically, rapidly, and quietly, without the introduction of thumps.
Link for PDF: 436C Compressor Amplifier (c1966)
https://aboutprosound.com/wp-content/uploads/2022/10/Altec-436C.pdf
