Collins 26-1U compressor

Another favorite of mine: the Collins 26-1U.
here is the schematic if you have one of these: http://www.waltzingbear.com/Schematics/Misc/Collins_26U1.htm

Also, this thing uses the classic 6386 vari-mu tube, like the GE unilevel, gates sta-level, fairchild 660/670, and other modern thingies from pendulum audio and a few others. I love the 6386 based compressors a lot. They just do something none of my other comps will do. The UTC transformers in the 261U sound amazing just running through them, and this box has found its way onto almost every record I have mixed in the last 5+ years.  Highly recommended. They seem to be getting really expensive lately, so if you have the money: now is the time.