This is a collection in pictures. I'll add text later.
Ron Mancini, TI
AD536 Absolute Value
Comparator-based peak detector
Comparator-based peak detector with NPN Boost
A diode simulator
Current rectifier and frequency doubler
The discontinued GAP-01 as a rectifier.
A two-color overload indicator
A peak flasher. Note the pinout error on the bottom TL074.
A log peak detector. Two channels shown. Crazynightowl may recognize this one.
The AD823 op amp used as a rectifier
AD823 rectifier output
D-R Compressor Shunt rectifier
An early dbx rms detector from the patent application.
A dbx rms detector using the CA3083.
Stephen Woodward, rms detector with differential input
dbx 902 rms using transistor array
bcarso symmetrical rectifier
Graeme symmetrical rectifier
Note: The above rectifier circuit has been attributed to SSL by Rod Elliot but I first saw it in the 1973 edition of "Applications of Operational Amplifiers," Jerald Graeme, Burrr Brown. It is used in the SSL Phase Meter.
Boss SG-1 Rectifier
“Logic will get you from A to B. Imagination will take you everywhere.”