175b Compressor

The UA175b was one of the finest vari-mu compressors ever built.  The 175 was one of Universal Audio’s first commercial products and they were manufactured in Hollywood above the Western Studios on Sunset.  It was designed by Bill Putnam Jr., along with several other classic pieces of audio equipment.

The 175b has a 12:1 fixed ratio, and unlike the 175a, has the attack and release controls on the front panel.  They have a naturally smooth attack and release, and many engineers prefer the 175 to many other vari-mu compressors.

The replica that i’m trying to create is using the closest components that i can find to the originals.  The original components are just too cost prohibitive fro me to acquire at this point.  All of the transformers are the Sowter recreations, and the pcb board from Drip Electronics has an identical path to the point-to-point circuitry of the original.  I’m using all Ohmite carbon comp resistors, Solen capacitors, and lots of other sonic goodies to get the same lush sound of the original.  This will be the first front panel that i will be designing from scratch.  I hope i can design something half as cool as the original.  Now if i could just figure out a way to age the components 60 years so they sound like the originals….  Here’s a few pics of the build and an original 175b: