The Retro Instruments 176 is based on a Bill Putnam classic, the UA 176. The 176 faithfully reproduces the sound of the 1960s original with new features for the modern recording studio. The Retro Instruments 176 provides one of the most desirable compression signatures in recording history.
...download audio from this thread: https://gearspace.com/board/gear-shoot-outs-sound-file-comparisons-audio-tests/699125-hardware-compressor-limiter-comparison-thread-audio-files.html Ive been able to get it pretty close to the first Manley example...and similar to the Retro 176 although the Retro has a very bright exciting upper mid...but anyway - this compressor beats every tube emulation Ive tried by a long shot...Im having to almost stop myself saying its comparable...
...one of them has an issue of some sort. But it is worth the bother. A great alternative is the Retro 176 limiting amplifier, which is being made today by Phil Moore of Retro: Retro Instruments: 176 Limiting Amplifier I've put the Retro unit along side my 175Bs and they are pretty damn close. Close enough...
...as the MJUC is, its more "inspired by" the 176, as well as a few others - a de facto RETRO 176 plugin would just be so so good