Bloo makes an LA-2a kit. It's the absolute "Dog's Bollocks" (mutts nutts). Indistinguishable from the real thing, at about 1/3rd of the price.
Bloo kits have been built by a few of the folks at the Prodigy-pro furum, linked above, 'Scenaria' is the guy to talk to.
Manley are rather protective of their stuff and do NOT allow schematics to be distributed. EveAnna has been known to step into discussions about cloning their products, or threads about sharing schematics, and put an end to it all.
Shortened version: Manley schematics: -Don't go there.
There are a number of "variable-mu" (a term which Manley actually trademarked, despite the topology being in use for 40 years prior, and the term having been in common parlance for a long time) compressors such as the Fairchild, the Pendulum, the Gates Level-Devil, and a couple of others, but they all tend to use tubes (valves) which are in short supply and/or overpriced. The old designs generally use no longer manufactured transformers as an intrinsic part of the process: the fundamental basis of the variable mu limiter is a split-polarity signal through two halves of a tube, with a transformer differentially passing the gain-controlled audio and rejecting the control voltage.
If you want vintage, the LA-2a is the easiest candidate, since you can basically buy a kit. If you must have variable mu, there's a version which infringes no copyrights, and was designed to use the 12AU7 -a tube which will be available for a long time to come: and easily obtainable transformers from radio shack. The power transformers are also readily available, and the whole thing was intended to be built, shared and enjoyed without pissing off manufacturers...
Here is the link:
http://www.conditionedresponse.com/DIY/C5/index.htmlIf you pursue the Manley thing too far, you might get a stern response from a certain lady who's generally understood to become rather anoyed by people sharing her schematics...
Keith
