ITHertz wrote:A little history question for an article I'm working on - who invented the Diode Bridge compressor? I was under the impression that it was Rupert Neve:
The earliest diode-bridge audio compressor I'm aware of was the Telefunken one, the U13, which was developed for German broadcasters. And it used valve rectifiers as the active devices. Clever people, them Germans...
Neve's 2254 from the very late 1960s is obviously the best known implementation of the idea, but Rupert Neve didn't actually design it himself.
It was one of his employees, an ex-BBC engineer called David Rees who borrowed Telefunken's idea -- possibly after coming across it somewhere in his broadcast career -- and redeveloped it using solid-state circuitry.
I don't believe it was designed independently. Telefunken's concept would have been known about. But I imagine Rees did a lot of original R&D to get it to work with solid-state rectifiers. Allegedly, his first prototype was built using nails hammered into wood as a DIY turret board ... which is believable... although standard turret board was readily available at the time and would probably have been a lot easier to use! So I take that with a pinch of salt.
Rees' first working model was actually issued with the module number 2253 -- infamous the 2254 came a bit later and was a more 'developed' version -- although it evolved further still over the years, with the 2254A, and then later the 2254E which had a faster attack time I think.
There have been lots of variations on the theme subsequently. Neve themselves went on to make the much more versatile and lovely-sounding 33609, beloved of BBC TV Sound Supervisors (amongst many others), and the current AMS Neve company still makes versions of the 2254 and 33609.
But many other manufacturers have taken the core design and either copied it more or less as is, or updated it to remove some of the transformers and improve transformers. Some have re-developed the concept using different types of diode to get better performance characteristics too.
I don't know of anyone that has reverted to using valve rectifiers... but I wouldn't be surprised is some American niche manufacturer didn't offer it one day...