British Valve Limiter Compressors

[tardishead]

There is plenty of info on Collins, Gates, RCA, ALtec and other US made vari mu limiters. What about British stuff. I have read mentions of EMI, BBC, PYE and STC valve limiters out there but never seen a schematic. Or are they just copies of the US units? Is there anyone out there who might have some more info?

 

[emrr]

Dennis has that cool EMI unit.  No luck getting them to give up the info. 

I've seen some one-off Pye tube limiters.  Luck is there aren't too many tricks or strange implementations, and you can count on them mostly being twists on the same themes.  You just have to actually find one to rev/eng.

Sheer scale of population has a lot to do with it.  The stuff you mention only had so many possible end destinations, most being large plants, and few small independent operations.  Certainly as compared to the US.  Large plants always trash obsoleted equipment, and little escapes the grim reaper.  Small independents keeping stuff forever, or selling it on, account for the majority of US vintage equipment knowledge.  It's certainly not because of NBC/CBS/ABC's disposal and archiving habits. 

There are various pieces if in-house NBC equipment that almost everyone in the US listened to, yet nearly none have survived.  It's hard to even learn of their existence, let alone find info or extant examples.  In the US, I've seen easily 30 custom tube limiters built by radio stations for their own use.  Some are straight clones, others are unique, some are based on 1930's-1940's example circuits published in the trade journals. 

 

[lassoharp]

Know if there were any relevant British trade publications form the earlier eras?  Might be worth attempting to hunt some down. Maybe some specific journal for BBC?

 

[emrr]

I'm not aware of any, but I haven't looked.  Scouring the RDH references may yield some titles.  The problem there may be like the problem here; the RCA and WE in-house trade mags sell close to $100 an issue when they surface.  I would imagine the same for any Beeb materials. 

There is the Beeb equipment archive online; some stuff there.  Haven't looked recently. 

 

[tardishead]

What about European - German etc. Early stuff.

As for EMI RS limiter - what valves was it using?? Or does nobody know?

 

[strangeandbouncy]

Decca limiter is supposed to be the bomb . . .

 

[tardishead]

I bet but no one is willing to share info if they have it. I think I might be able to borrow an old PYE limiter. If so I will reverse engineer it.

 

[detonator]

Joemeek and his optical processing is the only thing that comes up to me when I hear about British compression.

 

[tardishead]

In an interview Joe Meek talks about his BBC limiter being the best one he owns..

I wonder how old that would be - probably 40s 50s.

 

[detonator]

In an interview Joe Meek talks about his BBC limiter being the best one he owns. I wonder how old that would be - probably 40s 50s.

Don't know for sure. His tape compression tricks came from the late fifties and early sixties. I guess that it should be around the same time.

The Joemeek company it self has been run by Ted Fletcher, who has worked a couple of years as an engineer for Meek. They’re responsible for getting optical compression well known to all of us. Meek himself was a paranoia addict, accusing Fletcher of stealing designs. But he left a hell of a legacy without knowing it.

 

[Rob Flinn]

What about European - German etc. Early stuff.

As for EMI RS limiter - what valves was it using?? Or does nobody know?

Germany had the U73 & also the Rohde & Schwartz limiter

 

[squib]

and don't forget some of the outstanding AWA units made in Australia in the 1950s, early 60s. There are around three common models of tube vari mu limiters made by AWA and whilst they naturally share some design concepts with other manufacturers vari mus they also have some unique aspects and generally excellent technical performance. Refurbished, re-tubed, balanced and if desired, variable attack and release mods added they rock!

 

[Michael Tibes]

What about European - German etc. Early stuff.

As for EMI RS limiter - what valves was it using?? Or does nobody know?

Germany had the U73 & also the Rohde & Schwartz limiter

-which are well documented in terms of schematics and descriptions. If it's not on Kubis site, I might have it. There are no detailed infos on trafo windings of course. Anyway, I have both and on their own they are somewhat special, not like a universal compressor we think of nowadays. The thinking in Germany might have been less 'creative' and more 'technical' in a sense, they lack controls in nowadys sense. I still haven't tried the U73 with the varicom (an extra control unit), it might become a different beast with it.

Michael

 

[emrr]

The thinking in Germany might have been less 'creative' and more 'technical' in a sense, they lack controls in nowadys sense.

True of everyone's production at the time, not specific to BRD.  Popular usage today hinges on how well these old devices act badly when pushed well past their design intent.  We would hardly recognize that which was considered sufficient limiting action back then. 

 

[mrclunk]

What about Marconi? 
They must of made some groovy limiters.