Audio Historians - REDD/RCA/Langevin/RFT Lorentz/WSW

[Winston OBoogie]

Thanks for all the info Winston,  it was a joy to read over the weekend.

Cheers my man 

 

[matriachamplification]

This is not information I can easily graze over. We are excited to begin disecting this and connecting it to our CTC REDD Card Build. Good times! Thanks all! Winston thanks!

 

[emrr]

I did say they were over engineered pieces of equipment and that a lot of what was engineered into them isn't necessarily practical or useful these days... 

Um, yeah, autoformers to feed pans.  Yeah, why not?

 

[janos.hardi]

I think I was the first (and then sadly the only person) who was interested in chatting with Len Page who had started REDD back in 1955.  No-one had thought to ask him questions and, shortly after getting insights from him, he sadly passed away.

So much missed opportunities there... Off topic but I remember in my high school times our old teacher (war time radio guy) being laughed at, noone cared about his stories on fixing mil tube radios on the plane over the front lines etc. I also remember at my first job I had to operate a monster steam engine oil transfer pump built in 1945 - it has never been turned off since the 50s because noone knew how to fix it (this was in the 90s, I'm sure its been retired by now). Anyhow, thanks for sharing these details!

 

[emrr]

Haha   
In its defense, it is at least one less winding than a transformer! 


Honestly, I've never given it much thought as to why the need to step up voltage there.  Maybe the clue is in the ratio?  200 - 400 gives a 1.414V bump which is 3dB, the loss at pan centre but?
     

In America I’m only aware of Langevin and Daven ladder pan pots, I’ve seen a handful of Langevin but never a Daven.  These were not uses in any production console.  Only the Altec 250 SU and T3 even had LCR positions, all others at best are dual mono LR.  The pan pots would be connected to C with expected additional losses.  If, like consoles with some EQ channels but not all, there would be fixed pads to match the pan or EQ channel losses.  I have not seen a case with any step-up, passive or active.  There is little/no documentation of any of the major studios custom consoles, and I cannot identify the first custom passive mix console to have a significant number of pan channels available.  It sounds just as common here that pans were made with parallel ladder or T attenuators connected with a gear system.

 

[gridcurrent]

on the subject of pan-pots, apologies for the sidetrack:
installed a few of the Altec slider type pan-pots in custom consoles in the early 70's.
reviewed Langevin AM4 console literature, could find no mention of panning,
yet had one when restoring an AM4 some time back.
no clear evidence of pan-pots in the block diagram of the Porterfield console at Columbia 30th.

 

[emrr]

I've also not seen many (any?) US desks from then with pans, although I believe I've seen photos of motion-picture remixing consoles with the ability. *

During mix down from 3 track to 2, this was simply a passive mixing/splitting of the centre track with both left and right buses.
True?

Yes, more likely in film consoles, all of which are little documented and long since destroyed. 

The only thing I've seen is the Altec 250 SU/T3 method which adds a set of intermediate L C R bus isolation amps, with C feeding back to both L and R iso amps through series resistance.  Center going through an additional amp compared to L and R. 

 

[matriachamplification]

Bach Auricon made some portable tube consoles for tracking diretly to film.
The Auricon Mixers had some features to maximize tracking to tape. Really interesting Tube equipment, although I have only ever read about them.

Maybe someone might find this schematic of the Auricon Sound-On-Film NR40-S4 interesting.

 

[hodad]

I've also not seen many (any?) US desks from then with pans, although I believe I've seen photos of motion-picture remixing consoles with the ability. *

And yet, apparently, the first major film to be released in stereo was Streisand's A Star is Born in 1975 (this according to a documentary on film sound called Making Waves).  What were the motion picture folks doing with those pan knobs?

 

[emrr]

And yet, apparently, the first major film to be released in stereo was Streisand's A Star is Born in 1975 (this according to a documentary on film sound called Making Waves).  What were the motion picture folks doing with those pan knobs?

Wrong AF.  Maybe by some particular standardization. 

Fantasia

https://en.wikipedia.org/wiki/Fantasound

 

[matriachamplification]

Wrong AF.  Maybe by some particular standardization. 

Fantasia

https://en.wikipedia.org/wiki/Fantasound

It was likely based on the millions invested into A Star is Born' audio. I think this is a key factor to why it is considered a "first".

 

[emrr]

They were already doing multitrack with editing on mag film in the ‘30’s.

 

[hodad]

Wrong AF.  Maybe by some particular standardization. 

Fantasia

https://en.wikipedia.org/wiki/Fantasound

It's possible they meant it was the first film released exclusively in stereo, or they were indeed just wrong.

EDIT:  It was one of the first films released in Dolby stereo--my mistake.

 

[matriachamplification]

This is where we are stuck in our storyline.

The RCA BE-1A Passive Equalizer (which we pruchased from my wife!) was apparently the inspiration for the REDD Eq of some denomination. Is there any fact to this?

Secondly, we are certain we have a picture of Dick Sweetenham holding a Tube Compressor he built while at REDD, but can find no information about it. I have just touched base with Helios about this.

Any insight into these areas?

 

[emrr]

The RCA BE-1A Passive Equalizer (which we pruchased from my wife!) was apparently the inspiration for the REDD Eq of some denomination. Is there any fact to this?

Can't be.  It's a bog-standard telephone line EQ meant for long line treble correction.  Many versions from many companies, back to the 1920's. 

 

[matriachamplification]

Can't be.  It's a bog-standard telephone line EQ meant for long line treble correction.  Many versions from many companies, back to the 1920's.

YES! When you first mentioned it to me I followed up of course in the manual.

Somewhere, somehow we read it had over 1000 possible bell curves. I think Foley console repair mentioned it. This was not what I recall in my research but Ben at Foley is a pretty knowledgable guy.

 

[matriachamplification]

I'd certainly like to see the picture of Dick Swettenham with the the compressor he supposedly built at Abbey Road. 
However, along with the over 30 modified Altecs/RS.124's in use, and before the acquisition of 16 Fairchild 660 limiters, the EMI limiter in use at Abbey Road was the RS.114

I've not seen a schematic of that particular unit, but by all accounts, it wasn't well regarded and was quite finicky to keep balanced and working correctly.
The  RS.114's (note: not RS.124's) seem to just stop being used the minute the Fairchild's arrived in the early 1960's.

Its very likely I imagined the Sweetenham Tube Compressor scenario up. I spent too much time in my head thinking about tube compression )

The RS114, good to add as a footnote.

 

[matriachamplification]

By the way, I'm starting to think that the title of this thread might better be served by a re-title such as:
"Hinson's Endless, Non-Sequitored Brain Dump"

Please stop me if you think I need help!

This is all of the most interest to me. I love history! I think everyone is enjoying the read

Any insight we welcome!

 

[gridcurrent]

the Levy brothers were responsible for a few Pultec-Altec clones. 
Audio transformers by R.J Gilson Ltd. of Wimbledom.
Of the units that came across my path, one had an interstage transformer.

 

[emrr]

emailed the Pul-Al-Tec to you John. Shows Altec transformers, but they add an interstage transformer and a driver stage for a more typical 3 tube limiter amp.