Categories
Connecticut Audio History

UPDATED: Emory Cook, Binaural Recording Pioneer

Emory Cook records Long Island Sound at Shippen Point, Stamford CT (with two mics, of course): 1954.  He is using a Modified Magnecorder.  This, and all other reproduced materials in this article are courtesy T.Fine.

***UPDATE: I’ve added a variety of links to relevant Cook-resources at the end of the piece. ***

Thanks again to contributor T.F. for providing an extensive collection of documents relating to one Emory Cook, inventor, Connecticut businessman, and pioneer of binaural sound.  There is much too much information contained within these primary source documents for me to adequately paraphrase, but here is a quick synopsis.

Cook (at left) attended MIT, briefly, in the 1930s, and received his electrical engineering degree (minor in communications) from Cornell immediately following.  After an incomplete stint at Columbia Grad he went into industry as an engineer, primarily radar and some broadcast work.  Excited by the postwar prospects of magnetic-tape recording and the general explosion of sound-recording technology of the late 1940s, Cook then began his own enterprise of designing and manufacturing sound-recording hardware which he claimed offered vastly better performance than competing  products.  This led, in short turn, to Cook Records, which issued over 140 LPs over the course of two decades.

Above: Cook’s preferred solution to the problem of creating a fully mono-compatible stereo LP disc record.  Two separate cartridges with ample spacing each track a separate groove.  The disc could therefore be played on any mono machine without issue.  Click here for further information on this forgotten technology.

Cook achieved the widest recognition for his research and development of binaural sound apparatus.  Binaural sound is a specific type of stereo (two channel synchronized) sound which specifically attempts to capture sound in a manner consistent with the hearing apparatus of an unimpaired (IE., having full use of both ears) human animal.  Stereo sound is much broader field; truly, any system in which two discrete channels are programmed and synchronized for playback on two separately-located transducers could be described as ‘stereo.’ As the past sixty years of electronic media history has played out, true Binaural sound techniques have had limited application and/or consumer appeal, but it is critical to recognize how the field of stereo sound was largely birthed by individuals such as Mr. Cook who were so taken by the attempt to recreate, electronically, the biological process of two-eared hearing and the spatial-localization that it affords.  Beginning in the early 1950s, Cook published a number of papers and articles on the subject.  I would encourage you to read them and get the story from the horse’s-mouth, as-it-were:

DOWNLOAD: Tele-Tech-5211-Emory_Cook-Recording_Binaural_Sound_on_Discs 1952: Cook explains and defends his two-cartridge stereo LP system and offers a design for an economical stereo amplifier.

DOWNLOAD: Emory_Cook-Binaural_Disks.  A more consumer-oriented essay which covers similar material as the prior.

DOWNLOAD: Emory_Cook-AIEE-530616-Binaurality.  A technical paper on binaurality delivered in 1953.  T.F comments:  “(it is) interesting how (Cooks’s) summary of past technology ignores Blumlein’s 1934 patent.”

DOWNLOAD: High_Fidelity-5410-Emory_Cook. A largely biographical piece from HIGH FIDELITY, 1954.

IN ADDITION: The Journal of the Audio Engineering Society ran an excellent essay by Cook in their very first issue, January 1953.  Since the AES depends on the sale of their previously published material for revenue, I do not think it suitable to offer that article here; you can, however, purchase it directly from them.

Above: Cook’s suggestion for creating a listening environment for Binarual audio playback.  Contemporary thinking seems to regard headphone-listening as the only suitable mechanism for Binaural playback; Cook’s advocation of loudspeakers suggests that perhaps the difference between ‘binaural’ and ‘stereo’ need not be quite so rigid.  T.F. comments: “Cook’s explaination of Binaural…is somewhat different from the 1930’s theories of Alan Blumlein. Cook always assumed speakers, and also the right triangle of two speakers and a listener in the center. “

Cook spent considerable time and energy traveling the world to capture sound-events using the specialized equipment that he developed.  Like many early audio pioneers, he was greatly interested in the power of sound and sound-recording itself; musical recording was an important part, but only a part, of what he saw as a world of exciting sounds to capture and make available to consumers through recorded media.

Above: one of his less high-brow offerings.  Click here for liner notes: COOK01071_Burlesque.

Above: a more concise summation of the technical recordist I have not seen.  My $.02: I can’t wholly disagree with what Cook states here, but perhaps it is wiser to recognize that his conception of a recording engineer is one of many valid approaches to that field of endeavor.  Perhaps in 1953 this was tougher to see.  It’s certainly not irrelevant in our current moment, though; Cook’s viewpoint reminds me very much of contemporary recording great Steve Albini, who’s extreme preference for documentary-style production has led to some great (Nirvana, Palace) and not-so-great (Jarvis Cocker) albums.  Sometimes it’s the right move, sometimes it ain’t.

Cook remained very active in audio production and technical work at least into the 1970s; above, an image of his factory circa 1970.  Cook Laboratories offered a range of services including a recording studio, cassette and record duplication and stamping, A/V production services, and specialized equipment manufacture.

For a fascinating view inside the above-depicted plant, click below to download their circa 1970 catalog of services.

DOWNLOAD: Cook_Laboratories-1960s_brochure

There is a ton of other information online concerning Cook; here are some good places to start.   Cook passed in 2002 (click here for his obituary as published by the AES) and the catalog of recordings that he controlled is now owned and archived by the Smithsonian.  In fact, you can purchase the ‘Burlesque’ recording depicted above from them.  Cook’s Wikipedia page was apparently created with input from a former employee; if anyone out there worked for Cook at his plant in CT, please drop us a line.   I also welcome any substantiated corrections to this piece.  And I look forward to a heated discussion of the merits and/or fallacies of ‘binaural sound’ in the comments section.

Thanks yet again to T.F. for making these rare archival materials available to all.  For those of you unacquainted with T.F. and his rather unique perspective on the history and development of commercial stereo-sound recording, please click here.  

Categories
Custom Fabrication

Marantz 7 Phono Pre/ Passive Line Preamp

Above: a  Marantz 7 stereo phono stage built for stand-alone use.  See this link for an earlier build of this same circuit, along with an explanation of exactly wtf a phono preamp is (for my 7 or 8 non-technical readers).

The major difference with this build is that I included a 2nd set of (passive) inputs and a volume pot.  This is to allow the user to connect both a phonograph and a 2nd line-level source, select a listening source, and control overall volume level ahead of a stereo power amp.  I also used a tube rectifier and a choke this time.  The piece sounds fantastic.

Stereo phono preamps are fairly time-consuming to build, and small differences in layout can have dramatic effect on the overall performance.  Here are a few snapshots of the process.

Hammond steel chassis, punched-out using Greenlee hand-punches

The underside of the unit following mechanical assembly

Initial wiring.  I always start with the ‘no-brainer,’ rote wiring tasks:  First, the 120AC wiring.  Followed by the B+ supply.  Followed by the Filament supply (if any; here you see the DC filament supply constructed at the left of the turrett board).  Finally, any passive audio-control wiring (the switch, pot, and Belden cable on the left). I wire up each one of these sub-assemblies and test each one; having 100% confidence that all this stuff is functioning properly makes it a lot easier to troubleshoot and vague performance issues once the piece has been fully wired.

…and done.  It’s hard to see how many components are mounted on the tube sockets, but trust me, it’s dense.  It never ceases to amaze (annoy) me how complex phono pres end up being.  The schematics look so simple!

Categories
Microphones

eBay Alert: Lot of very rare Capps Condensor mics plus Altec ‘lipstick’ pair ending soon

Ending very shortly on eBay: a pair of 1950s Capps Condensor mics PLUS a pair of Altec Lipsticks (no power supplies).  Current price for the pile:  $231.  Caveat emptor, certainly, but for that price yr doin great if even one of ’em works.  I am so, so tempted.    Click here for the auction.  And click here for some period info on the very obscure Capps condensors.

Categories
Connecticut Audio History Pro Audio Archive

Excellent Article on Larry Scully and the Variable-Pitch Lathe c. 1956

Download a six-page article from HIGH FIDELITY 1956 concerning the history of the Scully corporation of Bridgeport Connecticut, including an explanation of the significance of the variable-pitch Scully lathe.

DOWNLOAD: High_Fidelity-5612-Scully_Sm

At left: Larry Scully circa 1956.  Thanks to reader TF for this very interesting piece.  As I have mentioned before, I drive by the old Scully factory nearly every day on my way to work at Gold Coast Recorders.  I had been hoping to uncover some history of this once-great Bridgeport institution and this article certainly sheds some light.  Some interesting bits from the article: in the 30s, Scully briefly ventured into the manufacture of P.A. equipment.  And beer coolers.  Also of note: the price of a Scully lathe in today’s dollars?  $72,000.

Previous Scully Coverage on P S dot com:

The Plant

The Model 601 Lathe

Some very neglected Scully 280s

Categories
Uncategorized

Three interesting Hi Fi Amps circa 1948

Download a three-page article from the September 1948 issue of RADIO ELECTRONICS on the subject of ‘Three Straightforward Amplifiers.”  Author is John Straede.  Schematics ETC are all included in the download.

DOWNLOAD: Three1948Amps

Above, the most interesting of the bunch: a single-ended 6L6 amp which uses fixed bias for the output stage.  I have never seen a fixed-bias SE power amp.  Seems like this could yield some unique overdriven textures for guitar applications.  Worth a look.

Above, the 13-watt 6V6 PP unit.  A couple of things to note: the input stage uses a 6U6 pentode.  I have never come across a 6U6.  Anyone use one of these?  Also: the 6U6 stage uses ‘Grid Leak Bias,’ in which the cathode is at ground potential and yet no DC bias is used on the grid.  I have never tried this type of bias.  Anyone?  Is it worth trying? What are the benefits/liabilities of grid-leak bias?

 

Categories
Uncategorized

MXL R40 Ribbon Mics are back for $69.99 at M F dot com

I continue to get a lot of readers here drawn to my earlier post on the MXL R40 ribbon mic.  Click here to read that earlier post.  In that article I describe replacing the stock transformer with an inexpensive Edcor unit and getting very good results.  Anyhow, shortly after i wrote that piece, the price of the MXL R40 shot up dramatically – to around $120.  Well I guess they couldn’t move ’em, cos they are back for $69.99.  A great deal IMO.  Click here to pick one up.

Categories
Technical

1961: Five Things

From the 1961 Langevin Catalog, which unfortunately I cannot upload due to massive file size.  Anyone know of a reliable, free way to reduce PDF size?

 

 

 

 

Categories
Altec Technical

Novel Vacuum Tube / Diode Compressor: 1950

Download a short piece from RADIO-ELECTRONICS, 1950, on the subject of a DIY audio-compressor:

DOWNLOAD: DiodeCompressor1950

This promises to be an interesting unit.  It’s designed (like a Shure Level-Loc) for Mic-Level-In, Mic-Level-Out, but that could pretty easily be changed for balanced-line operation by omitting the first 12AT7 stage and using a modest step-up transformer (maybe 1:3 or 1:5) going into the input level pot, and then adding another output stage and output transformer.  (Since 1/2 of the 2nd AT7 is unused, I am thinking: eliminate one of the 12AT7s entirely, build this circuit minus the first stage using one 12AT7, and then add the output stage from the Altec 1566).  The unit promises to add distortion, and there is some sort of low-pass network before the 3rd grid that will also need some sort of variable components added in order to control the quality of that distortion.  My biggest question, though: will plain ‘ole IN4007 Diodes work in the circuit?  I plan to build this thing soon and all questions will be answered… always looking for new (old) sources of novel grit+crunch….

Categories
Technical

DIY Remote Broadcast Mic Preamp c. 1950

Download a four-page piece from RADIO ELECTRONICS, March 1950, on the subject of Build Your Own Two-Channel Remote Amp.  Author is Richard Finkbeiner.

DOWNLOAD: RemotePreAmp1950

Again with those T-pads.  Anyhow, we have here two 6J7 pentode stages in series supplying a 6F6 (v v similar to a 6V6) output stage.  Here’s the schematic:

The schematic is a bit opaque due to the fact that this piece is designed, ‘at the touch of switch,’ to become a cue amp – to receive signal, via its Station-Link, rather than send signal.  Confused?  The article will make it clear.  Anyhow, if anyone has tons of time on their hands, it might be interesting to re-draw this schematic minus all of that circuitry.  I would be v curious to know exactly which output transformer the designer used: a 5K to 600 ohm transformer that can handle 3 watts of DC and remains flat 30hz – 15khz?  Sign me up.  (It sure looks like a Langevin, but as I don’t have the early 50s Langevin catalogs, I can’t say which model it might be)  I can tell you that even the modern Lundahl that I use in my BRDCTR can’t offer quite that level of performance, although Lundahl does promise it…

Also of note to all you builders out there:  the author observed a full 15 db less overall noise with a 1620 in the input position relative to a 6J7 in same.  I wonder for how much longer we’ll be able to easily buy NOS 1620s…

 

Categories
Uncategorized

Fill In The Blanks

**************

*******

***

1.__________________

2.__________________

3.__________________

4.__________________

5.__________________

Use the comments section to weigh in.  ‘Correct Answers’ circa 1961 to follow next week.