Cinema Sound Circa 1953

Today: some random bits+bobs of Sound-For-Film technology of the early 1950s.  Above: the All-New JBL Theatre Sound Systems, which claim to offer the higher-fidelity needed to properly reproduce the newly-available magnetic soundtracks that were being used in 35mm film at the time.  Prior to the introduction of magnetic 35mm film soundtracks in the 1950s, all film-sound was reproduced in theaters via an optical sound-track which ran alongside the edge of the film-frames.  Fidelity was limited, although I cannot say exactly to what frequency range.  Can anyone tell us what the first feature-film was to be exhibited nationwide with a magnetic soundtrack?

Above: Cinema Engineering presents… the fader!  Straight-line attenuators have certain advantages over rotary controls, such as quicker visual feedback and a range of motion that better correlates with human bio-mechanical consideration.  Nonetheless, rotary faders remained in use in pro audio well into the late 60s.  Does anyone know who first patented and/or marketed the linear fader?

Above: the Cinema Engineering 6517-E ‘Sound Effects Filter,’ aka a high-pass and a low-pass filter both built into a single instrument.   I could find this sort of thing very useful; especially for tracking multiple ‘stacked’ parts such as one singer delivering 7 vocal harmonies over a single phrase, as I found myself doing in a session earlier this week.  Just carve out all of the unnecessary super-high and super-low end… the 80 or 100 hz high-pass filter built into many mic preamps is certainly useful but it’s obvs not always the best cut off choice.

Above: an advert for Glen Glenn Motion Picture Sound Co. circa 1953.  Anyone out there work for this firm?  We’d love to hear yr stories….  drop us a line…

Above: RCA’s ‘film phonograph,’ an apparatus that records and plays-back 35 mm magnetic sound-tracks and plays-back 35mm optical sound tracks as well.  I ended up with a couple of 16mm sound track readers at Gold Coast Recorders; not sure what to do with them.  Has anyone had any luck converting an optical-track reader into a signal processing or signal generating device?  Seems like there’s some potential to make it into  interesting experimental instrument; strobe-light-controlled oscillator perhaps?



1953: What is High Fidelity?

Lee de Forest (L), the man who invented the voltage-amplifer tube, takes in the state-of-the-art in consumer audio reproduction c. 1953.

Download a two-page article on the subject of “What is High Fidelity” as-published right at the dawn of the hi-fi cultural phenomenon.

DOWNLOAD: IST-1953-09-Callen-What_Is_High_Fidelity

Audio.  From children’s toy to naval communication device to home entertainment to art, all within one lifetime.  What has changed significantly in our conception of the role of audio technology since 1953?  As this article makes clear, in 1953 ‘fidelity,’ or verisimilitude to some supposed acoustic event, was the ‘state of the art’ in audio, and contemporary technology such as the U47 mic and the Ampex tape machine was finally making this verisimilitude possible.  We now no longer have the expectation that a piece of audio ‘represents’ or ‘stand-in-for’ any actual acoustic event that ever happened in the physical world (Katy Perry track? Or Sgt Peppers?), but what have we gained?  What new expectations/demands do we have?

Altec Theatre Equipment 1955

Download the four-page 1955 ‘Altec Stereophonic Sound Equipment for Theatres’ brochure:


Units discussed, with text, specs, and images, include: A150-C 4-channel preamplifier; 1530T power amp; 1520T amp; 625 and 629A speaker systems.

The Altec ‘Voice of the Theatre’ (VOTT) auditorium/theatre speaker systems are oft discussed; the A5 and A7 and all the other numerous variants (data on which can be found elsewhere on this site) provided high volume and excellent frequency response in large motion-picture-exhibition theaters in an era when amplifier power was limited by the available technology of the day.  This unusual catalog provides a good look ‘backstage’ at the various bits+bobs that Altec made for the projection booth and as support for the VOTT systems.

Spring 2012

Bad Vibes is one of my favorite places to find out about new music, posting significant new tracks as well as exclusive interviews with recording artists.   The guys who run it also have really good taste in movies so if yr nextflix cue is running low, stop by there for some inspiration.  When I learned that they were interested in hosting a Preservation Sounds mixtape I was super-excited to get involved.  The concept here is similar to the previous dozen mixtapes I’ve done: everything is pulled directly from vinyl LPs I have dug up at the flea markets and estate sales of Western CT in the past 4 months; digitized in crystal clarity (+ plenty of old dust) via my trusty Benz cartridge and Apogee convertors.   The big difference tho: since this mixtape is ivegotbadvibes #0026, it is available for quick download at the Bad Vibes site: and: it’s been cut together into one seamless springtime jam.  Visit Bad Vibes to download the mixtape.

Follow the link below for detailed track notes and more of the best album art of all time…

READ ON::: Continue reading Spring 2012

Pultec 1977 Full-Line Catalog

Download the complete twelve-page 1977 Pultec outboard audio equipment catalog:

DOWNLOAD: Pultec-1977_catalog

Units covered, with text, specs, and photos, include: Pultec EQH-2, EQP-1A3, and MEQ-5 equalizers; Pultec HLF-3c and HLF-26 filters; Pultec SP3 and MH4 mixers.

Until I saw this catalog I had not realized that the original Pultec production run had extended into 1977.  These are the solid-state Pultecs, not the more coveted vacuum tube units that trade in the $5000 range, but AFAIK the actual equalization stages are the same as in the earlier tube units.  I have never scratch-built a Pultec clone, largely because the idea of hand-building the multi-tapped inductors always seemed a little daunting to me.   I recently found myself in possession of a large batch of various MiniDuctors, though, and I am wondering if these can be put service in a Pultec-type circuit.  The mH values are very close to those in the putlec schematics, but I cannot find any reference online to anyone building a Pultec using MiniDuctors rather than a large coil-wound inductor.  Anyone have any idea about this?




I have an upcoming session with an artist who wants to keep the album all live, very raw.  I am expecting it will be a fun session.  The material has a classic RnB/blues vibe, so I am considering running some live mixes to GCR‘s circa 1950 Magnecord PT6 along with the Pro Tools multitrack.  But which brand of ancient 1/4″ tape to use?  Perhaps these circa 1952 audiotape ads will help decide the issue…

Scott Laboratory Tube Amplifiers of the early 1960s

Flipping through some circa 1960AES journals I came across this pair: The Scott 140B preamplifier and 250B fifty-watt power amp.  The 140B pre claims a response of 1hz to 3.5Mhz.  This is absurdly good performance for a vacuum tube amplifier.  I am guessing that this is a transformerless piece.  Anyone have any experience with this unit?  A schematic?  Drop us a line.  The 50-watt power amp likely does use an output transformer; it claims a response of 5hz to 60K hz, which is outstanding as well.  Let us know if you’re using these in the studio..

Visual Culture

Feeling a bit of an 80s thing right now.  Jesus Christ you baby boomers.  You grew up in the 1950s, all industry and productivity and abundance (and unchecked racism, sexism,  and cold war terror), and THEN you got the 1960s, unheralded change, motion, sexual freedom, drugs, Godard, Psych, Soul, and space travel (and the draft).  When the 50s repeated themselves in the 80s, things seemed fairly optimistic.  And then we got the 90s.  Now as much as I love Pavement and email…

So if the 1990s (and pretty much everything that has followed) was a bit of a letdown, fukk it, we’ll always have the 80s.  Here’s some visual-story telling as it relates to certain Audio narratives/myths in the 1980s.  Feel free to discuss.

My girl is cool. She digs the old records.

A mere 10 years after Bridgeport-based Columbia Records introduced the LP record, we see evidence that record collecting was already a well-entrenched hobby/sport/folly.  At left is the cover of “Record Research” Vol . 2, No, 6, Issue 18, dated July 1958.  Of course, those folks (and maybe some of you are still kickin…) were more probably more interested in collecting 78s and Wax Cylinders such as our comely friend above is holding.  Stay tuned for an upcoming piece on Columbia’s history in Bridgeport… and for now, check out these bits of Columbia-collecting circa 1958.



State of the Art Sound Reinforcement c. 1961

I had a live-sound mixing job this past weekend.  The system that was hired was quite nice which made the job pretty easy.  Thanks to hypercardiod microphones, graphic EQs, and stage monitors, feedback is not really a problem with concert sound these days; instead we tend to wrestle with volume levels, stage volume in particular.  Above are two early high-tech methods of dealing with sound-reinforcement issues.  The audio instruments model 301 time delay is a tape-echo machine which was intended not as a creative effect but instead to time-align speakers in a multiple-speaker system.  As far as i can recall, this concept was made popular by the Grateful Dead in their massive arena systems of the 70s and later, and is now a defacto part of most large sound installations.  Below that unit is the AI model 400 feedback supressor.  Rather than employing frequency filters or dynamic control, the model 400 is one of an early category of feedback supressor (ALTEC made a similar product and I imagine there are others as well) that reduces system-wide feedback by shifting the entire frequency spectrum by some small amount, 1 or 2 hertz I imagine.  The result?  What goes ‘IN’ to the system is never the same as what goes ‘OUT’ of the system, so any ‘feedback’ is never linear and therefore a stated 6 to 12 db of additional gain becomes available.  This is a fascinating concept that never went very far for some obvious reasons.  You might never notice a shift of 2 hz on a violin part or a human voice, but bass guitar or organ?  That could easily result in a 25% sharpening or flatting of the note.  Bad news.  I don’t know exactly what lead to the discontinuation of these sorts of devices, but I imagine that it may have been at least partially due to improvements in filter design that allowed inexpensive graphic EQs and fully-adjustable parametric EQs in the 1970s.   I am very curious to know what feedback DID sound like when one of these frequency shifters is used:  is it a long gliss up or down the pitch range to the maximum frequency response of the system?  Anyone have experience with this?

information and ideas about audio history