I’ve serviced and modified many Altec 43X-series compressors over the years, but I think this may be only the 2nd one I’ve built entirely from scratch. Styled more like a Federal AM864, this unit incorporates many of the tweaks and modifications that I have come to like in these machines. Here are some images of the build.

Couple of things to point out in the photo above. Note the larger “Octal” tubes (6X5 rectifier and 6SN7 output amplifier) on the left side. I like octal tubes, as the larger sockets are easier to work with, so space-permitting I tend to use them. The original 43X used a solid-sate rectifier (with a voltage doubler) but I used a more conventional full-wave supply with a rectifier tube since it suited the look better. The 6SN7 output tube was a nice choice as there are so many variations of this tube available. It’s a direct sub for the 6CG7 in the original Altec.

Also note: behind the meter is a ‘meter null adjust’ pot. I can’t recall how this was handled on the original Altecs, but this mod is a common one shown on many internet schematics of the 436. Also note the large pot to the left of the meter. This is the Gates Sta Level output trim control (-6 to -14db cut) that I detailed on this site years ago. A worthy and necessary addition!

You can also see the enormous output transformer in the center: a massive potted unit built for Daven, likely by UTC. originally built for hi-end test gear, it is ultra hi fi and handles more level than this thing will ever see.

Above: some detail of the meter. I was motivated to build this thing solely because I found that original Altec panel meter at a hamfest for a buck. Seemed like it needed a 2nd life… Also check out that finish on the panel! That’s about 6 layers of paint and 3 layers of clearcoat, sanded between each coat. The knobs are all NOS 1960s DakaWare, acquired from Park Distributors in BPT CT (RIP).

Above: the UTC A18 input transformer, which has similar specs / ratio to the Peerless plug-in unit that an original Altec would have been outfitted with.

Above: the completed unit on the bench. The input pot is a really nice dual-gang 50K 1-watt sealed unit; I got several of these from Park before they closed. I cant imagine that any pot like this is available today for under $50. Good find. Running the length of the unit to the immediate right of the turret board is the heavy copper ground buss. Every ground in the machine connects here, and only here, and the ground buss meets the chassis at only one spot – the input jack. I swear by this construction technique. I’ve rewired a lot of old cheap tube guitar amps with this addition and the improvement in noise floor is remarkable.

DOWNLOAD: Terminal_Radio_1949_Catalog

Products covered, with text, some specs, and photos, include: Brush Magnetic tape recorders BK414, 710B, 810, and 808 Twin-trak; hi-fi tube amps from Brooks (10C3, 12A3), Meissner 9-1093 tuner amp and  9-1091C, RJ-12A tuners; tuners from Browning, Many Stephens Tru-sonic speaker systems and drivers including P-63HF, P-52A, P-52LX, P-52HF; Hi fi amps including Scott 210-A, Fisher SA-1, Altec Lansing 323B, Newcomb HLP-14A, Bogen PX-15, Thordarson 31W10AX; Bell 2122, Masco MA-12EZand Rauland 1825; FM tuners from Espey, Meissner, Craftsmen, Howard; Customode hi-fi furniture and cabinetry; Altec drivers including the 603B, 600B, 400B; Jensen drivers incl. JRP40, HNP-51, JAP-60; Cinaudagraph speakers CIN-12A, 15B, 15C; and so, so, so much more.

Follow the link below to READ-ON,,,,

Altec 323B amplifier circa 1949

As I write this I am listening to a Roger Eno record on stereo Altec 323 clone that I built earlier this year.  I’ve been kinda into this early hi-fi gear lately; postwar mono tube equipment.  It’s still relatively plentiful and inexpensive; the very early electrical sound gear (1920s and 30s) is/has been collectible and expensive for some time now, and the stereo tube amps that were popular in the brief period between the popularization of stereo recordings and the popularization of transistors (let’s say approx 1957 – 1967) are / have been v valuable because, well, stereo.  But I still manage to find several great mono tube amps circa 1945 – 1955 every year for cheap.  Easy to restore, great to look at, and then WTF to do with them?

Terminal was an interesting outfit; I wonder who bought them out?  I can’t find much record of them past the early 50s, and this catalog itself was pretty tough to track down.   They def seem focused on the mid-to-high end; there is none of the really cheap stuff that you will find in the ‘BIG’ catalogs of the era like Allied and Lafayette.  A few themes to note: Dynamic noise suppression – many of the higher-end amplifiers on offer here feature this.  A ‘downward expander’ to create near-total-silence in tacit passages, as well as to expand dynamic range that was compressed in the mastering process, was REALLY popular for a brief period in the late 40s (even the RCA receiving tube manuals offered this circuit, IIRC), and then again in the early 70s (think all those useless DBX wood-sided expanders that still litter thrift shops to-this-day).

While on the subject of noise-supressors: the above SCOTT unit is fascinating by virtue of it’s power supply (IE, lack thereof). It comes with an octal adapter that intercepts both B+ and filament voltages from an octal power tube in your power amp (presumably the ground came via the audio-jack-ground).  Given that most every American amp of that era used 6V6 or 6L6 tubes, this made the unit suitable for use by most consumers. This is a great idea to potentially use in designing, for instance, an add-on tube reverb or tremolo unit for a guitar amp.  Gonna put  that one on file,,,

Gigantic speakers? Check. When trying to make big low-frequency sound from scant watts (most of the amps on offer here are 10-30w), there’s ‘no replacement for displacement’ and yr gonna need a big box.  Man, I cannot tell you how many of these giants I’ve hacked up over the years to salvage the drivers (some of which I have been able to sell, many still line my shelves), but who has the room?  I recently got a very very nice BOZAK circa 1950 three-way coaxial system that I restored and saved, but I just can’t imagine ever having enough space for a pair of these things in the house.  Recording was at in interesting moment.  Simultaneously on offer are: wire, disc, and tape recorders.  We know which of these technologies won out in the end.  You can probably still buy a new cassette tape recorder of some stripe on Amazon, but a wire recorder?  Portable mini-lathe? Unlikely.  This catalog features disc recorders from Presto and Rek O Cut; Presto would soon move into the magnetic tape field, and Scully would eventually poach a top Presto engineer to develop their iconic (and excellent-sounding) 280 series machines. Curiously, this catalog does not include the Magnecord PT6, which may have been just slightly outside the pricing point that Terminal was at.  The PT6 was sold by most other big retailers by 1949, and would become one of the most widely-used tape recorders of the 1950s.

Good old GE 1201 D.  Maybe it’s because we were a GE Town, but these things pop up all the time around here, and so far they all still work!  And sound good.

103-S Transcription arm (tonearm) from Gray, another (semi) local maker of the era (Hartford).  Not east to find, and many are quite valuable.

Astatic EA2 phono preamp/EQ. Similar to many other higher-end preamps of the era, this allowed the user to tailor playback response to the particular record; this was necessary in the era before the standardization of the RIAA encode/decode curve.   Many ‘better’ integrated amps of this era had similar facilities, but not quite as extensive and versatile as this three-knob system.

Finally: Thordarson 31W10AX hi-fi amp.  Many transformer companies offered amplifiers, in kit and/or assembled form, in the era 1930 – 1960.  I have never encountered one of these Thordarsons, though.  Anyone?

Just in case you were too-young/too-hypothetical to have attended, we are pleased to bring you highlights from the 1970 convention of the Audio Engineering Society (via ye olde DB Magazine, r.i.p.).   You can download the whole shebang here…

DOWNLOAD: AES_1970_DB_mag

…and we’ve also reproduced it below for your browsing enjoyment.  Products on offer at that time include: mixing consoles from Electrodyne, Gately, Quad-Eight, Spectra-sonics, Fairchild, Langevin, and Altec.  Opamp labs had kits on offer as well.  Tape machines include 3M, Otari ‘of Japan,’ Teac 7030, GRT 500, Norelco (Phillips) pro-51, Sony Superscope TC-850, and Ampex. Dolby’s model 360 N/R system debuted, as did the Melcor ‘all electronic’ reverb and the Urei LA-3. New microphones on offer included the Electro-voice DS-35 and the Shure SM-53.

It had simply never occurred to me that the mounting-diameter of a UTC A-series corresponded to the mounting-diameter of those octal-mount plates.   Well done sir.  Great idea if you have an Altec 1567, 1566, or ANY piece of old pro audio gear that uses octal transformers – and a great many do.  RCA, Newcomb, Ampex, the list goes on….

Today: a random display of offbeat bits from 1977 that caught my eye: a tiny homage to the wonder that is The Internet K Hole.  IE., draw your own connections/conclusions.

Way back in October of 2010 I ran a short piece about some 1970s audio consoles, and now 70s month rolls on with an extensive image gallery of some iconic and some obscure mixing desks from that decade.  I’m a hardware mixer fan; I learned audio production in a studio with a Trident Trimix and my brain often just defaults to finding solutions and working-methods that are faster to do with a real console rather than via a DAW.   I would never give up my Pro Tools, no way… but I honestly can’t imagine giving up the flexibility and endless options that a good-sounding, full-featured console offers.  At Gold Coast Recorders, our Wheatstone SP6 has been going strong for two years now; I’ve had to replace the control room section due to a weird intermittent issue, but I since I had planned ahead and bought a spares-board it was pretty painless.  If you look past the real fetish-brands like API and Neve (great stuff, no doubt) there are a million bargains to be had if you are able to do a little tech work (or pay a decent technician).  I bought both of my SP6s for about $1500, TOTAL, with shipping, and put about 60 hours into arriving at a single great-functioning piece, fully cabled to my patchbays, and with a lifetime worth of spares.  Considering that these SP6s cost around $40,000 each in the mid nineties, this is a pretty great deal.  I guess I’d sum it up this way: if you record bands, if you have the physical room for a console, if you have the patience and/or where-with-all to do some basic troubleshooting, and the board is modular (very important….), I feel like you really can’t go wrong.  Given the outrageous prices of vintage outboard gear on the market today, vintage consoles represent an amazing bargain.  And a potentially amazing headache.  So be careful.

Above: Quad/eight 2082 console circa 1972

Above: Interface Electronics Series 100 console circa 1973

Above: Sait, a Belgium maker, offered this board in ’73

The Allen+Heath 248 portable mixer circa 1973

ADR console circa 1973

The earlier iteration of the Audiotronics Grandson, this one from 1973

The API 1604 as-seen in 1974, and as still-seen in studios worldwide

Sphere was a high-end console-maker that I know almost nothing about; here we see their ALPHA, a compact model from 1975

In 1976 Interface offered the 104 and 108 series consoles

Above: the Trident range circa ’77.  Apologies for the poor scan, I think I may need to invest in a new scanner.  As I mentioned at the head, I learned on the Trident Trimix, which was a ‘portable’ unit (portable but still around 150lbs!) that was offered a bit later.  I later learned the dark side of the Trimix is that…  aside from the mic inputs, none of it is balanced and the signal-to-noise ratio is very poor.  Which brings up a good point: before investing in one of these things, research the specs.  What I hadn’t known then is that the Trimix was originally conceived of as a live console… designed especially for Queen, if I recall correctly…Anyhow, yes the EQ sounded amazing and the build quality was high but it was far too noisy for modern productions.

Above: Spectra Sonics console circa 1977.

The Yamaha PM2000 of 1980, successor to the -“Japa-Neve” PM1000.  And apparently even better?  Weigh in…

The Langevin AM4A of 1970.

Here’s an unusual one: The Fairchild Portable Console of 1970, likely one their last pro-audio products.  I have never seen one of these before.  Anyone?

…and not quite the 70s, but…  Fairchild introduces their INTEGRA console, 1968, with the bold notice “No Audio In The Console.”  It’s pretty incredible how ahead of its time Fairchild was.  Anyone ever use an INTEGRA?  Did it sound good/work well?  Bits and bobs from these monsters seem to surface on eBay all the time, but I doubt there is still a complete unit out there.  Anyone?

…and here’s a breakdown of all the aforementioned bits+bobs.

While all of the Fairchild Integras may have been carved up, the Langevin AM4A, certainly the opposite end of the technological spectrum, seems to have fared quite a bit better… I often see these on the market in the $10K range, and I have to admit I have often been tempted…  Can any one tell us how these compare in terms of noise and response to a modern summing mixer?  Anyone using these to mix thru?

Wiegand Audio Labs offered their Model 100 channel strip in 1969

Montreal represent!  I KNEW there had to be a Montreal maker of boards in the 70s… and sure enough, we find OLIVE.  Here’s the Olive 2000 circa 1972.  Seems lost-to-history…  anyone?

Much closer to Langevin than Fairchild, here we see the Altec 9300 circa 1970

Above: Studer 189 circa 1972.  Just $148,000 (no typo) 2013 dollars! 

Spectra Sonics 1972

Olive also offered a 2500 model in 1972

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If any of y’all are actively using any of this stuff, write in and let the world know how they are in terms of sonics, reliability, and general utility.  There is very, very little information online concerning some of these pieces, so you could end up being very helpful to some potential future user of these these machines…

]]> https://www.preservationsound.com/consoles-of-the-70s-part-2/feed/ 25 https://www.preservationsound.com/altec-full-line-1976-catalog/ https://www.preservationsound.com/altec-full-line-1976-catalog/#comments Sun, 17 Feb 2013 10:51:10 +0000 http://www.preservationsound.com/?p=6113 70’s months at P S DOT COM continues with a fresh scan of the complete 1976 Altec pro audio catalog, complete with pricelist.  Presented in two parts due to file size.

DOWNLOAD PART 1: Altec_1976_part1

DOWNLOAD PART 2: Altec_1976_part2

Above: Altec’s classic Cinema loudspeakers, including (LR) the 1,300lb A2 speaker.

Products covered, with text, specs, and photos, include: Altec 1240B, 1208B, and 1218A ‘Voice of the Theatre’ speaker systems; 1221A stage monitor, 1219B speaker and 1224A Bi Amplifier, Altec A2, A4, A4X, A5X, A7-8, A7-500-8, and A-8 VOTT; Altec 9845A, 9844A, 814A, 849A, 210, 211A, 612C, 614D, 815A, 816A, and 828B speakers; 604-8G, 620-A, 9844, 9845A, 9849-8A, 9849-8D studio speakers, Altec 203B, 311-60, 311-90, 803B, 805B, 1003B, 1005B, 1505B, 32B, 511A, 511E, 31A, 511B, AND 811B horns; Altec 1211A and 1217A column loudspeakers; 417, 418, 421, and 425 musical instrument speaker; plus many many more speakers and speaker components.  We also see the Altec 1220AC mono console, 351C, 1590C, 159B, 1594B, 9440A, 1224A, 1609A amplifiers and 1606A, 1607A, 1608A, and 1611A mixer/amps; Altec 1628A, 1592B, 1599A, and 1589A mixer/preamps; 1603 coupler, 1605A expander, 1612A compressor, 1650 EQ, 9430A digital delay (looks like a lexicon-made unit) and 9880A filter; a load of other bits and bobs, and microphones including the Altec 650, 654, 656, 655, 677, 676, 668, 699, M53, M54, 624, 626, and 687.

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….

Altec Model 15 and Model 19 loudspeakers

Empire Phono Cartridge

Hitachi metal-cone speaker drivers. Who knew?

Jennings-brand Hi Fi speaker systems

Experimental binaural headphone system by JVC.  500-cycle crossover point; highs originate in front of the face, lows from above the ears.

Above: KOSS headphones, for both pop/rock and classics

NIKKO Hi-Fi components

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