Categories
Altec Custom Fabrication

Altec 436C style compressor build #2

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.

Categories
Antique Hi-Fi Archive

Terminal Radio 1949 Recording and High-Fidelity Catalog

Download the entire 16pp TERMINAL RADIO Recording and Hi-Fidelity Equipment catalog:

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,,,,

Categories
Pro Audio Archive

Highlights from the 1970 AES Convention, Los Angeles, CA

GRT_deckabove: the GRT 500 audio-tape evaluator c. 1970

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.

AES_1970_1AES_1970_2AES_1970_3AES_1970_4AES_1970_5AES_1970_6AES_1970_7AES_1970_8

Categories
Technical

From the why-didn’t-i-think-of-that-first file – Great EZ hack for Octal can transformers

FirefoxScreenSnapz001Via this eBay auction: a UTC A-12 mounted on a plate-retained octal plug, with the pins wired to correspond to the pin-out of an Altec 4722 input transformer.

FirefoxScreenSnapz002It 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….

Categories
Guitar Equipment

1977

Roland_GR500_1977

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.

Altec_gtr_amps_1977 Canned_Heat_Randall_ad_1977 Charvel_Bodies_1977 Cruman_CPB1_1977 EH_Deluxe_MemoryMan_1977 EV_PL76_mic_1977 Kelsey_Mixer_1977 Marshall_ad_1977 MusicMan_fullLine_1977 Mutron_Flanger_VolumeWah_1977 RecordingStudioDesign_Mixer_1977 Stage_amps_1977 Travis_bean_gtr_1977

 

 

 

Categories
Pro Audio Archive Recording Studio History

Consoles of the 70s : part 2

Auditronics_Grandson2_1975Above: the Audiotronics Grandson II console circa 1975

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.

Quad8_2082_Console_1972Above: Quad/eight 2082 console circa 1972

Interface_series_100_mixer_1973Above: Interface Electronics Series 100 console circa 1973

SAIT_Console_Belgium_1973Above: Sait, a Belgium maker, offered this board in ’73

Allen_Heath_248_1973The Allen+Heath 248 portable mixer circa 1973

ADR_Consoles_1973ADR console circa 1973

Auditronics_Grandson_Console_1973The earlier iteration of the Audiotronics Grandson, this one from 1973

API_1604_Console_1974The API 1604 as-seen in 1974, and as still-seen in studios worldwide

Sphere_Alpha_Mixer_1975Sphere was a high-end console-maker that I know almost nothing about; here we see their ALPHA, a compact model from 1975

Interface_104_108_1976In 1976 Interface offered the 104 and 108 series consoles

Trident_1977Above: 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.

SpectraSonics_consoles_1977Above: Spectra Sonics console circa 1977.

Yamaha_PM200_1980The Yamaha PM2000 of 1980, successor to the -“Japa-Neve” PM1000.  And apparently even better?  Weigh in…

Langevin_Consoles_1970The Langevin AM4A of 1970.

Fairchild_portable_Console_1970Here’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?

Fairchild_Integra_Console_1968…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?

Fairchild_Integra_Components_1968…and here’s a breakdown of all the aforementioned bits+bobs.

Langevin_AM4A_Console_1968While 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?

Wigend_WAL100_ChannelStrip_1969Wiegand Audio Labs offered their Model 100 channel strip in 1969

Olive_2000_Console_1972Montreal 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?

Altec_9300A_Console_1970

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

Studer_189_Console_1972Above: Studer 189 circa 1972.  Just $148,000 (no typo) 2013 dollars! 

SpectraSonics_Consoles_1972Spectra Sonics 1972

Olive_2500_Console_1972Olive 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…

Categories
Altec Pro Audio Archive

Altec full-line 1976 catalog

Altec_1976_Catalog_Cover70’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

Altec_Cinema_1976Above: 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.

Outboard_Altec Altec_VOTT_1976 Altec_Studio_Speakers_1976 altec_Mics

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
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
Antique Hi-Fi Archive

Visual Culture: the late 1970’s

Today on PS dot com: a quick survey of some wonderful Hi-Fi visuals circa 1977.  Above: Fuji blank cassette media.  My latest embarrassing collecting habit: dead stock unopened blank cassette tapes. Because why not.  Report to follow.

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