Bozak Compact Speakers of the 1970s

Download the four-page circa 1975 ‘Bozak Compact Speakers’ Catalog:

DOWNLOAD: BozakCompactSpks

Catalog contains photos and specs for the Bozak Rhapsody, Tempo II (Tempo 2), and Sonora speaker units.

Bozak is another important chapter in Connecticut audio history.  The famous manufacturer of legendarily large home hi-fi speakers was based in Connecticut for the entirety of their 30-year heyday.  Pennsylvania native Rudy Bozak set up shop in Stamford in 1951,  later moving to South Norwalk and Darien, with operations in several other towns.  Wikipedia has an excellent and thorough treatment of Bozak, the man, his myriad technical innovations, and the long history of the company.  No need to re-tread those waters; I will add this though: growing up in Connecticut, enormous 225-lb Bozak Concert Grand loudspeakers were a memorable site in the homes of some of my friends; a room-dominating testament to the intensity of a largely lost culture of audiophiles.


Missile Testing, The Dawn of Video Surveillance, and Your Speakers

The fact that we are fighting three (3) wars at the moment (don’t try to tell me that those ‘drone planes’ in Lybia don’t represent a direct military strike) has me inevitably reflecting on the truth that we, America, are a militaristic nation first and foremost.  In a previous post, we learned about the place that the venerable Altec tube compressors played in cold-war ear civil defense warning systems, an important role that no doubt led to the relative bounty of these devices today. Which leads to an intriguing question: how does an audio-equipment manufacturer get involved in high-level government defense contracting?  Seems like a bit of a stretch, even in our highly militarized society. I mean, I don’t expect that Digidesign is making data-mining apps for the CIA….although as I type this, I realize that I am likely naive in this regard.

Anyhow, I found an answer to the question of Altec’s prominence in military/civil defense within the pages of the slim volume depicted at Left.  “TRADERS GRAPHIC” (h.f. “TG”) is a private-press investors-guide from 1960.   The cover price on this hand-stapled 32pp volume is $5, which would be $38 today.   TG is essentially a tip-sheet which alerts potential investors to publically-traded stocks which have ‘major growth potential.’   In January 1960, one stock which TG endorsed was Ling Electronics; and the primary reason given for this endorsement was Ling’s recent acquistion of Altec Electronics.


Nice use of the little star type-pieces as a paragraph break.  Anyway, prior to their purchase of Altec, what was Ling involved with?  Read below for the full details, but I can sum it up as: vibration testing of ICBM and other missile components, as well as (then-novel) closed-circuit television systems for retail spaces.  I.E., video surveillance.  Realizing this, it makes perfect sense that we would soon see Altec audio equipment in government-contracted defense applications.  Which, again, accounts in part for all the old Altec equipment that we still use today.  Kinda cringing as I type this, but this really is proof yet again that the industrial base of any society (in the case of America, military/defense) will always find a way to inform all other aspects of that society (in the case of us, dear readers, music recording and listening – The Arts).  Follow the link below for the full text on Ling from “TG.”

Continue reading Missile Testing, The Dawn of Video Surveillance, and Your Speakers

AKG K-340 Electrostatic/Dynamic Headphones c. 1979

Download the six-page color product sheet for the venerable AKG K-340 headphone of 1979:


The AKG K-340 (not to be confused with the modern AKG K 340 earbud) was AKG’s top of the line headphone of the 1980s.  Introduced in 1979, the K-340 took the basic design of the classic K-240 (which was very sophisticated in and of itself) and added the additional complication of a separate Electrostatic driver and associated crossover network.







Wikiphonia has a detailed entry on these unusual headphones, so no need to re-tread those waters; the six-page document I post here is some new material for the web, though, AFAIK.  Check it out…  and if anyone uses these cans, LMK yr thoughts…

Click here for previous vintage AKG headphone coverage on PS dot com

A Lost Fender Guitar Design – The ‘Acoustic-Electric’ of 1965

Looking through some old Fender Guitar Catalogs, I came across this unusual entry.

Behold the Fender Acoustic-Electric as it appears in the Fender 1965 Catalog (see catalog cover at right).  I have never come across any record of this instrument before, and yet there it is… photographed…  so at least one of them was made.

The Acoustic-Electric is pretty clearly the ancestor of the Fender Coronado, Fender’s ill-fated Gibson ES-335 competitor.  The  Coronado was sold from 1966 through 1972.   There are a few notable differences between the Coronado and the Acoustic-Electric tho – the pickup design, the tailpiece design, bridge style, and the knob/switch placement.  We also see a dot-neck on a two-pickup instrument (Coronados had block inlays on the 2-pickup instruments and dot-necks with single pickups), as well as the classic Fender headstock shape rather than the soft lower bout of the Coronado headstock.  Taken in total, these small changes seem to represent a deliberate attempt to make the Coronado a more ‘rock/pop’ instrument than the somewhat ‘classier,’ ‘jazzier’ Acoustic -Electric.  This change in direction would seem to correspond neatly with Fender’s purchase by CBS.  I have to wonder if the Acoustic-Electric represented the thinking of Fender’s old-guard, which lost influence once CBS took charge.  Who knows.  Anyway, has anyone ever come across a Fender Acoustic-Electric?  Or were they all destroyed?  Anyone?

Altec 436 Compressor: Taming the Output Level

Ah the classic Altec 436C compressor (see here for previous coverage on PS dot com).

Here’s a fresh high-res scan of the original product-sheet (2pp):

DOWNLOAD:  Altec_436C

I built one of these some years ago and it really sounds great.  I used UTC ouncer -series transformers.  Don’t be fooled by the tiny size – these are very good units.  In fact, Ouncers are used in the early Urei 1176 as well as UA-175 and 176 compressors.

You can see how super-simple the circuit is. Aside from using a conventional power-supply circuit (rather than the voltage doubler that the original unit uses), i built mine pretty much exactly the same as the schematic.

Now, if you look at the schem, you can see that there is no provision for an output control.  This is a problem because these things add a lot (like 20 db or more) level to whatever you put into them if you have the input control high enough such that the unit is actually compressing.  In the past I have gotten around this by using an outboard Daven H-pad attenuator that I mounted in a little box.  This is not ideal for ergonomic reasons.  Anyhow…  while studying the (very similar) Gates Sta-Level schematic the other day, I was intrigued by the very simple, very inexpensive variable balanced output pad that the Sta-Level uses.

It’s like $5 of parts. Five 1/2 watt resistors and one pot.   Based on information in the Sta-Level manual, adding this circuit after the output transformer of the 436C will provide a minimum 10db and a maximum 16db attenuation.  Perfect.  Now, it’s true that using this control will vary the effective output impedance of the unit slightly; but according to Gates, “This pad has been carefully tested to assure that the small impedance mismatch resulting from this range adjust-ment will not affect frequency response or other characteristics. ”   And Gates was writing this back in the day when the Sat-Level would almost certainly be seeing a 600ohm load.  Considering that nowadays it will more likely see a bridging load of 1500 – 10k ohms, I think it’s safe so say that this circuit should be (at least as) sonically-transparent (as a vacuum-tube vari-mu limiter can be).

Gonna dig up some matched 160 ohm resistors and give it a shot…  more to come…


Bass c. ’70

Just a few random things today that caught my eye.  The Hagstrom 8-string bass pictured above with players Noel Redding, among others, was recently re-issued.  seems like not a bad choice for live rock bands.   Tom Petersson of the not-terrible band Cheap Trick has used a similar contraption for years.   Yes I am joking btw Cheap Trick is rad.  ANYways…

Good lord.  Just in case the SVT is not big/heavy/loud enough for you, Fender swings back with 435 watt PS-400.  I have only seen one of these in my life; can’t recall when/where.  Great fan-site for these amps here…  interesting picks of melted (like, literally) 6550 tubes from some sort of biasing-mishap.  Proceed with caution…

The Fender Precision bass in classic James Jamerson trim.  Who is James Jamerson?  Books have been written…  but you can start here. Kinda invented maybe 25% of the electric bass guitar lexicon?  Rough guess.

The electric bass Jamerson played was a stock 1962 Fender Precision Bass which was dubbed “The Funk Machine.” Jamerson bought it after his first Precision (a gift from fellow bassist Horace “Chili” Ruth) was stolen. It had a three-tone sunburst finish, a tortoise-shell style pickguard, and chrome pickup and bridge covers (the latter containing a piece of foam used to dampen sustain). He typically set its volume and tone knobs on full. This instrument was also stolen, just days before Jamerson’s death in 1983. To date, it has not been found.



makin’ it

What is goin on here !?

The May 1979 issue of DOWNBEAT magazine has a short article on the subject of Do-It-Yourself synthesizer kits.  I’ve uploaded a scan of the entire article as a PDF below.  Much of the article focuses on kits from Paia.  Paia, if you are not familiar, is a very long-running company that makes audio kits.  One of my earlier experiences building audio electronics was constructing their Theremax Theremin. I got the Theremax together in about a day, and it worked right away. No issues.  I used it (mostly as a performance voltage-controller) for about a decade before I sold it at a moving sale.  It was a good, reliable piece.    I know that nowadays there are a lot of cheap theremins on the market, but 15 years ago it was a pretty unusual item.

DOWNLOAD ARTICLE: SynthKits_Dwnbt0579

Anyways…  PAIA still makes and sells descendants of the synth modules that are described here, and the prices are extremely reasonable.  A time-honored way of getting into audio electronics.

btw, dude in the pics here is not me, but it might as fukking well be.

Ward Beck Console Preamps: History, Preservation, Listening Test

Tom Gruning with one of his Ward Beck ‘lunchboxes’

I came across Tom Gruning’s work on eBay and I was drawn to the level of craftsmanship that he put into these largely unheralded Ward Beck pieces.  What’s/Who’s a Ward Beck you say? Well,  today on Preservation Sound we will learn a little about Ward Beck, the Canadian broadcast-audio-equipment manufacturer; take a look at some of Gruning’s work reinvigorating and preserving these pieces for use in the modern music studio; and we will conduct a listening/recording test of his pieces in comparison with some studio-standards.




TG work in the Shop

PS: Tell us about Ward Beck, the audio-equipment manufacturer.

TG:  As far as WBS history…their consoles were/are broadcast consoles that were/are very, very high quality. I seem to recall reading that Neve was their primary competition in that market during the 1970s and ’80s. Neve moved over into recording consoles and WBS stayed with the broadcast market. There is a really wonderful on-going WBS history thread in the forum at the Ward Beck Preservation Society website. I suggest all your readers go there and tune in as it is an absolutely fascinating first person account of that history.

PS: How did you get involved with converting old Ward Beck console modules into stand-along ‘plug-and-play’ rack units?

TG: I got interested in WBS equipment about five years ago. I was putting together my personal ProTools project studio and simply couldn’t afford excellent quality store bought mic pre-amps. Being a research guy, I spent inordinate amounts of time reading what people had to say about any and all console strips. These were, after all, considerably cheaper to come by than the plug and play Neves, APIs, Chandlers, and on and on. The Ward Beck stuff sounded like the best of the bunch in that first and foremost, people thought they sounded excellent and were built like tanks. There was also a really knowledgeable and helpful community of folks willing to help newbies like me: that is, the gang at the Ward Beck Preservation Society.

As I wound up learning more about making these things work, I started investigating different modules when I could afford them. At this point I have 460s, 461s, 462 and 472 EQs, a 466 compressor, 470s, and 490s in my personal stash. Eventually I’ll add some 441s and a few others I have my eye on.

PS: Tell me about the mic preamps that you sent me.

TG: The 49o pres I sent you started life as line level modules in a small, fourteen channel broadcast mixer. ….I pulled the first module and found the Hammond 6012 input transformer so I set about the task of turning these into mic-level units. It really didn’t take too much modification to turn them into mic level units and I wound up bypassing the logic circuitry in many of the racked pairs. Besides simplifying the signal path and eliminating the possibility of ICs crapping out, the mod (which I credit to legendary WBS guru Dave Thomas) gives the pre a pleasingly accentuated mid-range presence that really jumps out in a mix. They are great sounding pre-amps and prices on them are still very reasonable.

PS: Tell us about some of the different vintage Ward Beck pieces out there in the world.  What should folks look for?  What to avoid?

TG: I like the sound of all the WBS modules with input transformers. Bypassing the logic on the 490, the signal path is essentially the same as that of the 470. These sound really good on snare/high hat, electric guitars, and various other sources. The 460 series has a bunch of different designations: 460A; 460B; 460M; 460L,;460LA; etc. My favorites are the ‘L’ and ‘LA’ models simply because they are, as I recall, the most recent of the 460s and they have the really nice sealed pots, fully parametric EQ, and so forth. However, there really isn’t a hell of a lot of difference between the sound of an ‘A’ or ‘B’ and any of the others. The 460s have a big black custom made Hammond input transformer that really gives them a yummy, big, fat, round presence that is at the same time clear and nicely balanced. And they really are built like tanks. I’ve only run across two WBS modules that I couldn’t get up and running: a 466 compressor that I sent to Tristan Miller, a very talented Canadian tech who whipped it into shape, and a 461 mic-pre that I’m still banging on and eventually will get working. Most of the time, cleaning and radically exercising the switches, which are the only really weak link in the WBS chain, will get them passing signal.

PS: What Ward Beck ‘rack-conversions’ do you have available in-stock at present?

TG: I still have a few of the 490H rack boxes in stock (like the one I sent you). I also have a slanted front maple eight pack wired for six slightly modified 460 modules and two 470s. That one has a separate 1U rack mountable power supply. At present the box contains the two 470s, one 460L, and one 460LA. Oh yeah, I also have several 2U pairs of Yamaha PM1000 modules in my GruningAudioworks boxes. I have pictures of all these things on my website I also build custom-made hardwood cabinetry for WBS modules and various other things including exotic wood cabinets that house powered “picnic baskets” for API 500 series compatible modules.

Also, just as an aside: If any of your readers decide to rack up some WBS (or Auditronics, or PM1000) modules and would like some help, please feel free to contact me. In learning how to do these, I ran across a number of people who have been very helpful and generous with advice and instruction. If I can do the the same that would be good.




The Ward-Beck 490A input module in its ‘just-harvested’ state

(image source)

Alright.  Now on to the listening test.  TG sent me a pair of 490A modules which he had racked up, adding phantom power and system power in a very nicely fabricated black steel chassis.

I mounted them in a pre-amp rack at our new studio, Gold Coast Recorders (more on GCR to come…).    I have heard folks compare these Ward Beck preamps to API 512s.  I decided that this would make as good a comparison as any.  Especially since many of you are probably familiar with the sound of the API 512.

Our friend Tim W., recordist and drummer of the excellent band The Stepkids, came by GCR to help in this listening test.   Here’s what we did.  And it ain’t scientific.

Tim got behind a 20/14/12 circa ’64 ludwig kit that I had mic’d up with 4 mics:

-two Sennheiser 441s on the kick, and two Neumann 103s in front of the kit.

The mic pairs were spaced as close as possible.  One kick mic/Front mic pair went into the Tom Gruning-racked Ward Beck 490s; the other kick mic/front mic pair went into a pair of AP1 512s.  The outputs of the mic preamps went directly into pro tools.  no other processing was used, and the signals were played back and bounced with the faders at zero.

I asked Tim to play a beat inspired by this chestnut.  And here’s what we got.

Here is Tim’s performance as recorded thru the Ward Beck M490A pair:

LISTEN: WardBeck_M490A

…And as a reference, here is the exact same performance, recorded at the same peak level, but recorded thru the pair of API 512 preamps:


Here is a screen shot of the Pro Tools session.

You can see clearly that the Ward Beck kick channel (Kk) is limited in comparison to the API kick channel.  It’s also more symmetrical.  The room mics (OH), on the other hand, have similar dynamic range except on the strong peaks.  Perhaps this greater dynamic range  was due to the fact I used the pads (on both the API and the Wbecks) for the room mics but not the kick mics.  In case you are wondering about phase: yes I did try reversing the phase relationships on both sets of mics, and i can confidently say that what you here in these mono bounces is the correct phase relationship.

Tim and I listened back in the control room at GCR.  The room is outfitted with a Blue Sky monitoring system with their 12″ sub; the low-end extension and clarity is very good.  And this was very helpful for this particular evaluation.

TIM W: ‘The signal from the Ward Becks really moves the room.  It’s much deeper in the bass but not as punchy (as the APIs).  I can really hear the articulation of the Toms in particular (with the WBecks).  There’s less presence of the hi-hats and the cymbals in general.  The bass is really deep – there’s more length to the kick drum sound.

PS: The APIs are a lot more focused, but there seems to be an entire octave of additional bass extension to the kick drum with the Ward Becks.  I feel like it is unusual to hear mic preamps that have this much ‘attitude’ but actually have deeper bass than a high-end preamp like an API.  The low mids feel scooped on the Ward Beck; the high extension is not as good.  I imagine the Ward Beck would be great on rock bass guitar or maybe room mics for a kit.

TW: The API is giving me more low mids in the snare and toms, but i am not hearing that real low end in the bass drum.  (the API pair) is more ‘punchy’ rather than really bassy’




I encourage you to listen to the audio examples above and draw your own conclusions.  I feel like the Ward Becks are good addition to the rack; I am definitely excited to try them on an SVT cabinet, and some loud rock vocals too.  It’s definitely a very coloured sound – both in terms of the compression and the scooped low-mids and slightly rolled-of highs.  I will also give em a go on kick drum for sure.   Check em’ out on Gruning’s site; you might be pleasantly surprised how affordable they are.


Oddball dynamic mics of olden days

A quick review of some odd mics from the ‘pile’ that have not made it over to the studio yet.  If anyone out there is using these for makin’ records, drop a line a let us know yr thoughts.  Above is the Altec 660A, which is an Altec-branded iteration of an earlier western-electric mic. This thing sounds very thin.  it’s quite small – check the XLR connector for size reference.

Another ancient Altec mic.  this is a 684B.  This piece does not sound bad, but… it failed the SM57 test.  What, you ask, is the SM57 test?  Well…  whenever a new mic appears, i quickly A/B it with an SM57.  If the SM57 sounds both ‘better’ (IE more ‘hi-fi’) AND ‘more interesting’ (this is harder to quantify….), then the new mic goes in a box somewhere.  684B up there failed the SM57 test.

This is an American D4T.  This is a hi-Z dynamic public-address mic from the 40s.  This is, btw, the first antique mic i ever bought.  picked this up at an antique shop in Prov RI back in the mid 90s, along with a little tube suitcase PA system and nice old cast-base mic stand…  $75 i think….  This mic still works, and it sounds cool, but it’s just too distorted…  feel like it sounds too ‘Pop,’ of all things, at this moment; ‘distressed-vocals’ being the trendy thing that they are.

An Electro-voice military communications mic.  Got this one still in its heremetically-sealed, foil-lined pouch.  It ain’t bad, but…  i have too many mics like this, only just slightly better….

A Sennheiser MD 416.  I was really excited about this thing, and i paid like $100 for it, which is a fortune for a cheapskate like me.  Now, I have a lot of old sennhesiers…  an original 409, 421, and several 441s… and i really dig them… but this thing just has no… balls?  No low-end, at least.  And that Mini-Tuchel-to-XLR cable wasn’t cheap either.  This gets my vote for the most-expensive-mic-that-looks-like-a-really-cheap-mic.  I will call it Paris H. from now on.

Shure 585 ‘unisphere A.’  Basically a cheap hi-z dynamic with a volume pot built in.  I think this is known as the ‘James Cotton’ mic.  Cotton was a harmonica player in the 60s whi apparently used just about every amp and mic in existence at one point or another, cos there is really no limit to the range of items people are eager to associate with him.

Shure 777s Crystal mic with switch.  I think this came with a large pile of old mics.  It’s a 60 year-old crystal mic.   not much more to say.

Shure Commando.  Honestly not even sure what kind of mic this is.  Sounds pretty cool but it’s hi-z so it’s a pain in the ass to use in the studio.  harp (harmonica) dudes seem to dig these.

Shure PE-54.  The ‘PE’ stands for ‘Professional Entertainer,’ believe-it-or-not (seriously, though, this is true.).  This is the hi-z version of the Unidyne III… which is the forerunner of the SM57. This is actually a really good sounding mic, but since it’s hi-z, it’s a pain to use. I have an SM56, which is the balanced version of this thing, so this is kinda redundant.  but for real this mic sounds great.  i was surprised.

Turner 510.  The best dynamic mic Turner ever made.  I am actually not sure how this thing failed the SM57 test.  Think maybe it deserves another chance.  Look for a shoot-out including this mic.  here.  soon.