Wednesday, October 17, 2012

WE/Altec 755A: You pays your money and takes your choice

Checking prices of 755A on ebay, all of the numbers look insanely high to me. Like WHOA, is that in dollars or Korean Won? I saw a pr of perfect NOS Western Electric early and rare silver units go for over $7k a few weeks ago that is some crazy cash!! Woo-hoo!

I guess my head is still stuck in the 80s, when you could buy 755As all day long for $100 or less.  Most people, even vintage audio guys, didn't understand what they were and most people would think you were nuts if you wanted to pay $100 for a damn eight inch speaker. I used to find 4 or 5 a year without even looking specifically for them and I was so cheap I'd want to pay $5-10 apiece, but I probably paid $100 for a few after I got hooked. At a certain point word was out and the price jumped to $150. Priced me out of the market!!

After all, the 755A is not a rare speaker. They made many tens of thousands of these things. They went into sound distribution systems 10, 20 and 100 at a time. True they were mostly outside the hi-fi orbit, except for their use in AR-1 and some DIY use of surplus units in the early 50s. Presumably, even back in the 50s most hi-fi nuts probably considered it a mundane PA speaker while using vastly inferior home audio junk with cheap Jensen and University drivers. Some things never change.

Today, most of the 755As are gone to the big dump in the sky and demand now outstrips supply, and the prices clearly reflect that imbalance.However, any item that shows up on ebay in five listings a week is not a rare thing. They are just hard to find and buy when you want them, like any oddball 60 year old object.

There is a big spread in the prices that 755As fetch, corresponding to age and variety, kind of like collector coins or baseball cards. Obviously, the WE versions sell for a big premium over the Altecs, largely thanks to the superior fetish value of that WE sticker. That might be the only reason.

Back when I had a quantity of different 755As on hand, I could not detect any significant difference in the early WE units compared to early/mid 50s Altec units....probably because the Altecs were built with parts handed down from Western stock, so there really wasn't much difference. Of course, WE branded 755As are far less common than Altecs since WE only made them for about 2 years and Altec cranked them out for a decade.

Condition of individual units contributes a much greater variation in sound quality than the paint or the sticker. Dried out brittle cones sound a lot different from fresh looking black cones. I used to like the slight extra speed and feathery texture of the dry, bleached out, light tan color cones. In a front-mounted slant box, these used and abused 755As were detail demons.  I have heard 755As with many repairs and even open holes in the cones sounding pretty decent. However, If I were paying today's stupid prices, I'd definitely be looking for nice minty specimens with fresh looking, pliable dark cones.

Another point of condition is the state of the mysterious sticky goop damping material 755As have on the paper hinge. It is on both sides, by the way. Often this stuff has evaporated and there is only a trace left. Sometimes it soaks into the cone, which looks like hell but doesn't impact sound much. if at all. What scares me the most is when there is a lot of it left but it has become hardened and stiff, a condition which looks really good but this has to change the parameters of the speaker.

I have a nice 756B with this hard goop problem and I measured a notable difference in fs between it and another 756B with only a trace of remaining goop.  I painted some acetone on the petrified goop to soften it and I measured the resonant frequency going down as it softened up.  I'll unbox this driver someday after playing it a lot more and compare the TS sweeps with the pretreated and freshly treated measurement and see if I got any long-lasting benefits from the experiment. I wrote up the initial phase of this experiment over on the Altec Users Board.

If you want to try this, be very conservative with the solvent so it does not attack the paper. Some people report that a hair dryer will soften the goop also. I am not sure that any of these fixes are permanent. I do like the idea of softening it somehow and then playing the speaker a lot to loosen things up. Many 755As have been sitting around unplayed for decades and need some exercise.

I asked 755A specialist Yuzo Doi what do do about this problem and he did not like the idea of using any chemical solvents on ancient fragile cones. He says that the best way to handle mismatched 755As is to carefully adjust the damping material in the cabinet to match them up- see the previous post on cabinets. Play for a while and compare again.

According to Mukai of Western Sound, Inc, the primary difference between Altec and WE units is that WE used that spongy paper Kimsul for damping material in the hole of the donut Alnico magnet leading to the cloth back vent and Altec used glass wool. 

He adds that there seems to be a switch in cone formulations for the later Altec units, probably from a latter-day run of cones when the original WE stock ran out. I looked at at least a dozen 755As over the last few weeks and I can't detect any difference beyond individual aging and condition factors, but I would not dismiss what Mukai-san says because for every 755A I saw, he has seen at least 100.

Also, contrary to misinformation found on the net, all 755A versions are 4 ohm nominal (typically 2.7-2.9 ohms DCR). The only 8 ohm alnico 755 variant I know about is the 755B which was used as a woofer in the Altec Lido (corrugated cloth surround cone on an A frame/magnet).  I think the low DCR voice coil goes hand in hand with the low flat impedance curve across the bandwidth of the driver! Correct me if I am wrong and you have actually seen and measured an 8 ohm 755A! (755C and 755E are 8 ohms)

Anyway, here is a basic rundown on 755A varieties:

Early WE silver version 1947

Here's the 755A version that really goes for big cash.
Why? No good reason, as far as I know. Very sexy though!

WE  GrayWrinkle 755A

Like that cool WE decal? It adds thousands to the price
over Altecs made with the same parts.

Altec Gray Wrinkle version  1952-1953 date codes

Altec Silver Hammertone 1954-58?

Most common 755A version, found in AR-1 speaker.
Some silver Altecs have the old style decal pictured above
on the gray wrinkle unit. It seems Altec never threw anything away....

KS SPEC 755A / KS-14703

Often treated as a separate variety of 755A is the "KS" version. These were procured for Western Electric internal use and show up in WE wall cabinets and telephone office each mount cabinets and the like. They are obviously made by Altec although they do not state the manufacturer in plain language, only via EIA code and it is not on all of them. 

BUT the one pictured below has a code of 502588 (8/1958 date) while the EIA code for Altec is 391xxx and that is what is usually seen on KS-755As. Who was 502? Could some of these KS units have been assembled or marketed through a third-party subcontractor?

For some unknown reason, KS units cost more than identical Altecs and people have themselves convinced that they sound better too. Actually the reason isn't unknown...more WECo magic mojo rubbed off on them. People also treat those lousy wall cabinets like they are some kind of holy design. People are even reproducing them. Face it, it's a lousy, leaky 1 cu.ft. wall cabinet...actually probably a decent wall cabinet for a shoe store but a total waste of a 755A.

WE wall cabinets--keep an eye out for these in old churches and bus terminals!

Beware, because the KS-14703 designation also shows up on the later ceramic 755Cs, which presumably meet the requirements of the specification as well as the A version.

KS-14703 out of a WE wall cabinet.

Cone of KS spec 755A with WE inspection stamps on gasket.
Note: 502xxx is not the EIA/RETMA code for Altec!

Early Altec Brown/Gray Wrinkle 755A with WE QC stamps

Now here's a 1952 date code 755A I've been listening to. It has the same "WE 34" acceptance stamp on the gasket as the later KS version. I have also seen a few KS decals on early wrinkle Altecs.

I am sure this old 755 is worth some stupid loot, but still not as much as one with a Western Electric decal, maybe only half as much. Is there any reason to think that an Altec made with parts handed over from Western Electric two years after WE stopped assembling them themselves, probably made on the exact same machines, and which passed WE inspection, is in any way inferior? Well, price-wise, it is.

I have seen pics of late model brown 755As with a "modern" Altec decal on the web but never owned or held one. Maybe this was the last version made before the switch to 755C but as with all things Altec there are a lot of undocumented cosmetic and non-critical parts variations probably based on what was laying around in the warehouse. Industrial end-users surely didn't care about paint color. If anybody has one, send me a pic and I will add it to the post.

The only factoid that gives me pause to prefer one variety over another is the report from Japanese experts that the cone formulation changed for late runs of cones. Otherwise, it is all collector mania, which might matter to some buyers but not to me! 

Shop by condition or price rather than snob appeal and you should be on the right track audio-wise. As for investment advice, your guess is as good as mine. Past performance is no guarantee of future success!

Like I said before, 20 years ago, the 755A was the "workingman's revenge" choice, sounding a lot more engaging than all the high end mini monitors that cost so much more. Now the 755A is an upscale antique luxury item that will follow the money wherever on the globe it is found. If you've got it, go for it. You won't be bidding against me!

Those of us in the US still have a chance to get lucky and find one or two units in situ. The last one I bought, a few years ago, came in a blackface Fender Vibro Champ that I paid $250 for. The amp is worth $500 so the 755A cost me minus $250!  Beat that!


  1. Every time I see one of those wall mount cabinets I start my WE 755 chant but alas so far no score.

    great post

  2. Have been using 56 Altec 755As for quite a while, got mine from a fellow Audiomarter and Virginian. Have used them "nude" just hanging from picture wire from the ceiling to large plywood baffles, very satisfying if you don't get too wound up over the fequency range, covers enough to show you what is really happening music wise. Use them to help dial in my mutant Altec 821/MR94 setup which does have more lows and highs, and shear volume. Would not sell the 755As ever, will need them at the old folks home sooner than later and large corner horns wouldn't be appreciated in an apartment type of living situation. Joe is right need a amp that doesn't get in the way of the Uniates attributes of the 755As, need speed, and coupling and the first watt needs to be excellent, surprising loud. Can't go wrong with them, highly recommend.

    BTW Joe, thanks for coming back, SP is considered a reference and instrumental in getting the horn/SET move jump started in the USA, along with Walt Bender. The two of you were real drivers in helping us rediscover what makes music and tames the inner beast.

    Again thanks for starting this site, look forward to your future writings.


  3. I've got some Altec 755As stamped 501239, but I can't seem to figure out what the 501 stands for. Made in 1952? 39th week? Similar to the 502s above. I've looked up RIM codes, EIA codes, etc. and can't make sense of "501" There's another stamp with three characters in a circle, but they're illegible. Any idea what to make of it?

  4. I have a set of Altec "Lidos " that I have been using for some time now and decided to open the back and see what was inside .....!!!!! 755B and 402A ....sweet!!!!!! I would post pics here but not sure how to do that ..LOL

    1. also the S/N number on the cabinets are brother and sister "361" and "362",,,,LOL

  5. I got a pair of Altec 755A's via Audiomart back in the day from the one and only Vincent Gallo!