AR chicao Industrial Capacitors

[Drewb]

I took the cardboard off of a spare Chicago Industrial Cap (6mfd) from a AR2 and found it to be film and foil in wax.

This is like some very expensive modern caps. It seems to me that these would be better than the Solen film types that many people use as an upgrade. It alse seems that this type of cap would have an unlimited lifespan unlike electrolytics.

My only question mark is that they measure 8mfd not 6mfd. Would the value increase over time?

Is my thinking right to reuse these or would I get a better result from the Solen's?

Thanks,

Drew

[Guest dogmeninreno]

>I took the cardboard off of a spare Chicago Industrial Cap

>(6mfd) from a AR2 and found it to be film and foil in wax.

>

>This is like some very expensive modern caps. It seems to me

>that these would be better than the Solen film types that many

>people use as an upgrade. It alse seems that this type of cap

>would have an unlimited lifespan unlike electrolytics.

>

>My only question mark is that they measure 8mfd not 6mfd.

>Would the value increase over time?

>

>Is my thinking right to reuse these or would I get a better

>result from the Solen's?

>

>Thanks,

>

>Drew

Drew, I have had almost 0% problems with the original caps AR used. Others swear they have good results replaceing them. Also silver wire is discussed as a major improvement? Maybe use and volume levels through their life has damaged the caps? Solen is a good sub but quite expensive and values are hard to duplicate without two or 3, Dale

[tysontom]

>Drew, I have had almost 0% problems with the original caps AR

>used. Others swear they have good results replaceing them.

>Also silver wire is discussed as a major improvement? Maybe

>use and volume levels through their life has damaged the caps?

>Solen is a good sub but quite expensive and values are hard to

>duplicate without two or 3, Dale

I agree with Dale: the original Chicago Industrial paper capacitors used by AR are rugged and long-lived. I have rebuilt many AR speakers and I really don't remember a single capacitor failure other than that caused by excessive input power or overload.

To digress a bit (and this has nothing to do with Chicago Industrial capacitors holding their value), in 1968 I had an AR-3a (of a stereo pair) indirectly struck by lightning. The woofer cone was pushed out beyond the pole piece, and the fiberglass caught on fire inside the cabinet, but the crossover network -- and those Chicago capacitors -- were not damaged even though the crossover wiring insulation was partially melted. The speaker wire to the Dynaco Mark III was badly scorched, and the amp was damaged, even though it was turned off! Incidentally, I put the woofer cone back in place and the speaker still worked. I sent this speaker back to AR with the lightning explanation, and they replaced the woofer anyway at no charge under AR's "Full Warranty." I still have these AR-3as, and they are playing in my office at this moment. I have pictures of this lightning damage somewhere.

--Tom Tyson

[Guest dogmeninreno]

Tom, That's an amazing testament. I think some luck was involved but if AR had not used the principal that you can hire a group of engineers to design a dam to hold back 10,000cf of water, I:E then they conclude that 90.2534 yards of concrete are required, 150 yards is what I would put in. Good ol "kis" ( keep it simple) principle Has worked for me in many many projects in the power production mfg field over the last 40 years. Thanks Tom, Dale

[soundminded]

Tom, better stop flying your sound system at the end of a kite during a thunderstrom. Next time try a key instead.

[ToastedAlmond]

That would've made a GREAT color advertisement in a stereo magazine! "Smoked up, scorched up, lightning-struck, AR-3a takes a lickin' and keeps on tickin'!"

[tysontom]

>That would've made a GREAT color advertisement in a stereo

>magazine! "Smoked up, scorched up, lightning-struck, AR-3a

>takes a lickin' and keeps on tickin'!"

Toasted,

At the time, 1968, I took pictures (which I will scan and try to send to Mark) of the AR-3a cabinet, the two tiny "burn holes" in the back of the 3a cabinet, the burned fiberglass inside the cabinet and the woofer itself, and I sent these pictures off to Roy Allison at AR. He was really amazed, and wanted to see the damage for himself.

The burn holes came about because the speaker (of a pair) was mounted on the wall on a shelf supported by "standards," and when lightning struck a tree outside my garage apartment, it then penetrated the wall, found a path to the wall standards screwed to the studwall, then through the back of the AR-3a and into the network, out the speaker wire and down into the Dynaco Mark III (turned off), through the grounded wall socket (the Mark III, however, used a two-wire power cord) to ground. I know there was a lot of current because the actual speaker wire was scorched and melted together all the way to the amplifier.

This pair of AR-3as still works fine today. The woofer was the Alnico version, since it just preceded the ceramic-ferrite woofer introduction. The cone of the woofer was pushed so hard that it caught on the outside of the pole piece and jammed. I slipped in back in the gap, but I think the woofer's suspension would have been stretched or damaged. It did seem to work fine afterwards, so at least the coil briefly withstood the lightning current. I think that the reason everything else in the speaker didn't go up in smoke is the nature of lightning -- basically a big burst of DC static voltage. But imagine the current level!

I also thought about the commercial aspect of such a testimonial, but I suppose that AR was not really interested in going in that direction. The company in the pre-Teledyne days was more interested in accuracy and basic reliability than boasting about lightning-proof AR-3as, I suppose. AR used a lot of testimonials in those days, but usually from musicians and conductors, etc.

--Tom Tyson

[Guest russwollman]

Ahem, not exactly AR's style, my boy, and rather sacrilegious, don't you think?

[ToastedAlmond]

I think it was on these very pages that was published a wonderful insight into how AR's lack of creativity in the advertising arena helped to lose its great market share to KLH and Advent in the late 60's early 70's.

I'm no sucker for advertising, but you get Miles Davis AND Leonard Bernstein showing off their AR based systems, THAT CAN STILL WORK AFTER THEY GET HIT BY LIGHTNING, and I for one am pretty much sold.

George

[tysontom]

> I think it was on these very pages that was published a

>wonderful insight into how AR's lack of creativity in the

>advertising arena helped to lose its great market share to KLH

>and Advent in the late 60's early 70's.

>

> I'm no sucker for advertising, but you get Miles Davis AND

>Leonard Bernstein showing off their AR based systems, THAT CAN

>STILL WORK AFTER THEY GET HIT BY LIGHTNING, and I for one am

>pretty much sold.

>

> George

Quite frankly, I don't think it crossed anyone's mind about an advertisement on the "Lightning-struck AR-3a" until well after the fact. In retrospect, it probably would have been a great advertisement, because AR also did some innovative ads on such things as "the return rate on the AR-2a is less than that of the carton in which it is shipped," or something to that effect, showing a row of AR-2a shipping cartons being rolled off onto the floor to test for strength. There were ads showing cardboard barrels of discarded drivers -- the "reject-drivers" that did not meet spec -- that were effective. Had Villchur been there at that time (he sold AR to Teledyne in 1967), he probably would have done something with it. Villchur wrote every single advertisement for AR from 1954 until 1966 or early 1967. His advertisements were the envy of the industry for many years with their candid, no-nonsense style. He used testimonials, but in a way to show that accuracy was the most important thing to this person or that, and that that individual chose AR speakers, etc. Never once did AR state that AR speakers were "the best," or "the finest" or whatever, and never was another manufacturer disparaged in those ads. Those ads are absolute "classics" by any standard in their day, but that type of magic wore off in the 80s and 90s.

Actually, AR's market share did not dwindle until late in the seventies. By 1965 AR had 32% of the entire domestic speaker market, the largest share ever by any manufacturer, at least during the times in which the Institute of High Fidelity kept records. KLH was never even close, but Advent approached these number in the early 70s. Bose quickly grew to prominence, but even today it probably does not have more than 5-6% share of the entire market since there are so many manufacturers out there.

--Tom Tyson

[Steve F]

As I’ve written about at great length in past Forum entries, AR certainly had their difficulties implementing the correct sales and marketing strategy as the stereo industry entered the baby-boomer college-craze expansion of the 1970’s. AR made so many fundamental marketing misreads with regard to advertising, product offerings, and sales policies that their abject collapse from 32% market share in 1966 to virtual insignificance by the 1980’s should be a required case study reading in every Graduate marketing program in the country. Never before has a consumer products company frittered away such significant technological advantages (acoustic suspension, the dome drivers, the "skip-proof" belt-drive turntable, etc.) in such a short period of time, going from industry leader to nothingness in less than 25 years. Amazing, and very sad.

As far as today’s market share is concerned, it’s a bit more difficult to identify. Product categories are not as clear-cut and well-defined as in the past, so a company’s "share" of the market is less easily discernable. A speaker company may make traditional freestanding ‘box’ speakers, but they may also make automotive speakers, in-wall ‘architectural’ speakers, on-wall ‘plasma TV ‘ speakers, all-weather outdoor speakers, self-powered speakers for use with a CD player or a computer, etc. Which of those categories should be added together when determining the total share of speaker market? See? It’s a lot more complicated than it was in 1964.

Having said all that, here is the way the speaker market lays out in 2002-2004:

Bose is the undisputed market leader. They have a far larger share than any other brand, approximately 15% of the total home speaker share.

Next up are the Harmon brands of Infinity/JBL.

Klipsch has come on very strong in the last few years, and can now be considered 3rd or 4th.

Boston Acoustics, Polk, and B&W are next, grouped very closely.

Definitive Technology has a significant, but smaller share.

Cambridge Soundworks sells a lot of product, but they do not report through the usual reporting channels, and their business is almost impossible to break out among their retail store sales, their Creative computer-related products, and their actual branded speaker sales.

Following them are the next 385 brands of speakers, some of whom have sales of as much as $10-20 million per year, down to the here-today, gone-tomorrow brands with sales of less than $1 million.

For AR to have had the market share that they did in the mid-60’s is nothing short of amazing, but their rapid fall to virtual obscurity demonstrates, once again, the fickle, fleeting, ‘what have you done for me lately’ nature of the consumer products business. Companies can’t rest on their laurels, and those that think their business is guaranteed and assured for years to come usually find out the hard way that nothing is guaranteed and assured.

Steve F.

[ar_pro]

Here's a take on AR's spot in the marketplace, from "Audio Alternative - The Definitive Guide To High Fidelity", published by Tobey/Dell in 1975:

[tysontom]

SteveF is exactly right here regarding AR's precipitous market-share fall, after dominating the speaker industry! The fall began in 1967 when the company was sold to Teledyne. Villchur was adamant about finding a buyer that (1) would retain key personnel for at least 5 years after the sale and (2) a company with a reputation for technical excellence. Teledyne agreed to those terms in the sale, and the aerospace corporation certainly met all criteria. For this reason, key people such as Roy Allison, Jerry Landau, Abe Hoffman and Sumner Bennett stayed on until 1972. Teledyne's problem, of course, was that it was run by bean counters, and AR began to suffer in sales even though profits were up. Once AR's good people left in 1972, the company began a steady decline. AR's most serious decline started in the late 1970s and into the 1980s.

Stereo Review and IHF had figures on market share, and some interesting figures:

1960 AR had 16.3% market share; JBL and E-V each had approximately 10.5%. By 1962 AR had 27.2%; by 1964 it had grown to 29.6%. In 1966, AR's biggest year, market share had grown to 32.3%, simply astonishing. KLH during this period had about 10% market share. AR's dominance in this industry was one reason that so many competitive manufacturers and dealers despised it, and AR products were routinely disparaged by competitors and dealers alike.

In 1968, however, the market share had dropped to 24.6% but rose again in 1969 to 27.8%. By 1973 AR's market share had declined to 12.5% and by 1978 it was down to 3.1%! Advent's market share was hovering around 8-9% and finally passed AR in 1974, but it, too, fell quickly after 1978. KLH was out of the picture by the early 1970s. Bose was up to 7.3% by 1977, and remained steady there for many years, gaining by default more market share as more loudspeaker manufacturers entered the market place.

--Tom Tyson

[ninohernes]

Why did Villchur want to sell AR?

[soundminded]

When I was a kid, we went to a dentist who gave out candy to his patients at the end of each visit. That's what you call creating new business.

As I recall, Vilcher went into the hearing aid business after he left AR. I always wondered how many of his hearing aid customers went deaf by listening to his speakers too loud for too long.

By the early to mid 1970s, it seemed every guy who could build a wooden box that didn't fall apart or get someone to build it for him went into the speaker manufacturing business. The home speaker building workshop became the new cottage industry in America. Most were dreadful. But every now and then, someone who knew what he was doing built something that created a company that lasted. Peter Snell was one of them. Also, companies like Cerwin Vega were able to cater to a segment of the market that wanted a particular type of product that had nothing to do with accuracy as in "high fidelity." Very expensive prestige products like Infinity and British imports like KEF started appearing on the American market too. That's when the whole hobby/industry started going to the dogs.

[tysontom]

>Why did Villchur want to sell AR?

There is a long answer to this question, but here's my wordy "short" answer.

Edgar Villchur was (and still is) a brilliant author, teacher and audio (and audiology) researcher. His education in electronics, physics and acoustics was largely self-taught, but he held a BS and MSEd from CCNY. This is probably why he was able to write about difficult principles with such clarity. If you have read his books or any of his many articles, you will quickly see why he is held in such high esteem for his writing skill. Before Acoustic Research he was able to support his family by writing for several publications, such as *Saturday Review* and numerous electronic journals.

Mr. Villchur was not an audio hobbiest as we are on this forum, but rather he thought often about the issues and problems in sound reproduction as he instructed an electronics course at NYU during the 1952-1957 period. It was during this time around 1953 that he began to understand the problems of, and to develope a solution for, bass-harmonic distortion so prevalent in the current speakers of the day. The patented acoustic-suspension loudspeaker was the result of this research, and this simple device "cut" rather than unraveled, the gordian knot, as Villchur used to say. The analogy of the gordian knot was that of speaker engineers for years trying in vain to reduce coloration and harmonic distortion in loudspeakers. The best way to describe Edgar Villchur's mind: he set about thoroughly defining and understanding the problems, and once that was done, the solutions would come fairly easily. Not all audio engineers go about research in this manner; many times products are developed for marketing purposes, and can in some cases be "solutions for which there are no problems."

In any event, Villchur did not want to go into business; he tried to sell his acoustic-suspension patent to two or three audio manufacturers (Altec-Lansing and Electro-Voice if I remember correctly), but they all refused to believe anything like that could be that good. When he presented the acoustic-suspension woofer idea to these speaker companies, the common reply was, "...you know, Ed, if something like what you describe existed, our engineers would have already discovered it by now." It was the common "not-invented-here" attitude among most all speaker companies through the years. Villchur, therefore, in conjuction with the late Henry Kloss (he was a student in Villchur's electronics class at NYU in 1953), finally gave in and formed Acoustic Research in spring/summer of 1954. The new company was incorporated in August, 1954. All during this time, however, Villchur was not happy as a businessman and industrialist; he'd rather be in research, and spent much time in his lab at home in New York developing such products as the dome direct-radiator tweeter, the AR turntable and so forth. And so by the mid-1960s Villchur and Abe Hoffman began looking for a suitable buyer that would preserve the values of AR (that is a topic all to itself) and help perpetuate the company into the future. Teledyne was the buyer in 1967. Villchur then went back to basic research, and he was able to develop many advances in hearing-aid technology that is in common use today. You know the rest of the story of AR after Teledyne.

--Tom Tyson

[ar_pro]

Tom Tyson wrote:

"In any event, Villchur did not want to go into business; he

tried to sell his acoustic-suspension patent to two or three

audio manufacturers (Altec-Lansing and Electro-Voice if I

remember correctly), but they all refused to believe anything

like that could be that good. When he presented the

acoustic-suspension woofer idea to these speaker companies,

the common reply was, "...you know, Ed, if something like what

you describe existed, our engineers would have already

discovered it by now."

I never knew that the acoustic suspension patent was offered for sale...that's amazing! If I recall correctly, didn't Altec manufacture a huge, cast-frame, true acoustic suspension, 15" woofer in the early '70s?

Thanks for the great information, Tom...we all appreciate your detailed knowledge of Acoustic Research.

[soundminded]

Shortly before he died several years ago, the founder of Sony, Akio Mauro was interviewed on television. Way back when (probably in the mid to late 1950s), he took the first pocket transistor radio to Longines of Switzerland to sell them the idea hoping they would be willing to market it. (They had special shirts made with slightly larger pockets because the originals didn't fit in a standard man's shirt pocket.) The executives at Longines told him the idea would never sell. It wasn't all that many years before Sony could have bought Longines with their spare change.

[tysontom]

Let me re-phrase part of what I said about the AR patent. Villchur had written the patent with full documentation, and it was in application with the US Patent Office at the time he went to visit the manufacturers. The design was fully documented, of course, but the patent had not been issued at the time, early in 1954, I believe, that he went to visit with those manufacturers. The patent was issued on December 25, 1956, and licencees later included KLH, Heath and Electro-Voice. It was E-V, however, that rankled the most over the patent, and its engineers decided to challenge the AR patent in an Indiana court citing a previous patent ("prior art") by Harry Olson. The very best description of this type thing was published by Harvard applied physics Professor Frederick V. Hunt in his book, *Electroacoustics,* in which he stated, "As is often the case with ideas that appear superficially to be simple, a good many loudspeaker designers discovered that they had already made this invention -- after someone else had pointed out what the invention was."

Having seen what happened to Col. Armstrong over the patent on the FM radio, Villchur decided that it was not worth the time and expense to defend it, since he was eventually going to release obligation for royalty payments anyway. He was actually pleased for others to use the acoustic-suspension design. The patent was left in place (though long-since expired) and was never dismissed, but infractions would be uninforceable. AR was also not going to be able to claim royalties, which they were going to discontinue anyway.

The Harry Olson patent, incidentally, was a design that was unrelated to acoustic-suspension design. It merely had a compliant suspension system, which lowered its free-air resonance (fs), which coincidentally made it appropriate for small boxes since the box (fc) resonance could be lowered. Conventional drivers (like the 55 Hz. Eminence guitar speaker we talked about elsewhere) were impractical in small boxes, as the box resonance (fc) in a sealed box would be much too high for decent low-bass output. Olson's design did not utilize a voice coil with long overhang, etc., and said nothing about reduced distortion or more uniform response, and did not have the electrical analogy as in Villchur's patent.

--Tom Tyson

[soundminded]

This Pioneer 12" acoustic suspension woofer is being offered by Parts Express. Any opinions about this for DIY projects?

http://www.partsexpress.com/pe/pshowdetl.c...tnumber=290-118

[Guest Brian_D]

Looks like a decent 12"... I would worry about it's upper range, most of the low-Q, low-resonance speakers have a mighty rough upper end.

Check out the speaker building forums for more info there...

[soundminded]

Most of the loudspeakers on that site are intended for ported or horn enclosures. This was one of the few 12" drivers specifically intended as an acoustic suspension driver. I wonder outside of its 8 ohm impedence how it compares with the AR 12" woofer.

I think either Tom or Ken said that all of the 12" AR woofers were the same but the AR9 has 2 in parallel and is still only 4 ohms and they are rated at 200 watts each, not 100 like the ones in the bookshelf units. While not a dead ringer, it seemed similar to me on first glance. After 50 years on the market, I'd expect somebody, somewhere to build one as good as the original.

[Guest Sean]

Drew: Outside of starting what has been a VERY informative thread, you've been phenomenally patient : )

When i pulled my AR 9's and 90's apart, i found that most of the caps had shifted value slightly, but not horribly. None the less, i decided to replace them with Solen's. Having said that, i would recommend other caps if price was not a major concern. One might also consider Axon brand caps, which are made in the same plant as the Solen's but sound slightly better. This is especially true of the higher voltage Axon's, which use solid copper leads.

While i can't say that the sonic changes that i heard were strictly related to the capacitor swap as i had also performed several other upgrades / circuit changes at the same time, the sound produced was much more open and spacious sounding.

To be quite honest, most AR's are somewhat soft up top and elevated in the lower mids / upper bass, which is referred to as being "warm" sounding. From what i can tell, i would attribute a substantial portion of AR's tonal balance to the caps that they used. Then again, the caps that were in my 9's and 90's were probably significantly different than what you are describing, so we are kind of comparing apples to oranges here.

None the less, i would either replace the cap with a newer, high grade unit OR keep the old cap and bypass it with a newer, high grade unit to achieve the proper rating. Personally, i would go with the first approach, but i have no idea what you're specific financial concerns are with this project.

As a side note, the Solen caps, which are available at Parts Express, are measurably superior to the Parts Express "Dayton" caps that they offer. As such, if you were going to order from PE, spend the extra money and get the Solens. Sean

>

[rrcrain]

I found the caps in my AR90s to be in a similar state. A bit off, but within tolerance value wise. They leaked rather badly though with the electrolytics leaking the worst. Replacing all of the caps with poly caps brought the bass back in line and restored the upper end of the spectrum as well.

[Guest litekeys]

I have rebuilt and/or canabalized a lot of AR's (and KLH's and Avents) and have found the Chicago Caps to be among the better ones Kloss used.

However, my dissections of them showed a very losely wrapped (read inefficient by today's standards) paper and foil construction in which the Kraft seems to dessicate of the oil impregation when the wax (inevitably) cracks.

I have measured several of these for accuracy and dissipation factor. They all seem to read about 10 percent high (as you note--for example 20 uf CIC caps on the AR4 consistently read about 22 uf) which tends to be more characteristic of electrolytics than films--electrolytics tend to run on the high side of the +/- tolerance and films tend to be on the low side (which figures when you consider the costs of manufacturing).

Anyhow, the Chicago caps consistently show a DF of about 0.03. This is about what you get with a good NPE cap (the value is that they dont seem to drift so much, nor do they leak and fail like NPE's). By comparison the black and red Temple bran NPE's Kloss used in the KLH's are about the best built NPE's I have seen and they too run about 0.03, which again is good for this type of cap. [i would be very very wary of the oil filled cans in the very old AR's--they could contain toxic DBCP's, a liability little know at the time of manyfacture).

Bottom line: these Chicago's (like the Temples) are way way inferior to any film cap, whether polyethelene (Mylar), polycarbonate, or polyproplyene. Just about any film cap, even the cheapest ones, will have a DF of 0.005 or better, and this is a difference one can hear.

Not sure why Kloss took the cheap road so often on tweeters and caps, when he pay so much attention to the woofers. But in all cases, for a couple of buck you can replace these caps with any kind of film cap for a real improvement.

LM

>I took the cardboard off of a spare Chicago Industrial Cap

>(6mfd) from a AR2 and found it to be film and foil in wax.

>

>This is like some very expensive modern caps. It seems to me

>that these would be better than the Solen film types that many

>people use as an upgrade. It alse seems that this type of cap

>would have an unlimited lifespan unlike electrolytics.

>

>My only question mark is that they measure 8mfd not 6mfd.

>Would the value increase over time?

>

>Is my thinking right to reuse these or would I get a better

>result from the Solen's?

>

>Thanks,

>

>Drew