Unusual AR-7's

[ra.ra]

Have been meaning to ask about this for several months, but I just came across this image again so here it is. Late last winter, I made a half-hearted, unsuccessful effort to procure this unique pair of AR-7's from the second owner who had purchased them at a church rummage sale. (Owner 1, owner 2, and myself are all located in metro Boston area.)

No further information on these other than what I report here and what shows up in the attached pics, but I have never seen an AR-7 with a pot control or the three screw terminals. My first guess was that maybe these were a prototype, but I'm also inclined to think perhaps they were a custom order (by an AR employee?). Real wood veneer cabinets, but the owner was unwilling to remove grilles for pics of drivers. At first, I thought both serial numbers read something like 140145, but as it turns out, both speakers had a sloped handwritten note here which spelled N-O-N-E.

Any thoughts on this interesting permutation?

[KlausDK]

Interesting, especially the "NONE" at the serial numbers. Could be an AR-6 crossover mounted in an AR 7 speaker, since they used same drivers.

Real wood veneer suggests an early version of AR-7, at least in Europe, the AR 7 enclosures fast turned to Vinyl "veneer"

If grilles have not been removed yet, now would be a good time to do it, surrounds are propably long gone, and with further use, the woofer might get damaged beyond repair.

BRgds Klaus

PS: did you see my PM from July?

[Sonnar]

Yesterday a friend of mine bought this beautiful pair of AR 6 . There is a pot instead of classic switch selector, and three screws terminal like AR 3a. it' s not unusual?

[owlsplace]

AR 6-1.jpgAR 6-3.jpgAR 6 - 2.jpg Yesterday a friend of mine bought this beautiful pair of AR 6 . There is a pot instead of classic switch selector, and three screws terminal like AR 3a. it' s not unusual?

The early ones had pots -- two of my three pair have them.

Roger

[ra.ra]

Klaus: I suspect you may be correct that these odd AR-7's may have a crossover very similar to the early AR-6's (with coils, etc.), but we shall have to remain in a speculative state since I do not actually own this pair of speakers . I had been unaware that the dreaded vinyl cabs had infected the Euro market, too - - - somehow I thought that attempts to import those cabinets into Europe were confiscated at customs in England and Holland . On these shores, we envy the number of teak-veneered AR's that show up occasionally on your continent.

Sonnar: those AR-6's appear all original (except new foam), and it's great to see them sitting on another pair of classic AR's (2ax?) with that thin front edge profile on the cabinets. I may be mistaken, but I think it's rather rare to see Euro AR-6's with pots and front-wired tweeters. A few of the CSP members who know the international versions best are Klaus (Denmark), Rlowe (Australia) and RobHolt (England). Attached pic shows what I tend to think of as typical Euro AR-6 model.

Roger: returning to the topic of AR-7's, I kinda like that you just stripped the vinyl off your pair and let the MDF be 'authentic'. You have actually committed what I have only considered to do to some AR-18B's.

[owlsplace]

Klaus: I suspect you may be correct that these odd AR-7's may have a crossover very similar to the early AR-6's (with coils, etc.), but we shall have to remain in a speculative state since I do not actually own this pair of speakers . I had been unaware that the dreaded vinyl cabs had infected the Euro market, too - - - somehow I thought that attempts to import those cabinets into Europe were confiscated at customs in England and Holland . On these shores, we envy the number of teak-veneered AR's that show up occasionally on your continent.

Sonnar: those AR-6's appear all original (except new foam), and it's great to see them sitting on another pair of classic AR's (2ax?) with that thin front edge profile on the cabinets. I may be mistaken, but I think it's rather rare to see Euro AR-6's with pots and front-wired tweeters. A few of the CSP members who know the international versions best are Klaus (Denmark), Rlowe (Australia) and RobHolt (England). Attached pic shows what I tend to think of as typical Euro AR-6 model.

Roger: returning to the topic of AR-7's, I kinda like that you just stripped the vinyl off your pair and let the MDF be 'authentic'. You have actually committed what I have only considered to do to some AR-18B's.

Euro AR-6.jpg

One of my Euro 6's has a front wired tweeter and two have pots.

There is a pair of mahogony 7's on te auction site at the moment but I don't have the spare change.

My 7's will get some veneer. I'm thinking Koa at the moment for sentimental reasons. That is if I don't run out of time first ...

Roger

[Sonnar]

ra.ra : my friend' s AR 6 are sitting on a pair of European late AR 3a , both are made in Amersfoort, Holland. It' s the first time I see European AR 6 with pots and three screws input, while front-wired are more common. Last year appeared on ebay.it a pair of very early American made AR 6 with a bit larger molding front than European version, with woofers cones very similar to KLH 32 .

[tysontom]

Have been meaning to ask about this for several months, but I just came across this image again so here it is. Late last winter, I made a half-hearted, unsuccessful effort to procure this unique pair of AR-7's from the second owner who had purchased them at a church rummage sale. (Owner 1, owner 2, and myself are all located in metro Boston area.)

No further information on these other than what I report here and what shows up in the attached pics, but I have never seen an AR-7 with a pot control or the three screw terminals. My first guess was that maybe these were a prototype, but I'm also inclined to think perhaps they were a custom order (by an AR employee?). Real wood veneer cabinets, but the owner was unwilling to remove grilles for pics of drivers. At first, I thought both serial numbers read something like 140145, but as it turns out, both speakers had a sloped handwritten note here which spelled N-O-N-E.

Any thoughts on this interesting permutation?

AR7.jpg

Those AR-7s are definitely very early prototypes or test versions, not production models. Note that (1) there is no serial number, (2) the cabinet is made from plywood with veneer covering rather than MDF and (3) the input-terminal strip has the three-terminal input ("woofer-only") with level control, probably usurped from another AR model, perhaps an AR-2x or equivalent. I think all of the AR-7s came with the capacitor only in the crossover with no coil, but this one may have been an exception. Insofar as these were in the Boston area, it is likely that they slipped into someone's hands from the factory and were later sold or what have you. As for real-wood veneer, AR did offer the AR-7 in "walnut-stained" birch veneer, but soon after the speaker was supplied in vinyl-clad veneer. Wood versions are less-frequently seen these days, but they are not rare particularly. Another reason that AR went to the switch and didn't use the level control has to do with the thickness of the AR-7 wood panels. They are not 3/4-inch panels, so the level control knob or shaft protrudes slightly beyond the back of the cabinet.

This would be a very unusual collectible AR-7 pair. It's probably not the very first pair, but they would be at least among the test or prototype AR-7s built in late 1972 before AR moved its facilities to Norwood (1973). Once things were in Norwood, the level controls largely went away, along with the hot glue holding the grill panels in place. My guess is that this pair was a Cambridge pair, very early test speakers. I wish you could buy them from that owner.

--Tom Tyson

[ra.ra]

Thanks for the response, Tom - - - not sure how I overlooked this post more than a week ago.

Your suspicions seem to confirm my thoughts about this pair of AR-7's, and I'd be very interested to see how these were put together and how they perform. They appeared to be extremely unique and in great condition. Unfortunately, they have ended up in someone else's possession and we'll probably never get to the bottom of this mystery. The sale occurred at a time when I was rather busy with other matters and our metro area was strangled by several successive massive snowstorms which made daily travel extremely difficult. Nonetheless, since the seller was only two towns away, I did attempt to get him to allow me to come inspect the speakers in person, but my powers of persuasion were apparently insufficient, and soon therefafter they had slipped away to places unknown.

It is interesting when these rare odd specimens turn up from time to time, but it certainly is disappointing when their lineage cannot be explored, theorized, and debated on these pages.

[RobHolt]

Very interesting indeed.
FWIW I have AR6 crossovers installed into my 7s and the response is much better.

Vocals in particular sound more natural with the rising top end of bass driver rolled down.

Undoubtedly the very simple cap only crossover in the 7 is due to cost restrictions.

[ra.ra]

Rob - - Yes, I do remember this idea of yours (thread below), but you never did share the specific components of your crossover build or the subjective or measured results of the completed project. I was very interested since even the AR-6 "B" version crossover is far more complex than the standard AR-7 crossover. Much appreciated if you can show pics of the crossover you installed. Thanks.

http://www.classicspeakerpages.net/IP.Board/index.php?showtopic=8300&hl=