snhirsch Posted October 13, 2017 Report Share Posted October 13, 2017 I have a very early AR1 that belonged to my father, Julian Hirsch - have posted here before about the unit. Finally got around to putting it on the bench and taking a closer look. It appears to be fully operational, but I'm scratching my head over the (7) binding posts on the rear connection plate. The instruction sheet is not intact enough to get the full picture and I cannot seem to find any information on line. Does anyone have a good photo or PDF of the connection information? This particular unit is serial # 147 and was hand-delivered by Henry Kloss in 1954 or 55. It has a custom modification to allow use as either an AR1-W or with Jantzen tweeter - as explained in a little note from Henry that still survives. Link to comment Share on other sites More sharing options...
genek Posted October 13, 2017 Report Share Posted October 13, 2017 Here you go. Link to comment Share on other sites More sharing options...
snhirsch Posted October 13, 2017 Author Report Share Posted October 13, 2017 Thanks so much! I'm amazed this device is still operational after 62 years. I swept the woofer at about 5 watts input and it rattled shelves in the shop below 50 Hz. Link to comment Share on other sites More sharing options...
JeffS Posted October 15, 2017 Report Share Posted October 15, 2017 If memory serves, your father took this speaker out of storage to compare it to the AR-303 when he reviewed it back in 1995, and commented on how it shared similar woofer performance with the then new 303. It's great to hear that it still works well after all these years. Another, likely unique, feature of your cabinet is the three separate holes that were drilled for the woofer only connection. Later versions brought the three holes together. The included pictures are from serial #196 (from an online auction). I love the hand assembled aspect of these very early cabinets, with one of the company founders probably grabbing the corded Black and Decker drill to punch these holes through. Link to comment Share on other sites More sharing options...
snhirsch Posted October 15, 2017 Author Report Share Posted October 15, 2017 That's a bit different from the hole pattern on mine, but same idea. There is a little confusion as to which terminals should be jumpered for full range operation on mine. The terminals are labeled in pen as A, "D" and C (looks like my Dad's handwriting), but I'm thinking the D was supposed to be B. The arrangement shown in your photo would probably not be correct on my unit. I'm going to proceed carefully to avoid damaging the tweeter. My speaker shows the same slight separation between the rear panel and the top and bottom as seen in the above photo. I believe that's a result of the rear panel shrinking over the decades. In any event, it doesn't vent the inside of the cabinet nor cause any apparent resonance. Does anyone on the forum have input on this? Is it worth trying to flow glue in that little crack and clamp the top and bottom down? My experiences with vintage electric guitars suggest it's probably best not to mess with it. Opinions? Link to comment Share on other sites More sharing options...
ligs Posted October 15, 2017 Report Share Posted October 15, 2017 Mine works with the rear panel like this. The amp goes to 3 and 4 . There is a red jumper wire goes between 1 and 2. See the picture attached. George Link to comment Share on other sites More sharing options...
snhirsch Posted October 15, 2017 Author Report Share Posted October 15, 2017 That's not quite the same as mine. See photo below (Henry's signature still survives in the lower right). The speaker seems fully operational! I should add that I'm finally prepared to sell the unit. I would rather have it live out it's days in the hands of an enthusiast than languishing in storage. Link to comment Share on other sites More sharing options...
ligs Posted October 15, 2017 Report Share Posted October 15, 2017 Good luck to you! Link to comment Share on other sites More sharing options...
genek Posted October 15, 2017 Report Share Posted October 15, 2017 The Audio League review of the AR-1 was published in Nov of 1956, and presumably they had the use of one for some time prior to its release. So perhaps this was an early or pre-production unit that AR loaned to the Audio League for testing in '54 or '55. Link to comment Share on other sites More sharing options...
snhirsch Posted October 15, 2017 Author Report Share Posted October 15, 2017 Yes, that's exactly what it is. No mystery there. I have all the Audio League report folders and correspondence. This speaker almost certainly took part in the original "Live vs. Recorded" demonstration. My father, Mr. Houck and a few others presented a program where a bank of AR-1 speakers playing a tape of a pipe organ was A-B'ed against a live organist. Tom Dowd of Atlantic Records assisted in the reference recording and quite a lot technical preparation went into the event. Link to comment Share on other sites More sharing options...
genek Posted October 15, 2017 Report Share Posted October 15, 2017 Talk about provenance. Sounds like a real museum piece. Can you shoot a bunch of pictures so we can upload them to the library here? Link to comment Share on other sites More sharing options...
snhirsch Posted October 15, 2017 Author Report Share Posted October 15, 2017 I thought I had previously uploaded some photos, but will be glad post a new round. Would be interested in feedback about: 1. Tiny separation between rear panel and top / bottom of enclosure. Do I try to fix this? If so, how? Flow in glue and clamp? Leave it alone? Other? 2. Small mildew spots on grill cloth. What will take them out? I thought about white vinegar but would be good to hear from folks with more experience. Based on the photo of an auction piece, I'm betting many (if not all) speakers of this vintage have a slight shrinkage of the rear panel. The way the enclosure is built, this shrinkage pulls in the sides (long area of contact) and eventually causes the top and bottom to bow out by a few thousandths. Link to comment Share on other sites More sharing options...
genek Posted October 15, 2017 Report Share Posted October 15, 2017 Considering the provenance of the piece, I'd fill the gap with something non-permanent that won't have the potential to reduce collector value. Non-hardening window caulk, or maybe paraffin. Photos of the grills will help with the best recommendation for treatment. Link to comment Share on other sites More sharing options...
snhirsch Posted October 15, 2017 Author Report Share Posted October 15, 2017 Here's a few more photos. One is a closeup of the panel separation. Looks like the Grand Canyon in a close-up, but is actually small enough that you'd have trouble getting wood glue to flow into it. The paraffin idea has some merit, but I'm not going to dive into anything. The grillcloth closeup shows the mildew spotting (also visible on the rear connector plate). Notice the "boomerang" shaped jumper for tweeter level. Looks to be cut from thin copper stock by hand with a pair of tin snips! This speaker is likely one tiny step from a manufacturing prototype. Link to comment Share on other sites More sharing options...
Glitch Posted October 15, 2017 Report Share Posted October 15, 2017 Regarding the "crack"... Can you tell what kind of joint was used to construct the cabinet? If it was a butt joint, I could see the need to seal it if one wanted to restore the speaker performance. In this case, I would consider applying some sort of reversible sealant to the seam on the INSIDE of the cabinet. Possibly something as simple as a tape with a "not too aggressive" adhesive. If the joint is a rabbet joint, it may not be leaking. Regardless, filling the seam from the outside would seem to be a measure of last resort. Link to comment Share on other sites More sharing options...
snhirsch Posted October 16, 2017 Author Report Share Posted October 16, 2017 I don't know anything about the AR-1 cabinet construction and am loathe to disassemble the unit. The joint isn't obviously leaking, but you can feel more vibration at that point when under high drive levels. There is no audible buzzing or resonance that I'm able to detect. I'm probably going to offer the unit "as is" and let the next owner decide if it's something they want to mess with. Link to comment Share on other sites More sharing options...
stupidhead Posted October 16, 2017 Report Share Posted October 16, 2017 that crack is suspect for sure. obviously a look inside is the only way visually to tell if the entire seem is breeched. possibly a set of stethoscopes could be used to detect any sound loss from there? love the grille cloth on this for sure. there should be a museum for this kind of stuff. Link to comment Share on other sites More sharing options...
Glitch Posted October 16, 2017 Report Share Posted October 16, 2017 To determine the joint type you could insert a thin wire or Exacto blade into the crack and see how deep it is. If it stops after half of the thickness of the back panel (3/8") then the joint is most likely a blind rabbet. If it goes in the full thickness of the back panel (3/4") then it is a butt joint. I've had success with using a syringe with a fine needle (as small as 30 ga.) to inject glue into the joint and clamp for this kind of repair. Once clamped, any excess glue can be wiped off while it it still wet. The risk of this is if the glue doesn't hold then it makes it even more difficult to repair. I understand your reluctance to open up the cabinets. Personally, I would prefer to purchase the speakers "as is" and make the repairs to my own specifications or desires. Thanks for posting the pictures and story of this speaker. It is cool to know that things like that are still out there. Link to comment Share on other sites More sharing options...
snhirsch Posted October 16, 2017 Author Report Share Posted October 16, 2017 It appears to be a blind rabbet. Using a piece of card stock as a feeler gauge, it stops at 3/8". I'm going to talk to a couple of high-end cabinet makers in the area and see what they recommend. Clamping the unit would entail considerable pressure and I'd be very concerned about the stress loosening a corner joint and making a bad situation worse. Link to comment Share on other sites More sharing options...
ra.ra Posted October 16, 2017 Report Share Posted October 16, 2017 Thanks for sharing the story of this historic speaker, and the detailed pics are terrific. Like others, I think it's a good idea not to try to repair crack. Not much else to add here, but it's interesting to note that the earliest AR-1's shown here (#147 and 196) have the labels with the Mt. Auburn St. address, which I believe was Kloss' loft studio near Harvard Square. And the label for the unfinished AR-1W (#3791) posted by genek shows the short-lived address at 25 Thorndike, probably the first move to a more light industrial space. Sort of curious, though, that the AR-1W label included instructions for high frequency performance when it only contained the single woofer driver. Looks to me like the OP's speaker has its boomerang set to increased HF output (3,4,5), whereas ligs has his set for normal HF output (4,5,6). In the final post of the link attached, there is some suggestion for AR-1 cleaning grille fabric, but unfortunately the pics are no longer available so you will not now which fabric was being discussed. I have seen that grille fabric with swirls in pics of AR-1's before, and the pic shown here looks like it may have been from an ad or product literature. Link to comment Share on other sites More sharing options...
genek Posted October 16, 2017 Report Share Posted October 16, 2017 5 hours ago, snhirsch said: It appears to be a blind rabbet. Using a piece of card stock as a feeler gauge, it stops at 3/8". That being the case, your cabinet is in no danger of coming apart, and your only real concern is whether the back is loose and there's an air leak that can adversely affect woofer performance. Easiest way to test for that is to cover the back seam with some blue painter's tape (get the plastic stuff from 3M, it's nonporous) and see if that makes any difference in the sound. If it does, just push in some non-hardening window caulk that can easily be removed (grey ropey stuff that comes in rolls); it it doesn't, you can leave it be. WRT the grille, try brushing one of those mildew spots with a dry toothbrush to see if there's still color underneath. One of the unfortunate things that mildew does is eat organic dyes, so there's a good chance that the fabric has been permanently discolored. Link to comment Share on other sites More sharing options...
snhirsch Posted October 16, 2017 Author Report Share Posted October 16, 2017 Good call on the spots. I lightly rubbed one near the edge and the mildew flaked off - leaving a slightly bleached out region. Link to comment Share on other sites More sharing options...
genek Posted October 16, 2017 Report Share Posted October 16, 2017 Is the white squiggle pattern just a different color region of fabric, or is it something like paint that was drizzled onto the dark fabric? If it's the latter, you may be able to recolor the fabric. If the former, you're probably SOL for restoring it. Link to comment Share on other sites More sharing options...
JeffS Posted October 17, 2017 Report Share Posted October 17, 2017 11 hours ago, snhirsch said: It appears to be a blind rabbet. Using a piece of card stock as a feeler gauge, it stops at 3/8". I'm going to talk to a couple of high-end cabinet makers in the area and see what they recommend. Clamping the unit would entail considerable pressure and I'd be very concerned about the stress loosening a corner joint and making a bad situation worse. The cracks may partly be a fit and finish issue from initial production, and it looks like the solution was to use a crack filler. I've included a couple of pictures of the rear of my AR-1W that has a white (possibly caulk) substance used to fill the cracks around the perimeter of the rear panel. Another picture from an online auction (sn 19671) illustrates the same treatment. There are other examples I've seen online so I think it's a safe bet that this was done at the factory, and your speaker simply predates this procedure. The caulk gun may not have been too far away from the ash tray. Link to comment Share on other sites More sharing options...
snhirsch Posted October 17, 2017 Author Report Share Posted October 17, 2017 Heh. The cigar ashes might have been a critical ingredient of the "secret sauce" used to caulk the enclosure. Link to comment Share on other sites More sharing options...
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