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ra.ra

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Everything posted by ra.ra

  1. Just to be clear - - am no expert on this - - in fact, have never seen this model of speaker or that particular circuit board, but the assembly is a bit of a mystery. My guess here is that the L-pads are anchored to the PCB, and then their stems are poked thru the rear cabinet panel and secured again. Conversely, I think the terminal posts are secured to the Masonite, and then their stems are poked thru the PCB and nutted again. Just a guess, but it sounds feasible. In your most recent pic, it looks like foam pads at the corners achieve the clearance under the PCB.
  2. The attachment of the PCB is the real mystery here. Apart from the four nuts (one per terminal) visible in these pics, there are four blobs of hot melt holding the corners of the circuit board in place. I would assume that there is at least 1/4" space between the backside of the PCB and the Masonite panel and that in this void space there is a substantial lock nut (and washer) to structurally secure the binding post, and there might also be small stand-offs for the L-pad shafts, too. Is it possible that the PCB might easily lift up after: removing other two visible interior nuts; removing L-pad knobs and outer nuts; and slicing though hot glue?
  3. Beautiful speakers. Oak cabinets!!!....you don't see that every day with AR's.
  4. That's a great post, ar_pro, and I totally agree about this overall line of Crown amplifiers. The SL-2 (or the professional PSL-2) is a pre-amp which has been on my radar for some time, but prices have really escalated in recent years. The power amps you mentioned would all be perfect complements, and if you listen to FM broadcast like I do, throw in a Crown FM-3 for a very fine component system. Just my $0.02, but as much as I admire the front and rear panel layouts of these excellent components, I've never cared for the wood casings that Crown offered as a factory option. I know they add "desirability" in the used market, and possibly even some added WAF, but they seem a bit over-scaled and clunky IMO. But I do agree: Lou's PL amp in oak cabinet looks terrific.
  5. Hello Andrew. This post might've been slightly more appropriate in the For Sale section of this forum, and you will probably benefit by providing additional information on your orphan speaker. But more specifically, pics will be necessary to generate interest for any potential buyer, and some indication of your location and price range will be equally important to conduct a successful transaction. With the Mini-III speaker model, pics of front and rear and cabinet sides are all important. Early Rectilinears used very nice walnut veneer, and this is always critical to buyers. They also used more than one grille cloth color, and there were minor variations in the driver assemblies and placement - - you should show grille material and front view of speaker without grille. Also a pic of backside will reveal the type of cabinet construction employed as well as the location of wire terminals and factory labels. These are great small speakers, but the minor variations throughout production will probably be important to anyone seeking to complete a pair of Mini-III's.
  6. The crossover pic you showed on p.2 of this thread is the later 2ax with the same woofer and tweeter as your speakers, and you can see that the colored wiring is consistent with these schematics - - - i.e., opposite polarity for woofer. Your crossover assembly work appears top-notch, but I have no experience with those particular cap components, and the issue of bypass caps will be met with equal measures of enthusiasm, skepticism, and scorn. Some will praise the resultant synergistic balance and airy brilliance; others will claim that "it can't hurt"; and still another crowd will refer to this practice as claptrap, rubbish, bunk, hogwash, poppycock, or flapdoodle. You're having fun and doing great work and that's what matters - - - I am sure you'll get these speakers sounding as good as they are already looking. Keep it up and report back.
  7. Thanks for both responses. I am aware of the coil used with this replacement driver, but perhaps I have not been following all of the latest thoughts regarding the best cap value for the Hi-Vi install, and my confusion was trying to understand which configuration der had adopted for his 3a project. I know RoyC has continued to share his evolving recommendations on this matter, to which we are all grateful.
  8. Re-coning is a reasonably involved process often required due to significant damage to a driver, whereas re-foaming is relatively simple and essentially a form of periodic maintenance. I assume your work refers to re-foaming here. There seem to be a number of versions of the AR-93, so it would be helpful here if you could document the particular model you have. Noting part numbers for the 8-inch drivers and details of the crossover might be very useful. Also, it is easy to add pics to your thread (100kb jpeg files are more than satisfactory), and that is always appreciated in this forum as well as helpful for your project. AR-9 series?........are we talking about the same family of tweeters? I think the pic attached below is the p/n 038 tweeter that the OP has mentioned - - - this has a 3-1/2" dia. faceplate and a 2-3/8" dia. magnet. Now I recall your project after seeing this thread again - - I don't believe you had any AR drivers at all left in those speakers, is that correct?
  9. Hi der, I always enjoy reading your posts, but I cannot understand exactly what you are saying here for the third time. Earlier, you mentioned having some 6.2uF caps - - - are you saying your new tweeter circuits have no cap at all, or simply that you have not replaced the old cap with a new cap? Which type of original caps do (did) your 3a's have for the tweeter, and have you evaluated them in any way?
  10. Your work on the cabinets looks terrific, and the re-foam appears very good, too. For comparative purposes only, I am including another good 2ax schematic with a few comments: this diagram was made to document earlier version with cloth woofer and phenolic tweeter see Note 1 - - 2ax woofer is meant to have opposite polarity from mid-tweet wiring see Note 3 - - it appears that someone else has encountered a series resistor on the mid (+) terminal - - this would not "increase output of tweeter", but rather would tame the midrange a bit to alter the output balance between these two smaller drivers in order to avoid the tight fit of multiple wires into a female mini-spade at the L-pad, the alternate location for the resistor is to solder directly across the rear terminals on the tweeter, as was recommended in the previous post which provided the first 2ax schematic I'd be curious to know in greater detail what you are using to create multi-cap values of 4uF and 6uF. Also, in case I overlooked it, what material are you using for the new crossover panel that is so glossy? Thx.
  11. Brownie, am not sure what you're saying here - - - upgrade? - - - are your tweeters non-functional, or are you dissatisfied with the originals? Everyone's entitled to an opinion, but I find this statement perplexing, too. I think this family of 1-1/4" tweeters are terrific, and AR engineers must have found them quite satisfactory as well since versions of this tweeter found their way into at least a dozen speaker models over a number of years.
  12. This pic using foreign pots is from the thread I tagged earlier, which makes no mention of altering the original attachment plate.
  13. Take a look at this current thread which uses robust foreign pots which are about 1-3/8" diameter.
  14. I had meant to comment earlier to say how nice this new circuit work has been done. Also, I admire the use of those truss-head screws for fastening the new panel, and I really appreciate your sharing the specific switch product that was used. I get all confused trying to translate the schematic to the actual switch terminals, and your pics are helpful at getting a better understanding of this arrangement.
  15. Yes, that is a very good schematic diagram and I wish I could remember who produced it and shared it for common use. It appears to be very current, since it shows the resistor only on the mid but not on the tweeter. And while I do like those slender, robust green resistors, I neglected to mention that I think these are not available in the 25-ohm value, so I am pleased that Roy has clarified the need to adhere to this value for "original" replication.
  16. I like using the thin green resistors made by Jantzen, Mundorf, and Lynk, and because of their length and ample lead wires, my own preference would be to install it directly to the backside of the driver and solder in place. Not sure who provided this diagram, but the attached schematic clearly shows how the added resistor could be located either at the L-pad or on the driver.
  17. Hey, those are my 2ax speakers which were re-built almost 7-1/2 years ago! Thx for sharing. Not sure what happened to my post (now showing up as blank ?) from last Wednesday, but your progress since then is very impressive. My previous comments were meant to state that classic AR speakers were generally not sold as "pairs", and that the several minor differences that you have uncovered should not be considered particularly unusual. Most likely, these two speakers were assembled during different batch runs several weeks apart, and the minor differentiations simply reflect components which were obtained from different sources. I was a bit surprised to see two different materials used for cabinet stuffing, but that multi-colored material was found in many Euro AR's and is original. For the sake of consistency, my inclination would probably be to replace both speakers with new fiberglass, which according to AR assembly drawing for the 2ax, should be 27 ounces per cabinet. You are receiving plenty of good advice here, and your cabinet refinishing work looks terrific. No expert here, but I've often thought that the walnut veneer found on the Euro-produced cabinets has distinct differences from the walnut cabinets manufactured in the U.S. - - - could this simply reflect the distinctions between American Walnut and English Walnut species?
  18. Apologies for off topic comment, but on the following page in that 1976 Stereo Review issue was the introduction of this new product.
  19. Excellent pics, and it's good to know that all drivers are functioning. Wow, I'm not sure what was intended by hacking away half of that crossover panel, but that obviously now becomes a top priority. The multi-colored stuffing is fairly typical for AR's assembled in Europe, but it is surprising to see two different materials used in this pair. Your best bet would be to discard both and replace with equal amounts of new fiberglass (27 ounces per cabinet according to the AR factory drawing). New foam surrounds are essential, and woofers would also benefit from new perimeter seals when re-installing. New L-pads are a good idea, but you really should make the effort to replace the old capacitors as Kent originally recommended. Clearly you wish to install banana terminals, but I would strongly discourage you from placing the L-pads outside of this original recessed circular cut-out which is intended to fit all of these components. I think you should just fabricate a new closure panel to cover this hole, and arrange your new terminals and L-pads within this circle. Also to this end, you will want the L-pads that have stems which will not protrude beyond the rear panel surface. This will allow the speakers to be placed flat on their backs.
  20. That's a great first post and wonderful testimonial. Welcome to the forum.
  21. Hello powerglide, and welcome to the forum. You've got a fine-looking pair of 2ax speakers that appear almost brand new. Your photos are very good, but I suspect they are still rather large image files, since it took a few moments for them to load for viewing (for future: 100KB file size is more than adequate). Kent hit on all of the most salient points with good advice and recommendations. The decision regarding original pot replacement will be based on your own diagnosis of their condition and functionality... and personal priority, of course. Same with capacitors - - the 2ax typically uses one 4uF and one 6uF cap per cabinet, and yours just might employ the colorful Sprague Compulytic can-type caps which may not require replacement. For confirmation, these can be measured with a hand-held meter, if removed from circuit. Replacing speaker terminals is also a personal preference - - I find the original knurled nuts to be very robust and quite good and have been very satisfied by using spade or ring terminals on my speaker wires (see pic). Other members here have documented clever methods for keeping the original terminals yet adapting them for use with banana plugs. Your speakers do reflect the "Euro" cabinet styling with thin front edge profile, larger grille area, and brown speckle paint on backside. Also, while AR's main facility had already moved to Norwood, your label suggests these were most likely assembled in the Holland facility. For reference, I've also included a montage pic of speakers nearly identical to yours: these speakers were assembled in the England facility, and the stamp on the woofer magnet indicates it was fabricated in 1974. With a re-foam, your woofers should be good for many years to come - - - you may want to re-install them at 180° from original position to counteract the possibility of spider sag. The "ugly duckling" mid drivers are extremely reliable and seem to have a very low failure rate and generally require no attention. It is the tweeters in these speakers that are known to degrade over time - - you'll want to make your own assessment of their performance, but from appearance only, the three orange suspension blobs appear to be surprisingly "fresh", which might be an indication of their overall healthy condition.
  22. I suppose glue is possible here, but I'm thinking they are probably stapled. The AR-2 is such an early speaker model, and I think the grille attachment possibly pre-dates the use of adhesives for this purpose. AR-2's also used that wonderful speckle-tweedy grille cloth, which makes visual location of the tiny staples even more of a challenge. The drywall screw option is a very clever and useful technique, but it will not be sufficient if staples have been used. If staples are present, you will benefit from the use of a mild magnifier to locate the staples as well as a couple of strong but delicate tools to begin to extract them. Dental pick, tiny screwdriver, needle nose pliers....these are very successful for staple removal without damaging the original (and non-replaceable) grill cloth.
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