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ra.ra

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About ra.ra

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  1. Hello.

    I buy an beautiful Acoustic Research AR- 4xa speakers pair and i wish to recap the crossover. I not open the cabinet yet, but i wish to buy from Mouser some pieces for recapping my amplifier and i intend to buy with this ocassion the capacitors from my speakers. I wish to tell me what pieces is necesarry for my crossover. 

    Thank you. 

  2. ra.ra

    AR2 Tweeter

    Yes, see the fine print on AR's literature attached in earlier post.
  3. ra.ra

    AR2 Tweeter

    Regarding the AR-2x, it was available in at least two variations, with different tweeters, woofers and crossovers. If you use the AR-4x tweeter, your tweeter cap should be replaced with a 20uF. You'd probably need something similar if using the PRT tweeter. But if you use the original AR-4 tweeter (or AR-2ax mid), I think you can simply re-use the original AR-2 oil caps. These AR-4 (2ax) drivers are typically available at reasonable prices. With any of these replacements, the speakers could be used in vertical orientation.
  4. ra.ra

    AR2 Tweeter

    Hi Ken, welcome to the forum. I'm a bit confused by these statements - - - if they already sound lovely, why are you interested in modifying your AR-2's? If you want a historically accurate "upgrade", you might consider the original conversion promoted by AR, which would turn your AR-2's into AR-2x speakers. Replacing with a modern tweeter will most likely require unknown crossover modifications.
  5. One more pic here - - view looking at inside of front panel thru woofer hole. On left is phenolic ring tweeter and at right is the Danish midrange driver with its capacitor, which will be either 20uF or 33uF. Associated sand cast resistors are either attached to driver terminals or globbed onto cabinet panel.
  6. Hi Mark, and welcome to the forum. It's always interesting to hear from someone who has held on to the same pair of speakers for nearly 50 years. Even after more than a year, I have not completed work on the four DA D-4's shown in this thread, but I'll attach a few pics which may be helpful for you. You are correct to not attempt to remove the front grille cloth and underlying grille panel. The only exception might be to facilitate a driver replacement, and I don't even want to think about that procedure. Pertinent access can be accommodated after removing the rear switch panel and the woofer and its screen covering. See pics attached. Even removing the woofer screen/grille is a bit of a challenge. First, you can see from the pic that the frame is constructed from four masonite (actually more like MDF) slats butt-jointed and stapled together, and this prevents the grille frame from remaining stiff and planar as you remove it. These are held in place with many small industrial headless nails, and the only way to remove grille is to be patient using correct tools to slowly and gently pry up the grille around its perimeter. Slightly painstaking, but I was able to remove all four with no damage to the black rear grilles. Removing the switch plate is mostly straightforward, but after removing screws, you can see from pic that there was a material used (latex caulk?) to seal the metal plate to the wood cabinet, and it takes a thin slicing tool to break this seal. On the backside, you will find a jumble of components that make up the bulk of the crossover, but there will also be another capacitor and a couple resistors elsewhere inside the cabinets. I've got some additional pics, but please ask questions as you go along. With one-owner speakers as you have, you may not have some of the problems that I've found - - - in my case, some of the switches and wire terminals have been damaged and will be getting replaced. The very helpful DA expert I've found goes by the name "stickman" on the Audiokarma forum.
  7. I'm sticking with my theory about the sloppy handwritten "H" indicating Holland, but if a plausible explanation for an "M" prefix turns up, it will be news to me. Additionally, I am not familiar with the notion of assembly taking place in Italy, so all of this could be very informative if it can be suitably documented. Your collection is indeed impressive.
  8. It is interesting to see the subtle changes throughout a product's years of production. Not only did the cabinet covering change from wood veneer to vinyl, but I notice a few other minor variations. Your third pair includes a rear-wired tweeter - - it is possible that the part number may have changed with this revision, but I believe it has the same diameter magnet structure as your front-wired versions, and neither tweeter utilized ferro-fluid. Also, I notice that your latest pair has that "Euro" speckled paint on the cabinet backside; and that the terminal panel with switch has been rotated 90°. In fact, I think your latest pair uses a different switch with plastic toggle. Consecutive serial numbers are mostly standard for AR-7's because they were shipped with two speakers in one box. You have a very fine collection. Perfect little kitchen speaker - - often small enough to place on top of upper cabinets.
  9. I am unfamiliar with these stripper products, but it appears your early attempts are rather successful. There still seems to be no consensus about the precise type of wood finish originally used on the KLH Five, but I have read about agonizing attempts to strip these cabinets using other products. Perhaps your thread will open new doors for future restorers of this excellent speaker model. Please keep us informed.
  10. Hi Giorgio, that's a fine-looking quartet of AR-4x's you have. My response here will include a little bit of personal documentation along with some conjecture to try to assist with your mystery serial numbers. The original AR-4 used the letter prefix "F" in the serial number identification. Shortly thereafter, this model was revised to become the AR-4x - - with different woofer, tweeter, and crossover - - and adopted the letter prefix "FX" in the serial number ID. From my own collection, I can confirm these serial numbers for 4x speakers assembled in the USA: 1966: 38,000 1968: 160,000 1970: 320,000 1971: 380,000 I believe you are correct that the extra prefix letter in your serial numbers designates assembly outside the USA, and it is clear that your numbers and dates do not coincide with the USA serial numbers I have listed for general comparison. Clearly, the two European factories (England and Holland) used a numbering system completely removed from the USA production numbers, but I would not know if the two Euro sources shared and combined numbering or if they acted independent of each other. My guess here: in your case, I believe the added prefix letter is not "M"; but instead is a crudely scripted "H" to designate the Amersfoort, Holland location. I suspect that new paper labels had not yet been created to show the European address printed on them - - but as your AR-7 speakers from Holland show in this attached thread, the Holland address was indeed included by 1973.
  11. I think there was more than one woofer used in the Rect-III, and the early ones had pleated paper surrounds, I think.
  12. Thanks for the pics. Did you ever find out from the previous owner what happened to original woofers? I'm just guessing, but it could be another sad case of tossing them once the original foam surrounds failed. Attached are two interesting blurbs from October 1975 Hirsch-Houck Labs review from Stereo Review, as well as a frontal pic with original woofers. It's interesting to note that this is an acoustic suspension design, whereas most of the early Rect models were ported bass reflex designs. The notion of individually factory adjusting each of the pot controls to a fixed setting is mentioned in the review, and you can see the red tips (wax?) of the pots in your pics. Does that 7-inch octagonal Phillips driver have rubber surround?....and whizzer cone? I have a few other Rect 5 documents if interested.
  13. Welcome aboard, 300, and yes, we all like pics. Keep files in the 100KB range with a common file format (jpg) and you should be fine. This is a somewhat rare Rectilinear model, just after they abandoned their typical use of Roman numerals to identify their speaker line. This was during the company's fading days, but they still made a few excellent products (like yours). There was both a Rect-5 and a Rect-5a, and I believe all drivers were different from their earlier flagship speaker model, Rectilinear III (tall boys). Really a shame you are missing the original woofers. If you have pics of the crossover, this might be of interest, too. I'd be curious to see the layout and cap values used for this configuration, but members here also might find it interesting to see that this model used the Aetna-Pollak pots found in so many early AR speakers.
  14. Hi blachool, and welcome to the forum. Welcome to fr3e, too! Aside from the usual woofer re-foam, the most typical component that gets restoration attention in 45 year-old speakers is the crossover capacitor. It may or may not require replacement, but it is a simple and inexpensive process that gives peace of mind for years to come. See attached link. Cleaning the grille cloth can be a delicate operation, but many people have had varying degrees of success using various household cleaners, including upholstery cleaners or spot removers for carpets or simple soap/water solutions. I am fairly certain that your Advent cloth is a synthetic fiber, and you should try to keep the rigid grille frames as dry as possible.
  15. ra.ra

    EPI M-110 Rebuild

    Thx for update on crossover components. I really like having the rotary control in the tweeter circuit, but I think it only showed up in the early issues of their popular speaker models. When you see the x-o replacement that Huw offers for sale, it is nothing more than some decent binding posts, a bit of wiring, and a new (rebranded) cap, all mounted to a small plastic panel.
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