Jump to content

KlausDK

Members
  • Posts

    334
  • Joined

  • Last visited

Everything posted by KlausDK

  1. Hi Lars I would as a minimum change the capacitors for tweeters and midrange speakers, not neccessary because I suspect that the old spragues are faulty, but because I think modern film capacitors sound better, i.e. the 6 uF and the 40 uF, and I would replace the 6uF with a 4uF, to comply with your tweeters being 8 Ohm versions. Furthermore, I would, as mentioned above, replace the 10 Ohm resistor for a better type, and bybass the big 2500 uF cap. with a film capacitor of 1-5 uF. BRgds
  2. Hi Lars I have restored a couple of AR-LST's, and on this Danish vintage hifi site, I have a thread on the model and upgrade of the x-over. I guess that you can read Danish https://vintagehifi.dk/forum/viewtopic.php?f=557&t=12513 The models I've worked with, are from the beginning of the models lifetime, X-over looks a little different and it can be accessed from behind. The early models didn't have the 10 Ohm resistor across the big cap, that came later. The big capacitor is important, in order to protect your amplifier, don't try driving the speakers without it. I allways bypass it with a smaller capacitor (1-5 uF) to improva "passage" of the higher fequencies. I would also advice to replace the resistors to MOX versions instead of wire-wound, MOX sounds better in my ears. BRgds Klaus
  3. Have you considered audiofriends.nl based in Holland. I used Fred's surrounds for my AR-9. https://www.repairyourspeakers.com/en/foam-rubber-surrounds/acoustic-research/1-x-foam-surround-for-ar3a-ar9-ar10phi-ar11-ar-lst/a-64-10000023 I used to get surrounds from US from https://www.speakerworks.com/11-Inch-Angled-Speaker-Repair-Kit-p/swk11a.htm I was VERY satisfied with their products, I only changed to reduce customs fees BRgds Klaus
  4. https://www.ebay.com/itm/ACOUSTIC-RESEARCH-AR-11-10PI-ETC-NEW-FOAM-GRILLES-PAIR-2-GRILLES/303690839899?hash=item46b562775b:g:-74AAOSwFQVeNGOf Still some left BRgds Klaus
  5. White glue can come in many "colours", the important thing is, that it retains a bit of flexibility, after it dries up, white glue for wood, for instance, hardens when it dries up, and is not suitable. I use "bookbinderglue", it works fine for me, I have never bought glue from Fred at Audiofriends. I used to buy from Speakerworks, but it got too expensive with TAX, VAT and handlingfee, so I switched to Fred. BRgds Klaus
  6. Hi I don't know of any source for surrounds in UK, I use audiofriends in Holland, excellent service and products: https://www.audiofriends.eu/ Brgds Klaus
  7. According to Tim Holl's paper on "Engeneering the AR9", the acoustic blanket plays an important role in the design and sound quality of the AR-9 speaker: http://www.classicspeakerpages.net/library/acoustic_research/ar-9_series_1978-1981/ar-9_series_other/engineering_the_ar-9_by_tim/ Brgds Klaus
  8. When I see pictures of AR 9 and 90'ies, they almost always are missing the foam inserts around the tweeter and upper MR, that should complete the acoustic blanket around the three drivers in the front. I see even official pictures from AR, where they are missing. Why is that, they obviously was designed with these inserts in place? The last picture is of my 9's, I have made the inserts myself from ½" thick acoustic foam.
  9. Just a friendly reminder, whenever you see those black Callins in you AR speaker, GET THEM OUT!!! 😬 6 uF cap. measures 27.8 uF, poor tweeter!!
  10. The Link to Jensen Capacitors does not work for me either, they seems to have closed the web-site, but their capacitors are still available through dealers, the 2700 uF however, is probably not, since it was a special made capacitor, not intended for audio. You just paralellel the capacitors and the resistor like in this schematic BRgds Klaus
  11. Thanks Roy and Luigi, Luigi, where do you get new voicecoils from? As you can see from the picture, the paperformer in my friends speakers ar completely damagaed/separated. BRgds Klaus
  12. I have a friend, who has blown both woofers in his 10Pi playing some digital music, both coils were pushed out of the magnetic gap, and didn't manage to get back in, so the formers/coils were/are riding on the magnetic pole, with the former completely crushed around the vent holes and deformed. The cone, however, seemes to me OK. Has anybody tried, or do you think it would be possible to dissasemble the woofer, remove the old former/coil from the cone and attach a new former/coil from the above set to the old cone? BRgds Klaus
  13. I have ordered two rings by Larry/ vintage-AR on ebay. Thanks for your help. Brgds Klaus
  14. Thanks Robert, I wish Larry the best of holidays, and will wait patiently for his return ? BRgds Klaus
  15. Just found the answer: "This seller is currently away until Mar 20, 2019, and is not processing orders at this time. You can add this item to your watch list to purchase later." BRgds Klaus
  16. Dear All "Vintage_AR" shop on ebay.com is empty, has he moved to a web-shop outside ebay, or is he temporarily out of business?? I need 2 woofer adaption rings for mounting newer smaller version 10" woofers in an old set of AR.2Ax, didn't Larry use to have those on stock?? Hope that it is not something serious. BRgds Klaus
  17. Thanks Roy, I never had a problem with mine, I replaced the fuses with new, when I got mine 10+ years ago. I use original Bussmann Fusetron FNM2 fuses, hard to get by here in Europe. BTW I apologize for errors in the text in the above post (now corrected, but visible in Roy's quotation , looks like I was drunk when I wrote that (and I was not!!! ); Must have been the autocorrect function on my phone. BRgds Klaus
  18. Very interesting fact that the fuses can cause degradation of the sound. However, bearing in mind how unobtainable/expensive the tweeter are, I would never play mine w/o fuses installed. BRgds Klaus
  19. It is due to the transformator in the LST cross-over, which is not a part of the 3a cross-over. Early versions of the LST did not have the large Capacitor, but they blew a couple of power amplifiers, since the speaker impedans (due to the transformator) went towards 0 with lower frequencies, thus the capacitors were installed; same goes for AR-LST2 and AR 10Pi. both with transformers in the cross-over. Later a 10 Ohm resistor was added i parallel with the capacitor. BRgds Klaus
  20. I love the look of your room, I feel instantly at home surrounded by all those speakers and drivers BRgds Klaus
  21. Really nice work on those 12's Glenn Regarding new fronts, this is also a possibility, and yes, the edge of the foam could have been cut nicer: Foam Grill home made BRgds Klaus
  22. Guidance from AR on maintaining the veneer BRgds Klaus Veneer.pdf
  23. Hi Carl Sorry, I was just being ironical, a Danish folk-art not always easily applicable to other cultures, maybe except the Brittish. I cannot measure ESR, unfortunately. but rest assured, I have no intensions of using the cap for anything else than another addition to the horror cabinet. BRgds Klaus
  24. I am fiddling with a set of unrestored, late version AR-11B (from 1978), and took out the 10 uF tweeter cap for replacement (it is the black Callins? with the red sealing in the ends). Just out of interest, I tested the value on my multi meter, and this must be a record in capacitor off value: 32 uF! I just need an 8 uF in parallel and I can use it for the midrange. BRgds Klaus
×
×
  • Create New...