Jump to content
The Classic Speaker Pages Discussion Forums

ra.ra

Members
  • Content Count

    2,005
  • Joined

  • Last visited

Community Reputation

0 Neutral

3 Followers

About ra.ra

  • Rank
    Advanced Member

Profile Information

  • Gender
    Not Telling
  • Location
    metro Boston

Recent Profile Visitors

8,912 profile views
  1. ra.ra

    12.5 question

    Hi ChrisM, if you have observed some subtle difference in the cloth surrounds from various drivers, the very best way to receive specific feedback to your questions would be to post a few well-focused good quality pics (± 100KB is fine) for readers to see the situation you are trying to describe. This is very easy to do, and it is always helpful.
  2. If you post some pics of your crossovers, members might be able to give more specific advice about the potential re-cap ideas. Generally, I agree with others that these would most likely benefit from full cap replacement. Kent raises a very good point here which should be researched and confirmed. While I find it difficult to think that a serious 70's receiver could not be adequate for a single pair of 4-ohm speakers, the Marantz literature is indeed very non-specific on this topic. The user's manual makes only this one mention of 4-ohm speakers, and even this statement can be read with two interpretations.
  3. Without looking this up to confirm, I believe the primary difference between the AR-7x and the AR-7 is that the 7x uses a tweeter with ferrofluid for somewhat increased power handling. Also, I think the 7x was offered only in Europe, uses a multi-color cabinet stuffing, and often had the lovely teak veneer found on many Euro cabinets. The 6uF cap (and switch and resistor) found in the AR-7 is dedicated to the tweeter circuit only, and the woofer has no crossover components - - I'm pretty sure the 7x circuitry is essentially identical. Regarding the bass performance, I think you'll need to closely inspect the problematic woofer. Be certain that the cone seems to have adequate movement potential, but also, I can imagine bass performance suffering in a small sealed cabinet if the woofer foam has developed any cracks or deterioration.
  4. Aadams, Glenn is much more active on the AK site than he is here, so I'm just helping out by providing a link to his other thread for others to read-listen about the recent gathering - - - a whole lot of very nice gear and music. https://audiokarma.org/forums/index.php?threads/peekskill-ny-blue-mountain-lodge-audio-fest-saturday-september-14th-2019.851987/page-9
  5. ra.ra

    KLH Model Nine in NJ

    Not sure where you are located, but there was a pair of these being demo'd today at Glen's get-together. http://www.classicspeakerpages.net/IP.Board/index.php?/topic/10476-peekskill-ny-blue-mountain-lodge-audio-fest-saturday-may-18th-september-14th-2019851987/&tab=comments#comment-126463
  6. ra.ra

    12.5 question

    You should be able to find this in quart container - - - not sure about your state, but it's legal here and available in many good hardware stores.
  7. ra.ra

    12.5 question

    Yeah, you may be right, Pete, but that data sheet does not describe the chemistry of the solid components, so we just don't know. Always a good idea, particularly in a "test case" scenario. I have some AR-4 woofers that had never been touched in fifty years but the surrounds were dry, and a little bit stiff and delicate. Carefully, I brushed on some solvent a few times and let that fully evaporate, then followed up with a light coat of Roy's butyl and this really did improve their texture and flexibility.
  8. ra.ra

    12.5 question

    There have been many hypotheses applying and guessing at suitable re-sealing materials which have resulted in damaged or ruined drivers, and unless/until these materials are documented with results measured over time, my own attempts to re-seal cloth surrounds will remain confidently loyal to the liquid butyl goop that Roy has cooked up and generously shared with this community. It works very well on AR and KLH drivers, and I see no reason why it shouldn't perform the same on these Phillips drivers or similar. BTW, where does this "12.5" nomenclature come from?
  9. Yes, this is correct. There is a similar marking on the backside of the woofer baskets for the identical purpose.
  10. ra.ra

    12.5 question

    Both the KLH 12.5 and the Phillips 5060 are open-backed with cloth surrounds. In the KLH Five and Twelve (used in pairs), they are installed in their own separate sealed cabinet chamber. My familiarity with the Phillips driver (with whizzer cone) is from its use in several of the best Rectilinear speaker models, where it is installed in an isolated cup chamber. Attached images are: KLH 12.5; Phillips 5060; Phillips 5061; and 5061 tech sheet. If you look closely at the Phillips cones, there appears to be traces of a liquid sealer probably used on the cloth surrounds.
  11. I plucked these pics from stever's attachment so that other readers won't have to open up a 21MB document. I agree with Kent - - no need to switch binding posts - - those look perfectly fine to me. These speakers do appear to be in very nice condition. However, the rust on the driver screws suggests that these may have been stored in a humid environment, and it would be worth taking a look inside at all components for any further signs of corrosion.
  12. Hi, Marc, and welcome aboard. With your collection, you know more about BA products than I do, but it appears to me that everything shown is most likely original - - am curious, what makes you think otherwise? Quite possibly, what you heard moving was the black 16uF Bennic cap, which has become dislodged from its original position with hot glue adhesive. Edit: Oh, now I see - - - it appears that the upper left coil and resistor have also become dislodged - - it should be very simple to re-attach everything in original positions with a few dabs of hot glue.
  13. Hi stever, I think what Larry means is that there are many threads on this site about the AR-91 that will tell you everything you need to know. Some people regard the 91 as among the very best three-way speaker models ever conceived by AR, so you should read up a bit before you do anything. For an intro to this topic, just copy the line below and plug it into your favorite web browser for a number of excellent online threads. site:classicspeakerpages.net "AR-91"
  14. Off topic, but......I just re-read that thread of your AR-91 restoration, and I see in an edited comment that you have soured on Erse caps - - what happened here?
  15. ra.ra

    AR-9

    Most likely, the backside of the drivers will have an ID sticker label, and these should have info that satisfies this question of roughly dating the speakers.
×
×
  • Create New...