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johnfalc

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About johnfalc

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  • Birthday 03/25/1946

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    Male
  • Location
    El Cerrito, California USA
  • Interests
    Music, Audio, Vintage motorcycles, Photography, Computing technology

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  1. Yes ... those 6uF seem to be particularly awful. You'll see in the attached image that one of the ones I removed from my AR-9's measured 77uF at 1KHz - 1,180 percent of its nominal value! The other one was only 31uF, 416% of nominal. Getting the correct values in the crossovers certainly makes a significant and audible difference!
  2. Yes, 9's in the VB room were always my favorites then too. I now have 9's and 90's. What region of PS were you in?
  3. Quite interesting that both your and my 4 and 8uF caps were very close and that it was the 6uF in both our cases that were so far from nominal. Looks like anyone with AR-9s or AR-90s (maybe others) should take the time to, at least, check those. Of course, your and my measurements suggest that anyone who wants something close to the original sound should get in there and do a replacement of all those caps involved in the upper drivers. I'm quite happy with the Erse caps and am still running my 9's and 90's with the switches set to maximum output to the drivers. I may take some measurements
  4. Yes, they are the red Callins caps. I measured the first one multiple times ... then was amazed when the second one was even further from nominal. I agree there must have been a serial defect ... I wonder how many are still out there in 9's. And yes, thanks to the 4uF and associated inductor, the tweeters are fine.
  5. I finally got around to changing out most of the capacitors in the AR-9s I picked up about a year ago. I had always felt, that in spite of their fabulous bass, the mid and upper ranges suffered by comparison to my AR-90s (which I had recapped seven years ago when I got them). Anyway, for anyone who's on the fence about doing this job ... please take a look at the values I measured for the old caps - quite illuminating, especially the measurements for the 6 uF caps. The sound is now just as it should be, to my ears. Imaging, especially of solo instruments and voices is now rock steady a
  6. That's a nice diagram and it matches the factory wiring diagram and my photos. I understand the layout just fine. My post is just drawing attention to the fact that the schematic in our library doesn't match this diagram, the factory diagram, or my photos, that's all. Note that the LMR green white is connected to BOTH capacitors which is not how it appears in the schematic.
  7. No. The difference I'm noting is ONLY in the order of components in the LMR circuit. What I'm drawing attention to is that the schematic and wiring diagram show different orders for the inductor and 80uF cap. It doesn't matter electrically but I like agreement on such matters. John
  8. Note I attached the AR-9 schematic but the AR-90 is the same for the LMR/HMR/TWT.
  9. About seven years ago I replaced the caps of my AR-90s and I'm about to do the same for a pair of AR-9s I bought last year. In reviewing the schematics and wiring diagrams I found here, along with photos I took at the time of the AR-90's crossovers prior to working on them, I find an inconsistency. In the schematic diagram the lower midrange units are driven through the attenuator, then through an 80uF cap followed by a 2.63MH inductor with a 30uF cap in parallel with the driver. Note that in this depiction, no direct connection exists between the two capacitors. However, in t
  10. AR-2ax are a great choice for this in a smaller room. I run them on a very similar Fisher 800C. You would want much more power in a larger room; I run one or two Carver M-1.5t in my living room with AR-9 or AR-3a.
  11. I don't see this document in the AR section so I'm posting it here so that an admin can load it, or let me know we already have it. This is from when we were a very large seller and repair operation for AR. I don't have any original AR-3 personally but this may be of use to others. JohnAR_Service_AR3_MR_Replacement.pdf
  12. I'm guessing that the two caps discussed (blue and silver) are the same capacity and, although physically in different locations, in the same position circuit-wise ... different vendors but equivalent function. Trace the wires, do they connect to the same places? Forget that - in looking on a higher resolution screen I see that both have their large aluminum cans in place ... the first one I did not see on my phone.
  13. My understanding from reading (mainly here) is that the original, early AR-2AX speakers used the same 4 ohm orange dome tweeters as the AR-3 and that the later AR-2AX speakers use an 8 ohm version of the 3/4" black hard dome tweeters which were used in the AR-3a (but the 3a version of these tweeters are 4 ohm). If this interpretation is correct ... My question relates to the (if any) changes made to the crossover network, i.e., was the size of the series cap feeding the tweeters changes at the same time and, if so, from what to what? Thanks, John
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