johnfalc

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.

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

Note I attached the AR-9 schematic but the AR-90 is the same for the LMR/HMR/TWT.

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 the wiring diagram and in the photos I took before working on the AR-90 crossovers, the order of connections is different. This diagram (and the reality of what I found) show the lower midrange units driven through the attenuator, then through the 2.63MH inductor followed by the 80uF cap to the driver which, again, is paralleled by the 30uF cap. Note (for it makes it easy to see the discrepancy) that in this case the two capacitors are directly connected in series with the driver driven from their junction. Simulating the circuit demonstrates that the frequency and phase response are the same either way ... it just seems we should correct the schematic to match the wiring diagram and what I found in the AR-90s to eliminate any confusion. When I get to doing the AR-9s I'll take photos to see if this is a consistent discrepancy.

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.

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

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.

Thanks Roy. John

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

Thanks Roy, Since I don't know the provenance beyond the recently deceased that sounds possible. I'm told the replacement parts were ones that the prior owner had installed by some authorized center/dealer, having bought them new. Agree about the tweeters but I'm going to see what they do first, out of curiosity ... all the work that's been done has been done in a workmanlike manner; good to see.

I agree ... definitely not "rough!" I'll enjoy bringing them back to excellent - but I'm pretty much out of rooms for systems - already have 2 pair of 3As, and one each pair of 9s, 90s, 92s and was recently passed a pair of ADS L880s by a deceased friend. I have a spare Fisher 800 (same as the 500C but with AM in addition to FM) and the AR-2AX might be a fun vintage combination with that. Yes ... I also got the amp - it is the small "Grandson" amp with meters. I'm told it is dead on one channel but that's no obstacle since I keep a full bench here at home (somewhat nostalgic about back when I worked in the industry). The amp is a nice, symmetrical design and should be easy to troubleshoot. I guess it could live in my workshop ... I already have four Carver M-1.5t amps that I use plus keep as spares (I buy them broken and fix them up). Still curious about those tweeters ...

A friend for whom I have done amplifier repair in the past was recently given what he told me were a "pair of AR-2a speakers in rough shape." He asked if I wanted them and, given that I'm trying to reduce rather than add to my assorted hi-fi gear, I declined. He then told me he was going to take them, and a GAS amplifier, to land fill and I said "Whoa ... bring them here and, if I don't want them perhaps someone else will ... don't trash them." Today he dropped them off and: They are AR-2ax, not AR-2a. They need surrounds for the Service Replacement 200004-2 woofers (which I've ordered from Vintage AR) They have tweeters that I haven't seen before. They are labeled as Service Replacement 200013-2 tweeters (correct for this model) ... however: They have the correct hard, small, dome which, by appearance is the same as the dome fitted to the AR-3a They do NOT have the three small orange foam dots - that suggests they've been repaired at some point They measure 7.0 ohms DC They have self-adhesive foam applied to the fronts - someone's attempt at minimizing speaker baffle edge effects, I'm guessing The cabinets are in great shape - a bit of a planter-ring water mark atop one of them but the other surfaces are remarkably attractive. Anyway, I think I'll go ahead and restore these - too many good parts and great cabinets to be tossed. Three questions for the group: Have you seen tweeters like these before? What DC resistance should the voice coils of the tweeters be - I think 7.0-7.1 is what I've seen in the other AR-2ax I had, but I gave those away last year. Any conjecture on build date given the serial number 166472 (the other is similar). My guess is fairly late ... like 1972-1974 or so. Some pictures attached.

Depends on the room I'm in ;-). One pair of AR-3a flank our large-screen TV so they are often in play. The AR-9 are on a different wall of the living room so they get listened to for "serious" listening and when we want to dance. The AR-90 are in the bedroom ... All are powered by Carver M-1.5t amplifiers.

Thanks for doing the legwork on this. The only thing I have to offer from my own experience is that the 200027 and 200045, while they seem almost identical in many regards, use different cone materials and, at least to me (and others who commented here in earlier posts) sound different enough that it makes sense (if you have AR-9s or AR-90s - I have both) to use only the originally-intended 200027. My "discovery" of this occurred because a pair of AR-9s I purchased last year had the 200045 LMRs and didn't sound "right" until I replaced those with the 200027. Another column showing cone material (and perhaps even details specific to surround attachment) would be a nice addition to your work.

Glad to see you're back!