DavidR

When polarity is different the drivers move in and out opposite to each other. Sound would arrive at a slightly delayed time for those drivers not in phase. Perhaps the smaller woofers of the 90 were 'drowned out' with all drivers in-phase. By having the upper 3 drivers delivering sound with that slight delay the bass would appear stronger; and remember the longer waves move slower. Just a guess as to why.

The crossover schematic(s) matches what is in my (early; s/n around 1500) AR90s. I do not believe this is a mistake. For example, on the tweeter, the blue wire (neg) goes to the series capacitors (the 4 and 6); the yellow wire (positive) goes to ground/negative - exactly as shown. I bought them from VintageAR. I have Ken Kantor's email addy, perhaps I will see if he has any knowledge on this. He was a young engineer at AR at the time. I took a pair of cheap Yamaha speakers and only re-used the woofer. It had a single cap but was a three way design. I modded it and bought a better mid and tweeter and made a 'crude' wiring crossover. I wired all in-phase. It didn't sound right. Don't know what made me try this but I ended up wiring the tweeter out-of-phase. It then sound 'right' and has stayed this way.

It is obviously by design. That is how the AR engineers made the crossover. You'd have to ask the AR engineers about changing the phase and its effect on SQ. "Common fix" > not a 'fix' if you change what they did. If you want to wire it like an AR9 then reverse the wires on the tweeter, UMR and LMR. But why do it? They did it for a reason.

On the AR90 the tweeter/UMR and LMR are wired out-of-phase and the woofers are wired in-phase unlike the AR9 where all drivers are wired in-phase. You will notice in the wiring schematic all the plus (+) side of those drivers go to the negative (-) speaker binding post (but not the woofers). My recap also improved SQ and really brought out the LMR. Many of my caps measured within the 10% variance BUT were acting as a resistor. My upper mid and tweeter were totally muted. IMO, there is no need to use the more expensive film caps. Today's non-polar (NPE) are much better than the originals and the speakers 'behave' as intended and sound more authentic. I did, however, add a small film bypass (0.01uf) capacitor in parallel to all series caps.

You can get help with the Dynaco gear at this website> https://dynacotubeaudio.forumotion.com/ Is the unit with the cage a tube amp? You inherited some nice gear !

Nice find

I doubt they are the same. The AR2a is an 8ohm speaker and the AR3 is 4ohm. Perhaps someone with more knowledge of those models will know for sure.

Try opening or downloading this pdf restoring_the_ar-3a_full_pd.pdf

That's it and is all that is needed. Good work.

I've done what Aadams suggested and with great success.

I think you might be thinking of NHT (Now Hear This) by former AR engineer Ken Kantor.

Hi Frank. Hope you are well and enjoying your ARs. I'm determined to get a pair of true AR speakers (before Teledyne). I'm running out of room and moving right now is not on the agenda. I would love LSTs or AR3a or AR5. The LSTs might be a struggle with available space. Depends on how bad the itch gets. Be well.

Just a little more than an hour north of me.

If they are original then YES

You could also use Liquid Nails. Both should be available at a Home Depot. Merry Christmas to you, as well.

I'd try and remove the old glue. Titebond should work. Comes in a caulking tube. http://www.titebond.com/

Not sure what side panels you are referring to. Could you post a picture?

Nice repair work Giovanni

Translation: Repair voice coil holder slightly squashed on bottom edge, but enough to rub in air gap and re-foam.

The A2 is a well received amp. I think you'll be happy. I have an A100 Headphone amp and run speakers with it (50wpc 8ohm/80wpc 4ohm). Clarity and stereo separation is stunning.

You have a 30 day return window. I've owned 2 Emo amps. First the XPA2 Gen2 which I sold and got an SA250 which I liked so much I got a second one.

My AR9 Owner's manual has the impedance dip to 3.2 ohms. I have no clue about your Quad 606. Sorry. I used to have a CT-7. Nice, attractive Pre. Doesn't the CT-7 have 2 Pre Outs? or am I thinking of my C-1 ?

Don't invite an Addams over ...............

Must be 3 union workers