AR2ax refurb crossover questions

[michiganpat]

hey guys, finally getting around to getting my AR2ax's back together from the bare cabinets I bought for $10 3 years ago and have a few questions...

1) the mids I picked up have the wires clipped off at the solder lugs. how do I tell what side is + and what is -? one side has a yellow (to me, I'm color blind) dot next to it. is that the + side? or the side the yellow wire connects to (which looks to be the -side in the schematic I was referencing below)

2) the tweeters I have don't have + or - labelled like some I've seen (these are the 3/4" paper domes). how do I tell?

3) I'm replacing the missing pots with the L-pad/25W resistor combo as outlined in the AR3a restoration guide.

I'm also referencing this jpeg Carl posted over on audiokarma

http://www.audiokarma.org/forums/attachment.php?attachmentid=396145&d=1355622581

in the guide( http://www.classicspeakerpages.net/_Media/restoring-the-ar-3a-2.pdf , pg 15) , the schematic looks like with the L-pad, #1 on Carl's diagram should be #3 on the L-pad, and the yellow shown on Carl's schematic going to #3 looks to actually correspond with the black wire going to #2 shown in the 3a restoration guide? and the black going to #2 on Carl's corresponds to the yellow going to #1 on the restoration guide?

any clarification would help...

thanks!

[Carlspeak]

Pat:

The 3 on my schematic is the same as the "B" on the Aetna-Polak rheostats. I mark a 3 on the center post on the rheostats I sell with my AR kits. I don't recommend comparing the 2ax schematic wire colors with the ones on the AR3a document.

The 6.2 uF cap is marked because at the time I couldn't find any 6.0 uF caps. That problem was solved for me by Erse. I should change the schematic.

[michiganpat]

Carl, thanks for replying....I figured the "3" in your schematic was the same as the B on the original pots

so, looking at pg 10 of the 3a restoration guide, the original wiring of the tweeter section looks to be:

+ to 2 on pot to + of tweet

B/3(on the A-P pots) to - of tweet

- to cap to 1 of pot

and the new wiring (pg 15 of the 3a restoration guide is:

+ to 1 on Lpad to + of tweet

2 of Lpad to - of tweet

- to cap to 3 of lpad

25 ohms bridging 1 & 2

ok, I think I have that straight....looks like I'll have to do some resoldering...that's what I get for trying to figure it out looking at the 2 diagrams at 10:45 last night.....

now, how do I tell + & - on the drivers? with the fiberglass covering the cone of the sealed back midrange, it's hard to do the battery trick to see which direction the cone moves, and I'm nervous about applying DC current to the tweet and noting dome direction movement (if I'd even be able to see it)

edit: I just looked at some pics of 2ax mids on ebay, and my hunch of yellow dot = yellow wire appears consistent on the 3 sets I looked at. so looking at your schematic Carl, the yellow wire should be the - side, correct? or are the mid and tweet wired out of phase with the woofer?

[JKent]

For some reason I can't attach photos (Error The server returned an error during upload)

Will try again later. If you look at the back of the mid, Yellow is on the Left, Green on the Right. You can attach the resistor right there, on the back of the mid.

On the front-wired tweeters, viewed from the front the + is on the left, but the wires cross so the + spring terminal is on the right (if this makes sense).

Kent

[michiganpat]

I had the same issue trying to attach pics....

[JKent]

I had the same issue trying to attach pics....

Maybe this is the reason: http://www.classicspeakerpages.net/IP.Board/index.php?showtopic=7875