Jump to content
The Classic Speaker Pages Discussion Forums
David Cutter

AR 2ax Advice Please

Recommended Posts

51 minutes ago, David Cutter said:

Update:

I see now that previous owner cut pot wires to connector 1 and B. The inside contacts are pretty bad and I have tried a few different techniques to clean them up.

Deoxit, Dremel buffer, fine sandpaper, metal polish, elbow grease....

The brown oxidation is difficult to get off. Any ideas? 

See pics.

I have one...the trash bin.

Corrosion and attempted cleaning have taken a severe toll. I also noticed a hole in the wiper tip in the photo, and it appears the resistor wire has been sanded or "Dremeled", which can change the resistance properties of the control. There is no value in retaining pots in this condition when reliable alternatives are available.

Roy

Share this post


Link to post
Share on other sites
41 minutes ago, RoyC said:

I have one...the trash bin.

Corrosion and attempted cleaning have taken a severe toll. I also noticed a hole in the wiper tip in the photo, and it appears the resistor wire has been sanded or "Dremeled", which can change the resistance properties of the control. There is no value in retaining pots in this condition when reliable alternatives are available.

Roy

Yes, I agree. I ordered some L-Pads from PE. Thanks.

I enhanced a pic I took of the woofer manufacture date stamp. Looks like Nov 15 1965 or 1967 to me. Last number is very faint. Any opinions?

 

date-stamp.jpg

Share this post


Link to post
Share on other sites
18 minutes ago, David Cutter said:

I ordered some L-Pads from PE.

This has been printed before but FYI here are Roy's L-pad instructions and pic:

Quote

When using an l-pad, it is important to make sure the original polarity is observed. Below are photos showing the original AR-3a midrange pot and a replacement l-pad with the appropriate connections. The original pot terminals and the replacement l-pad terminals are labeled differently (1, B, 2 for the pot and 3,2,1 for the l-pad). I have indicated the corresponding pot tabs on the l-pad. 

 

pot_and_l_pad.JPG

Share this post


Link to post
Share on other sites
22 hours ago, David Cutter said:

One interesting thing...The serial numbers are close together in the 22000 range, but the finishes don't match very well when they are side by side. One is noticeably darker.

I know that in 1969 speakers were not always sold as matched pairs, and that stereophonic sound was not widespread yet. So often people just bought one for their current mono system, and bought a second one later when they upgraded to stereo.

David,

The difference in finish on your speakers may simply be due to their placement through the years. One speaker may have had more exposure to sunlight than the other, which can certainly lighten the wood. With both speakers having close serial numbers in the 22000 range, they likely were purchased together.

21 hours ago, Steve F said:

This is incorrect. Stereo was introduced in 1958 and was an immediate success. Part of the reason that AR had such market dominance in the mid-60's (over a 30% market share in 1965) is that with AR speakers, a listener could easily fit two compact speakers into a living room and enjoy deeper, better bass than from a single older-design bass-reflex speaker.

By 1969, there were virtually no mono systems at all. Everything was 2-channel/2-speaker stereo.

Steve,

I did come across an interesting outlier to this a couple of years ago.

I won a pair of AR-5's at a local real estate / contents auction. Both were in unfinished pine cabinets and one had been painted white. interestingly, the serials were far apart. One speaker was stamped with a K10892, the other had a handwritten K26010. The woofer dates were clear: Oct 1969 and March 1972. Likely the original owner had purchased one to use in a mono setup until they could upgrade, at which time they ordered another unfinished pine unit. Luckily for me, the owner opted not to paint the 2nd speaker.

The owners final upgrade was to a pair of Klipschorns, also in unfinished (stained) cabinets. The person who won them brought in a handtruck to remove them. According to the carpet underneath, and the surrounding wall paint, the speakers hadn't been moved in forty years.

Share this post


Link to post
Share on other sites
On 5/10/2019 at 8:27 AM, Aadams said:

I am not sure exactly how those woofers fasten but I doubt the threads are stripped.  Both topic and remedy have been discussed on this forum.  When you get the woofers out supply a photo of the problem holes and someone who knows will comment.  

EDIT:  This link discusses your problem.   You have plywood baffles not particle board.  You may just have a loose fastener on the backside of the baffle.

I opened up one speaker and found the T-nut in the fiberglass. Looks like I can just glue it back in. Thanks.

 

 

Share this post


Link to post
Share on other sites

UPDATE:

Ordered all of the necessary parts and using the standard schematics provided here, I updated the crossover. Before I close it up, here is a pic of what it looks like. I haven't tested it yet, so I have no idea if I did it correctly. 

Update: Connected speaker...Tweeter not working :-(. Will open her up tomorrow and see what's up. xover1.thumb.jpg.346d220128ce79d08e2c2b0b1dc22fe5.jpg

 

xover2.jpg

xover1.jpg

Share this post


Link to post
Share on other sites

If you don't already have the answer, you might want to find out if a resistor is recommended on the "orange" tweeter lpad.  RoyC will know.   It won't be fatal if you don't use one.

Adams

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×