AR3a Tweeter repair or replace?

[RoyC]

The AR-3A are tops on my list of "Why did I get rid of those?"
There is a great article on the Classic Speaker Pages web site regarding the AR-3A. It has info on restoration, and also a time line with pics for the different drivers. There was quite a few changes in the models over the years. Some big, some small. IMHO, they all made some difference. I prefer to restore to original myself.
Here is the link: http://www.classicspeakerpages.net/...ginal_models_schematicss/restoring_the_ar-3a/
Good luck with your renovation.
G

I am one of the authors of the CSP AR-3a restoration document. Feel free to PM me with any questions.

Roy

 

[glenwcar]

I am one of the authors of the CSP AR-3a restoration document. Feel free to PM me with any questions.

Roy

A quick and momentary thread hijack.
Roy
It is not often enough that we get to give thanks where it is due. The AR-3A restoration piece is the definitive reference in my friends" houses as well as mine. A great work, take a bow. Thanks. Glen

And now back to the thread.....

 

[RoyC]

A quick and momentary thread hijack.
Roy
It is not often enough that we get to give thanks where it is due. The AR-3A restoration piece is the definitive reference in my friends" houses as well as mine. A great work, take a bow. Thanks. Glen

And now back to the thread.....

Thanks, glenwcar. We very much enjoyed sharing our collective experience. There has been talk of an update to include the HiVi tweeter, and a few other things.

Since the document was completed it has become increasingly apparent that the 3/4" dome tweeter used in the AR-3a (4 ohm) and the AR-2ax/5 (8 ohm) is physically deteriorating. Larry Lagace ("Vintage AR") and I recently tested a number of these old timers, and found them to be very inconsistent. Dissections of dead specimens always show crumbling foam under the domes, and compromised suspensions.

Roy

 

[HepcatWilly]

Lo-d Dad, if you are a member of AK, you can post in BarterTown for a replacement, but I see that Gordon has already sent you a PM.

As Gordon illustrates, the great thing about AK is that someone here has the part you need in their basement and are good enough to share with a fellow enthusiast.

If you do go with Larry (VintageAR) for that woofer, I can tell you that he is a super guy to deal with. I've dealt with him a good few times, and he's given me advice that saved me a lot of money that he could have easily pocketed if he wanted.

RoyC, I have to join Glenwcar in thanking you for the information, it was invaluable in helping me restore a pair of AR LST2s.

 

[Ed in Tx]

Since the document was completed it has become increasingly apparent that the 3/4" dome tweeter used in the AR-3a (4 ohm) and the AR-2ax/5 (8 ohm) is physically deteriorating...

Hi I have a pair of the later version 3a's made in the mid-late '70s. Does the deteriorating tweeter problem apply to those too?

 

[RoyC]

Hi I have a pair of the later version 3a's made in the mid-late '70s. Does the deteriorating tweeter problem apply to those too?

Unfortunately, yes...The 3 orange blobs around the dome comprise a urethane foam suspension. It is the same stuff used for damping purposes under the dome. A butyl rubber compound, which was applied over those foam suspension blobs, seems to have held them together better than the foam under the dome, but performance appears to be increasingly variable. An interesting aside is that the quality control of the later, back-wired version of this tweeter was not as good as the earlier front-wired version, serving to complicate matters even more. Near the end of its run the urethane was coated with grease instead of the butyl rubber compound. This stuff is notorious for getting into the voice coil gap, and literally gumming up the works.

In light of the above, Vintage AR/Larry L. recently told me he is no longer seeking used 3/4" AR-3a/2ax/5 tweeters to complete restorations. At present, he is replacing missing or malfunctioning tweeters with pairs of HiVi Q1R drivers, as mentioned earlier in this thread. (BTW, the subsequent ferro fluid cooled 3/4" AR-11/10pi. tweeter was more conventionally constructed, and a step forward in reliability and consistency. This tweeter, with a small parallel inductor, can also be used as a drop-in replacement for the 3a tweeter. They are difficult to come by, however.)

If your AR-3a's sound OK, I would just continue to enjoy them. There are still original tweeters providing acceptable performance out there...just not as many as there used to be.

Roy

 

[lo-d dad]

Lo-d Dad, if you are a member of AK, you can post in BarterTown for a replacement, but I see that Gordon has already sent you a PM.

As Gordon illustrates, the great thing about AK is that someone here has the part you need in their basement and are good enough to share with a fellow enthusiast.

If you do go with Larry (VintageAR) for that woofer, I can tell you that he is a super guy to deal with. I've dealt with him a good few times, and he's given me advice that saved me a lot of money that he could have easily pocketed if he wanted.

RoyC, I have to join Glenwcar in thanking you for the information, it was invaluable in helping me restore a pair of AR LST2s.

That is great to know. This site has already been very helpful and informative to me. Thanks again.

Lo-d dad

 

[Ed in Tx]

Unfortunately, yes...The 3 orange blobs around the dome comprise a urethane foam suspension. It is the same stuff used for damping purposes under the dome....

Roy

Wow. Thanks for the information and picture of what goes on under the dome.

 

[lo-d dad]

GordonW,

I sent PM regarding your tweeter.

Thanks,


Lo-d dad

 

[harry398]

Larry is selling the ABT tweeter as an AR-9 replacement tweeter, and the HiVi tweeter for the 3a, 2ax, and 5.

I personally do not like the ABT tweeter as a 3a replacement (too harsh), even with the parallel inductor. The HiVi Q1R sounds more appropriate to my ear (using the same inductor), at a bargain price. Parts Express is now recommending the Q1R for this purpose as well.
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=297-417.

Roy

I also have to agree with Roy. I really enjoy the hivi qr1 in a set of ar3a's. I have a .05 inductor on it, and left the stock value on the Cap. just great.

so....has anyone run a Hivi on a ar11? any other changes?

 

[GD70]

Larry is selling the ABT tweeter as an AR-9 replacement tweeter, and the HiVi tweeter for the 3a, 2ax, and 5.

I personally do not like the ABT tweeter as a 3a replacement (too harsh), even with the parallel inductor. The HiVi Q1R sounds more appropriate to my ear (using the same inductor), at a bargain price. Parts Express is now recommending the Q1R for this purpose as well.
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=297-417.

Roy

I'll add to this Roy also recommended the Q1R for my LST-2's, with the inductor mod and cap swap in the crossover.