Interesting AR info

[xmas111]

A friend sent this to me. Thought is was a very interesting read.

On the right hand side there's more links about AR equipment.

I found the picture of the very early AR3 quite interesting, never seen one like that before.

If it's been posted before I apologize, I've never seen it before.

http://retrozound.bl...of-passion.html

Enjoy,

John

retrozound.blogspot.com200907history-of-passion.html

[Rob dalton]

Thanks for the link. The article really gives a sense of history to ARs and particularly to AR3s. I have a pair of AR3as and had never paid much attention to their S/Ns. They were purchased at different times as I had the money, and one is in need of work as the woofer is not working right, and mid-range is out. The other AR3a is working perfectly. Here's the amazing part, the working AR3a is S/N 00097. Wow! Is this amazing to anyone else?

Rob

[dynaco_dan]

Hi there

#97 is really an early unit.

Likely made on the very first day of production.

I also needed to buy one AR-3A at a time to keep the peace, so to speak.

[Rob dalton]

I'm using my Dynaco 70 and Pas 3x pre-amp to drive my AR 3a (noticed you were dynaco_dan). I built mine from kits, and probably should sell them but they're still working great and I'm too nostalgic. I'm getting good at replacing bass surrounds, but I think I have voice coil damage on one of my Ar 3A woofers (haven't tackled any voice coil problems), it moves and puts out sound but at even modest volume I hear a buzzing sound along with the bass. Anyway. I like to think my 00097 is working so well (original surround) because Villchur himself supervised its construction.

[dynaco_dan]

Hi there

Both the Dyna ST-70 and PAS-3X are highly sought after equipment today.

More efficient speakers sometimes work better with tube amps.

As a mint pair they may go for upwards of $1,000.00, or more, a little bit more than the kits cost you.

Not the best choice of amps for AR-3/3A speakers unless used only at lower listening levels.

Both these are 4 ohms and cause a lot of amps to work over their capabilities all the time.

Try inverting your speaker cabinet to see if after a while the buzz may subside, it's worth a try.

If so the spider is likely sagging slightly.

Other advice will be coming along as members read this topic.

Until then do not do anything to the woofer.

Dynaco_Dan had a nice ring to it when I needed a user name, my name isn't even Dan.

Possibly both Henry and Edgar may have touched your speaker cabinet by chance at the factory, we'll never know.

[Rob dalton]

I discovered why I have the buzz in one of my AR 3as. I replaced the bad foam surround with cloth surround, a technique that has been documented on the internet. Thinking that the bass speaker has to be free to move, I allowed extra cloth so I could form a curl much like the original foam has. With cloth this allows the speaker lots of movement (probably too much). Anyway when feeding a 32 HZ sine wave, I can eliminate the buzz and get a pure sounding bass by tugging the surround towards the outside in an area about 25 degrees wide. since the cloth is glued to the frame and to the speaker cone, I have to figure out how to make this slight outward pull permanent without trying to get the cloth off the frame. Believe it or not, since the surround is cloth, I have thought of using a safety pin to shorten the surround fabric and create the tug. With 32 HZ in it's easy to check the sensitivity of the cone (probably the voice coil) to buzz, by gently tugging on the surround as you move around the cone. It seems centered every where else except this 25 deg area. Glad I had my little B&K tone generator, because it really tests the sensitivity of the cone to buzz. Finally, I don't have enough experience to know if this Ar 3a had a voice coil issue, or whether allowing extra cloth surround caused the problem. In other words I don't know how much support the surround is supposed to give the cone and the voice coil.

As others have pointed out you want to be gentle while feeding a sine wave to a speaker, because you can easily generate more bass energy than you will ever see in music. Feeding a sine wave is an interesting test when done gently. You can determine the point at which the speaker doubles the bass and distorts by producing twice the input frequency. Up till this point with a good speaker you feel the bass at 32HZ as much as hearing it. If the speaker cranks out a high volume before doubling, it's a good one. The bad thing about the test is every speaker will double (distort) at some point so unless you have maybe a Klipsch horn enclosure, you can forget about extremely loud undistorted bass.

[ironlake]

you can r eplace the cloth with foam

[RoyC]

I discovered why I have the buzz in one of my AR 3as. I replaced the bad foam surround with cloth surround, a technique that has been documented on the internet.

Rob,

Where on the internet is this documented?

The surround is an important part of the suspension system, so the cloth surround you fabricated could very well be the source of the problem. It may be too compliant, and/or the voice coil is rubbing.

Roy

[tysontom]

A friend sent this to me. Thought is was a very interesting read.

On the right hand side there's more links about AR equipment.

I found the picture of the very early AR3 quite interesting, never seen one like that before.

If it's been posted before I apologize, I've never seen it before.

http://retrozound.bl...of-passion.html

Enjoy,

John

This is a nice historical perspective; however, it uses several of my AR and Ed Villchur images without permission, and the facts in the article are fuzzy and incorrect in places. I think it great to have different historical references, but on the internet there is a tendancy to just "lift" material and ad-lib where necessary, thus providing in some cases incorrect and misleading information.

--Tom Tyson