DavidR

I believe it was RoyC who broached this subject and tried an 032 in an AR9 and could hear no difference.

You're in luck! Animal37 just posted a pair on eBay. Item # 334304399850

@tenofossil Its my understanding that the 032 can be used to replace a 028 but not the other way around.

You can sometimes find them on eBay or the 200032 which will work. I tried one of these and found it to be a very good replacement. https://www.midwestspeakerrepair.com/shop/home-audio/midranges/others/mw-audio-mm-2044-acoustic-research-copy-midrange/

I keep my eyes open for a pair of 3, 3a and 5 in C.L. and yard sales.

Welcome to CSP. Nice speakers designed by Ken Kantor. I had a chance to pick up a pair thru Craig's List but have too many speakers and would rather try a pre-Teledyne pair next.

Some times I think Ken's contribution to the audio world are overlooked. I remember when I used to frequent AudioKarma site --- many people didn't treat him too well. Perhaps they had no idea who he was.

I did a Tempest Search for the unit in all the USA and Canada. Sorry, but nothing came up.

Welcome to CSP. Those are some fine speakers. Please see the PM I sent to you. PM = Private message

A short ride away from me. Hmmmm, do I need another pair of speakers?

Tube testers have many pot switches they tend to have layers and some are plastic that is not compatible with deoxit. I don't know what's inside your volume control knob so I was alerting you to a possibility and to use caution. That's all.

I'd go with the brass as some stainless steels are somewhat magnetic in the Martensitic family and, obviously, the Ferritic family of stainless steels. Austenitic stainless steels should all be good (and most pricey).

The pots may be able to be flushed out with DE-oxit D5 spray. It is safe with most electrical components BUT I do know the old Sencore tube testers have trouble with a thin plastic material spacers in the switch components.

Because of your post on Victor's passing I found out he lived right down the street from me - just a few houses down. I knew Lillian as she walked her dog by our house (she recently moved). Had I only known. He had a nice pair of Allison 9s. Do you know if Victor worked for Roy Allison? His business was in the next town over.

Nice article. Wasn't it C. Victor Campos who has originally wanted/suggested the AR9 to be powered speakers (internal amplification) ?

Not a good idea to switch butyl for foam or the other way around. Some say a surround has a 'break-in' period. Foam surrounds are considered more compliant; however, each driver is designed for one or the other.

Lately, all of the attachments and info in the Library are flagged by McAfee Antivirus as potential risks. What's up with that?

PM sent

50VDC equals approx 35VAC. All of the AR speakers I've worked on are listed in AC, but all are Teledyne/AR era. However, I have not worked on any of the older models like an AR5. It does matter as speakers run on AC current. DC is blocked by a capacitor.

50 volts AC

I believe it was Steve Hoffman who tested several types of resistors on a scope. If you don't mind noise and distortion introduced into your music then cheaply made resistors work just fine.

Resistors may not go bad unless you overload them but there are affordable resistors that are WAY better sounding; like the Mills. The Mills are also 1% tolerance and usually are closer than the 1%.

If you're going to change those old sandcast resistors I suggest Mills resistors. A good source is Parts Connxtion>>> https://www.partsconnexion.com/mills-mra-12-resistors.html

Some brands make 6mfd caps. I have a pair of Erse poly film caps 6mfd (uF). PM me if you're interested. I have a number of caps in various sizes. FYI: many of the older caps AR used are marked with the AC voltage vs todays caps that are generally rated in DC, or have both the AC and DC voltage in some cases. 100VDC does NOT = 100VAC

USE THE LINK PROVIDED IN THIS THREAD. DOWN NEAR THE BOTTOM. https://community.classicspeakerpages.net/topic/13990-access-to-ar-drawings/