AR 2ax capacitor type?

[Guest Droog]

Wanted to know what type of capacitor was used in the early 2ax, serial number 9,500 circa 1964-65. They sound fine and don't want to open them up for no reason. I've heard AR switched from oil filled steel caps to the less durable wax covered paper type in the mid 60s.

[charger3834]

I have some circa 1965-1966 AR-2ax's. The serial numbers are in the 16,000's. They have the wax paper covered caps that were very popular in many 1960's and 1970's models. I have never seen a bad one. They may change in value a little, but I seriously doubt it's anything a collector should be concerned about. If it sounds fine, I say it is fine!

[tysontom]

>Wanted to know what type of capacitor was used in the early

>2ax, serial number 9,500 circa 1964-65. They sound fine and

>don't want to open them up for no reason. I've heard AR

>switched from oil filled steel caps to the less durable wax

>covered paper type in the mid 60s.

The caps used would be the Chicago Industrial plastic-encapsulated, paper dielectric (not wax-covered) caps. There was some wax impregnated inside the dielectric portion of the cap. These caps are really pretty durable, and they are pretty well sealed against moisture so far as I can tell, but I have read (here) where there is concern about these caps developing leakage problems later on. I have really not had any experience with these caps going bad, although some have complained of problems with them.

If your speakers sound fine, I simply would not go in there and start changing things. "Change for the sake of change," is not really what you want to do so long as these speakers still work properly. Listen for any strange distortion or loss of output -- in the context of that speaker's relatively reticent personality anyway -- and then determine if there is a problem. A bad capacitor will manifest itself in many ways, but usually there is increased distortion, abnormally large loss of output, or that sort of thing.

--Tom Tyson

[Guest Droog]

So, it sounds like it was just the AR 1, 2, 2a and early serial numbered 3's that used the oil filled caps. I only ask because in a earlier post about capacitors, it was stated that the oil filled were more stable and it was recomended that speakers having factory paper caps - replace them. I'll stick with the more recent advice of 'if it's not broken-don't fix it' ! My all original 2ax's sound very nice-

[tysontom]

>So, it sounds like it was just the AR 1, 2, 2a and early

>serial numbered 3's that used the oil filled caps. I only ask

>because in a earlier post about capacitors, it was stated

>that the oil filled were more stable and it was recomended

>that speakers having factory paper caps - replace them. I'll

>stick with the more recent advice of 'if it's not

>broken-don't fix it' ! My all original 2ax's sound very

>nice-

Yes, that's correct. The early AR-1s, AR-2s and AR-3s (perhaps the earliest AR-2as from 1959) did use oil-filled caps. There were at least two reasons for this: (1) oil-filled caps were one of the industry standards during the period leading up to and following WWII; (2) there were a lot of war-surplus parts available for a period of time in the forties and early fifties, and I think that many companies took advantage of this fact.

To be honest, I have had a few minor problems with crossovers with the oil-filled capacitors -- somewhat more than than with the later Chicago Industrial versions. A lot of that may just be due to the very old age of some of those early crossovers.

--Tom Tyson