Oil caps better?

[davidro]

G'day all

I'm hearing from vintage fans that oil caps are better sonic-wise.

It seems some people want to make sure when they buy early AR speakers that they come with the old original oil caps.

It puzzles me as I thought these oil caps gotta be so out of spec by now after a few decades.

But then again, I wondered if people still do make oil caps - yes they do but 10uF would cost you like $115-$145!

So, if that's the case, am I better off opening up my AR-3a and see if the old oil caps are still within spec, and if so, wire them back?

[dynaco_dan]

G'day all

I'm hearing from vintage fans that oil caps are better sonic-wise.

It seems some people want to make sure when they buy early AR speakers that they come with the old original oil caps.

It puzzles me as I thought these oil caps gotta be so out of spec by now after a few decades.

But then again, I wondered if people still do make oil caps - yes they do but 10uF would cost you like $115-$145!

So, if that's the case, am I better off opening up my AR-3a and see if the old oil caps are still within spec, and if so, wire them back?

Hi there

If you can find a heating/air conditioning supplier near you, they usually carry fractional horse power ( FHP ) motors and running/starting oil capacitors.

They would be about $10.00 - $20.00 CDN each.

Here at least in Vancouver we have 120 V 60HZ usual hydro power and they are used here for direct drive fan motors, for just one application.

The direct drive motors are sold here less the capacitors and you buy the appropriate size for the job.

I bought several sizes for different FHP d/d motors over the years.

Even a service shop that repairs smaller horse power motors should have a selection.

[Carlspeak]

Chances are pretty good you won't find oil caps in your 3a's. Most likely they will be Compulytic NPE's or their predicessor, the Chicago Industrial "cheese block" paper/wax caps. The earliest AR's had what I believe are oil caps which look like tin cans wrapped in a bundle - something you'd not want to get caught with by the TSA boarding a plane. :-))

I have to wonder though, about the lore of vintage stuff tainting (biasing) folks's opinions.

Here's a link to a quite throrough cap comparison study that includes recommendations on caps for specific applications (i.e. amps, speakers, etc...).

http://www.laventure.net/tourist/caps.htm

[dynaco_dan]

Chances are pretty good you won't find oil caps in your 3a's. Most likely they will be Compulytic NPE's or their predicessor, the Chicago Industrial "cheese block" paper/wax caps. The earliest AR's had what I believe are oil caps which look like tin cans wrapped in a bundle - something you'd not want to get caught with by the TSA boarding a plane. :-))

I have to wonder though, about the lore of vintage stuff tainting (biasing) folks's opinions.

Here's a link to a quite throrough cap comparison study that includes recommendations on caps for specific applications (i.e. amps, speakers, etc...).

http://www.laventure.net/tourist/caps.htm

Hi Carl

Thank you for that link.

What an eye opener.

We may quibble about spending $50.00 for a handful of caps for speaker crossovers.

I'm going to run right out and buy the Duelund silver capacitor at $5,775.00 each U$ and convert my Dynaco A-10's.

I am certain that I will hear a difference.

[Carlspeak]

Hi Carl

Thank you for that link.

What an eye opener.

We may quibble about spending $50.00 for a handful of caps for speaker crossovers.

I'm going to run right out and buy the Duelund silver capacitor at $5,775.00 each U$ and convert my Dynaco A-10's.

I am certain that I will hear a difference.

I did recap a Polk SDA-SRS for a guy who provided the parts which included two Duelund 6 uF tweeter caps. He told me he spent about 3 grand on just the parts and needed me to figure out a way to install them all. As you can see in the pic below, the cap bundles were so heavy, I had to add wooden support colums on each end of the xover board to keep it bending to breakage. The flat thin caps are the Duelunds (4 in each xover). There were also some Sonicaps (Polkie favorites) and solens were relugated to the less critical parts of the xover. The 'smoke stacks' are Duelund high-end resistors. That job sure was a challenge.

[davidro]

Lol that's interesting. To think those Solen caps were a luxury in my restoration!

BTW, so these blue cans aren't oil caps?

[kirk57]

No, those are regular electrolytics. The capacitors DynacoDan refers to are also called motor run capacitors, and are available on Ebay. Whether it's going to make a difference is debatable...

[genek]

That job sure was a challenge.

So was it any challenge to be able to hear a difference in the sound for all those expensive components?

[Carlspeak]

So was it any challenge to be able to hear a difference in the sound for all those expensive components?

It wasn't for me. I simply turned over the upgraded xovers to the owner for him to install and evaluate. Eventual feedback was very positive. How could it not be? :-))

[genek]

It wasn't for me. I simply turned over the upgraded xovers to the owner for him to install and evaluate. Eventual feedback was very positive. How could it not be? :-))

Work to customer's specs with customer taking responsibility for performance results. Sounds like a perfect contract to me.