Callins capacitor?

[DonKu]

Why do Callins capacitors command such a high premium?

https://richelectronics.co.uk/product/callins-300uf-25v-audio-capacitor-vintage-low-esr-ol0382b

What's so special about them?

What's a good substitute?

[Haenk]

I'd assume you won't notice a difference if you put in a modern (quality) low-ESR cap instead. But the pricing for such a high quality part seems more than fair to me...

[bob91343]

For what it's worth, maybe not much, I don't think those are such great capacitors.  Especially the 'audio' reference, which preys on the common misconception that there is something to be gained by using fancy expensive parts.  Better to get the front panel gold plated.

Capacitors of satisfactory, and likely better, performance are available widely at much lower prices.

[tggzzz]

I'd assume you won't notice a difference if you put in a modern (quality) low-ESR cap instead. But the pricing for such a high quality part seems more than fair to me...

Define "high" and "quality".

[Bud]

...and define "Low" 

[DonKu]

The earlier Callins link was only for reference to give people an idea of the price and physical characteristics.

My questions actually pertain to a 100 μF 6 V Callins, which looks identical. It's used in a PAIA VCO module from the 1970s. The schematic's shown here:

https://crcomp.net/paia/2720-2A.png

C7 is the Callins. C6 is a plain vanilla electrolytic in a can. They both have a value of 100 μF.

Although the simpleminded answer goes through everyone's mind first, it doesn't add up. Why pay more for a Callins back in the day? Why not buy twice as many electrolytics in cans to get a better price break?
     Or, if Callins was the cheap alternative back then, why pay more for electrolytics in cans?

Perhaps the answer's as simple as the late John Simonton inheriting a pile of Callins. It's too late to ask John, but there's a PAIA forum, which may supply some answers, provided they process my registration. For the time being, the Callins will be substituted with a new electrolytic in a can.

[bob91343]

There are many factors influencing the choice of a component.  The obvious electrical parameters and price for instance.  You are spot on regarding the idea of a bulk purchase.  Another thing is that they may have elected to make sure of replacement compatibility due to dimensions, etc.  Electrolytic capacitors are notorious for being leaky and sloppy in tolerance and worse than useless at high frequencies.  Not to mention shorter life than most other components.

[cvanc]

Oh wow there's a PAIA forum somewhere?  One of the very first kits I ever built was 'The Gnome' micro synth.

I'm pretty sure most (all?) PAIA products were built with noncritical parts.  They were the discount synths back in the day.

[DonKu]

The forum's at https://paia.com/talk/ Caveat: my browser complains about the website's security. Meanwhile, my registration's still in the works.