This may not be the best forum for what follows, so if anyone knows of a more suitable hardware-oriented forum I'd be kindly obliged for the information.

The 3.5mm audio connector is a well-accepted standard, and a competent design if well manufactured. In my experience most of the plugs, and especially sockets available to hobbyists do not meet this criterion. The reason is easy to discern, and is a geometric challenge in every connector design using curved - especially cylindrical - terminals. Ask yourself: "What is the area of contact between a cylinder and an abutting surface?" The answer is "a geometric line" which is one-dimensional and has ZERO surface area.

The main flaw in the cheaper connectors is a single terminal of thin nickel-plated steel that passes ACROSS the cylinder, thereby reducing the geometric line to a geometric point - nothing. They ALWAYS give unreliable contacts that must be "juggled" in order to get a useful connection. The best available in my experience are the flat ones with a transparent upper case: a quick peek inside shows why.

Does anyone know of a manufacturer with soundly designed 3.5mm products?

 

If it ain't broke why fix it?

 

Electrical contact is a remarkably complicated subject when considering real contacts rather than perfectly shaped and infinitely smooth ones that your discussion supposes.
See paragraph 3.1.2 here: http://s1.downloadmienphi.net/file/downloadfile6/192/1385058.pdf

 

perfectly shaped and infinitely smooth ones that your discussion supposes.

Hmm. Maybe I wasn't quite explicit enough. I was arguing AGAINST the assumption of "perfect connectors" and asking for consideration of practical alternatives.

> If it ain't broke why fix it?

It IS broke, in my experience, and I'm seeking fixes.

 

For those still uncertain as to what I'm on about, when I need a reliable connection I use the common-or-garden rectangular pin types:

http://www.jst-mfg.com/product/detail_e.php?series=199

One of the main reasons why USB connectors have remained so popular is because they DON'T use curved-surface connectors, but sliding (removes oxidation) flat-surface terminals. If you want further proof, examine Deans Plugs and related types from this perspective.