What (if any) are the benefits of isolated in/out jacks?

[skiraly017]

Any merit or boutique hooey?

[Paul Marossy]

On stompboxes, I would say that it is very little to no benefit - in my mind, you want to have a metal box that acts as a EMI shield, so isolating the jacks makes no sense to me. I suppose some people may think that it would eliminate ground loops or something.

On a tube amp, isolating the input & speaker jacks from chassis ground can help quite a lot with keeping hum at acceptable levels.

[Gladmarr]

I can see it if you were doing stereo outputs and you wanted to keep away from ground loops between amps, but you'd have to have an actually isolated o/p for that.

[R.G.]

The best hooey is hooey that contains embedded granules or flecks of truth, whether or not that's of any consequence.

Like having a sign with lightning bolts on it that says "Danger! One Million Ohms!".

Jacks with isolated sleeve contacts are useful in some equipment. The essence of an isolated sleeve jack is that you the builder get to pick where your ground connects to the outer chassis, not have it determined for you. This can be invaluable in big setups. Crucial even. The smaller and simpler the power and grounding arrangements are, the less you need it. Some incredibly high gain pedals might need it. Most do not.

Little bright, shiny flecks of truth...

[rockgardenlove]

Well, if you buy from Aron, the plastic ones are cheaper, and seem pretty well built too.
That's why I've been using some.