[sdiy] External power connectors

[Colin Hinz]

On Thu, 2 Dec 2004, Don Tillman replied to Tom Arnold:

>   > On Thu, Dec 02, 2004 at 02:35:43AM -0800, Don Tillman wrote:
>   > > [SLAP!]
>   >
>   > Hey now, have you used these before?
>   > They are rugged, the contacts arnt horrid, and they are cheap.
>
> Sure, technically they're great in the sense that they'll meet the
> voltage and current requirements just fine.  The problem is that they
> have a huge amount of cultural baggage associated with them.  Mic
> connectors strongly suggest that that they're to be used for (wait for
> it...)  microphones.

I'm sure we've all heard the story about the guy who built his stereo
from scratch, and used rugged, cheap, readily available high-current
connectors for connecting the speaker cables to the amplifier.
Yeah......regular 2-prong AC power plugs. The story ends with a
house move, and someone helping him wire everything back up. Too
bad the helper didn't know about the "special" zip cords with
2-prong plugs.

But CB mike connectors in a synth context? That seems a whole lot
less dangerous. If these are verboten, then you'd better not be
using any surplus "circular military" connectors either, on the
off-chance that someome might jack a missile guidance system into
your Dark Star Chaos.

>   > Heck, I thought about going all old-school and using Cinch-Jones
>   > connectors.
>
> That's not bad.  Or Molex connectors.  Or AMP connectors.

If they're outside of an enclosure, they should have at least a token
attempt at mechanical protection. The Molex/Amp connectors are great
inside an enclosure, or on a lab bench. But designed for gigging? No.

(Okay, I confess that I've used all kinds of chancy connector schemes
in some of my gigs, but those set-ups were about as tidy as my lab
bench. It can really impress the hardware geeks in the audience,
but it's not something I'd want to *design into* something that I
was building for long-term use.)

>   > Major problem with using them is you have to cut a square hole
>   > for the jack.  Well, that and to be safe you'd have pins sticking
>   > out of the back of your equipment ( female on power supply, male
>   > on equipment, cables are all male/female )
>
> I think it's completely reasonable to drop the ejaculation metaphor
> for power supply cables.
>
> (Yes, I'm being completely silly and completely serious at the same
> time.)

Male-male cables are OK if you practice good cable hygiene. Don't
let any live ends wriggle around where you don't want some volts,
and you'll be fine.

And on a related note:

I recently got a bunch of 4-pin XLR connectors (both male and female)
at an unbeatable price. Now, I'd *never* use a 3-pin XLR for power,
but what about this odd form? I've never seen 4-pin connectors on
any kind of gear. Who uses them, and for what applications?

- Colin Hinz
  Toronto, Canada