"Keith G" wrote in message

"Iain Churches" wrote in message
...

"Dave Plowman (News)" wrote in
message ...
In article ,
Iain Churches wrote:

Most devices that suply phantom power, do so to
XLR sockets only. But there are exceptions. I have
a Ducane supply where the DC appears on the
TRS connectors also.

So it is good practice *always* to ensure the phantom
is switched off before inserting or removing any
connector. That way you won't get caught out.

I've seen plenty of installations where the console
supplies the phantom powering so that goes via the
jackfield.

Why does it need to go to the jackfield?

To avoid making super-duper transients when you plug and unplug jacks in the
jackfield?

If the phantom power bypasses the jackfield, every mic that is plugged into
a wall plate constantly receives phantom power, whether it is jumpered into
the console or not.

If the phantom does not bypass the jackfield, every mic that is plugged into
a wall plate eceives phantom power only when it is jumpered into the
console. If you unplug and plug jumpers on the jackfield, the phantom is
applied and removed from the mics. Applying and removing phantom power from
a mic usually creates some pretty big transients, especially if the mic
relies on phantom power.

The mic inputs
are usually XLRs on wall boxes, and hardwired to the
console inputs.

But what we are talking about here is a small preamp/FX
unit that Keith has, which also supplies phantom.

Which is switchable.

Which is only applied to the XLR input, when it is turned on.