switching between two amplifiers; issues of power

As indicated on pages 15 and 24 of the ICEpower300AS1 datasheet its + and - output terminals both have 27.25 volts of DC on them. (A number of other older ICEpower modules are like that). So **if** the physical arrangement of the connectors on the amp makes it possible for either conductor of the speaker cable, when being connected or disconnected while the amp is turned on, to briefly but simultaneously come in contact with the output terminal and either the ground sleeve of a nearby RCA connector, or the metal release tab of an XLR connector, or the chassis of the amp, or the shell of the plug on a connected interconnect cable, damage would be very possible.

Regards,
-- Al

Very helpful. Many ways to cause damage with wires floating between amps in the power "on" position, although technically no harm arises in having the amps on without interconnects. 

Always power off when making connections like this. Then it will be okay to leave on with nothing connected.

The amp btw was fine. For every watt of power you get about a watt of heat. Touch a 300 watt light bulb for reference. That's how much heat the amp has to dissipate, one way or another. If you run one 300 watt amp so hard it gets hot then guess what? Next one will too. Maybe not where you put your hand, but that same heat does have to go somewhere. 

@millercarbon 

So, the first amp is the lovely STA200, outputting 80wpc, and I've got it pushing a 4ohm nominal, down to 3.1 load. The amp does fine at modest volumes. I've been posting about this, from a variety of angles, for the past several weeks. It's a struggle because the amp's sonics are about as good as I would expect to do, for under maybe $3000.00 I could be mistaken and I'm eager to hear some suggestions, but I can't go the direction of tubes in this very hot climate, so we are talking ss or class D suggestions.

Back to the Nuforce: it is not recommended to run this amp on 4ohm speakers, but when I bought my Tekton's I was told the speakers run so easily it shouldn't be a problem. 

I am understanding that class D 300 wpc will run quite a bit differently, owing to crazy high efficiency, compared to SS in the Nuforce. 

1 watt into an 80% efficient amp would seem to yield 1/5 watt in heat?

Hey.  I still own some IcePower 250 modules.

1 - Do not change anything on the input while the amp is on. This includes powering up/down the preamp.

2 - Yes, you may disconnect speaker cables and reconnect them while the amp is on, but suggest muting the audio since you could feel a tingle, or accidentally short the connections.

3 - IcePowers take a very long time to warm up, like 48-72 hours, but they don't cool down in a minute.  You can leave them on except for the short period of time you are disconnecting any inputs OR turning a preamp back on.