However, an isolation transformer is not likely to cause problems.......
Let me explain the distinction between devices that are likely to cause problems and those that aren't....... in general terms.
OK, let's start with the wiring in your walls. All wire has some resistance - and resistance acts to "constrict" or "restrict" current flow to a degree that depends on, well, the amount of resistance.
And this is an especially important issue for big power amps, which use a lot of current, and "notice" when their supply voltage drops because the current is constricted.
Now, luckily for all of us, this isn't really a problem with wall wiring because power circuits use heavy wire, with relatively low resistance.
(And, with really big amps, we might still use a separate circuit so we don't have to "share wires" with other stuff.)
Now let's move on to power
FILTERS.
A typical power filter includes one or more inductors in series with the power line, and one or more capacitors "across" it.
An inductor is simply a short length of wire, wound in the form of a coil, which may simply be wound around a plastic spool, or which may contain a ferrite or steel core to increase its inductance.
In either case, in the context of this discussion, it's a length of wire.
That wire is probably only a few feet long and, even though it's often thinner than what's in the wall, it still doesn't have much resistance.
This means that it DOESN'T cause a "significant constriction" to our power current, and it can probably withstand a short power surge far beyond its ratings.
(In order to seriously overload it, you actually have to push enough current through it long enough to overheat it... )
Now, how about SURGE SUPPRESSORS.
A typical surge suppressor is made up of one or several MOVs (metal oxide varistors) "across" the line.
The active components in a surge suppressor aren't "in line" with the current supply at all - and so don't "constrict it".
Many devices combine both of these two.....
And let's mention ISOLATION TRANSFORMERS.
Isolation transformers do several things.
Because they have inductance, they act as a filter; but they also isolate the power coming in from the power going out - which tends to reduce ground issues and eliminate "ground loops".
However, internally, a transformer is two coils of wire, wound on a common core - usually steel or ferrite.
And, for the purposes of our discussion, most transformers, while they may use somewhat thin wire, still have pretty low resistance.
And, most transformers are conservatively rated, and their power rating is related to how much power it takes to make them overheat.
(So most transformers can actually pass a LOT more current than their rating for a short period of time.)
If your amplifier demands 200 watts, and your transformer is only rated for 100 watts, it will probably deliver it for a fraction of a second with no problem at all;
just don't do it for too long or it will overheat... so don't get carried away.
In other words, unless an isolation transformer is very undersized, it probably won't produce a "significant constriction in power flow".
(This will vary, so you're still better off using a properly rated isolation transformer.)
And now, finally, POWER REGENERATORS and REGULATORS.
A power regenerator doesn't simply "pass" current; it actually converts the AC input into DC, then used that DC to run an amplifier, and that amplifier then puts out "new power".
This is also what happens with your UPS when the lights go out - it takes power from the battery and uses it to create AC power - like an amplifier amplifying a 60 hz sine wave.
The point here is that, since they actually "make" power rather than simply pass it, both of these devices are quite capable of "running out" of power if you ask them to deliver too much.
If you have a simple power filter, or a surge suppressor, rated to deliver 10 amps, asking it to deliver 12 amps for a minute, or 15 amps for a second, probably won't be a problem.
BUT, if you have a power regenerator rated to deliver 10 amps, it might or might not deliver 12 amps for a minute, and will probably limit if you ask it to deliver 15 amps for a second.
(And, if this happens, then it will be doing the exact opposite of why you bought it, it will be FAILING to deliver the steady power that you want to your amplifier.)
And that's the big problem with power regenerators and regulators.....
They're
MUCH more expensive than a simple filter or surge suppressor, and, if you want to avoid problems, you really
NEED to have one that's rated to deliver all the power you even might need.
So, for example, a pair of XPA-1's will probably run cheerfully on a 15 amp circuit, and even share it with some other components - and only ever demand more than 15 amps for a split second.
And connecting them to a power filter rated at 10 amps would probably be OK as well (although we can't advise it) - because, while they might draw more than that for a split second, it won't cause any problems.
However, if you want to use a power
REGENERATOR, you really need to use one rated for the full current that the amps
MIGHT draw...
because exceeding its max rating for even a split second now and then
MIGHT be a problem.
(This is why, while I personally believe power regenerators to usually be a total waste, if you do want to use one, you should limit it to powering low-power devices like preamps and signal sources.
These devices both require a lot less power, which means you can use a moderately powered power device, and are more likely to benefit from "ultra clean" power. )
A lot of the comments and questions I'm seeing seem to conflate "power filters", "surge protectors", "power conditioners", and even "power regenerators".
Power filters and surge suppressors are relatively simple devices - and so, unless they're simply badly designed, or you're using one that's drastically underrated,
they tend not to have any negative effect on things. However, power regulators and power regenerators are complicated, and there is a lot of potential for
things to go wrong... or for the device to have limitations that may affect what's connected to it.
(For example, a "10 amp power regenerator" is actually a 1200 watt audio amplifier - amplifying a 60 Hz sine wave signal; if that amplifier "clips",
whatever you have running on it is going to have a problem. And, if your load needs 20 amps, even for a split second, it probably can't supply it.
In contrast, a 10 amp power filter is several turns of heavy wire wrapped around a ferrite core, and a few capacitors; and, as long as the wire is heavy enough,
and the internal connections are solid, it probably isn't going to bother anything.)
Unfortunately, terms like "power conditioner" are used to describe a wide variety of devices, and it is the more expensive among them that
tend to be complicated, and to be likely to have limits that can affect the equipment connected to them.
And than a few people like me run ALL my low current stuff thru a small (400va or so) Isolation Transformer. yet another can of worms.
