A post on AC Voltage Regulators - Why you might want one

Yep, @rlj there are a number of units which will cut power off if too low or too high for prolonged periods of time, including any Furman unit with SMP, but they are not voltage regulators.  To qualify it needs to alter the incoming voltage, instead of just cutting it off if too high or low.

This is not a feature everyone needs, per se.  Gear is designed to work reasonably well with a range of incoming power, but if your home power isn't that reliable or you want something that makes sure your gear is fed consistently good voltages a regulator is for you.

Why not? First, I’ll ask what the output impedance is? Is it going to limit an amplier’s response to quick current changes when the music changs?

Nothing will limit you more than having low voltage. Unfortunately many listeners think of the power from the wall as DC and not the 60 Hz AC that it is.

Lets say you have a big 20 Hz audio signal. Do you think the peak of the 20 Hz is going to somehow coincide with the peak of a 60 Hz signal coming out of the wall? Almost never.

The idea of instantaneous current limiting is really not a very useful way of looking at the performance of a power conditioner, or voltage regulator. A better question is: Will it keep the voltage stable even under demanding conditions inside my house? Yes, yes a voltage regulator will.

In this case, the voltage regulator will make your AC wiring appear as if it has less impedance than it had otherwise, to a point, of course.  The Furman I used as an example only works within the sample carts up to 12 Amps.  For my 110 WPC A/AB linear amp + DAC + Streamer that's about 5x more than I ever use.

Hi @immatthewj 

It can be pretty overwhelming when looking at a brand like Furman to pick the right products.

For an audiophile the basic requirements are LiFT and SMP.  After that, voltage regulation.  Personally I use a Furamn Elite 15 PFi on my video stack, and a separate, simpler unit  + voltage regulator on my audio stack.