John,

Yes, UPS systems do clean up the power very well when converting AC to DC then back again, but again most filtration systems on good surge/spike protection system will do the same thing, except that the UPS is louder (as you noted).

In regards to providing a constant 120VAC to an amplifier, this would be a valid point if the amplifier used a regulated power supply that is fixed @ 120VAC. However, almost all power supplies for amplifiers use transformers that have multiple taps on them that will draw current based upon what the incoming voltage is (usually between 100VAC & 125VAC).

The problem with hooking up a good amplifier to a UPS is that unless the UPS is capable of allowing sufficient current draw through it (in large bursts), the amplifier will react just like it does without a UPS. Remember, these UPS systems are not car batteries nor do they have capacitors to allow quick discharges of large current without effecting other systems.

Also, most high capacity UPS systems don’t have great surge/spike protection. The APC 3000VAC unit has good, but not great protection and is not impervious to lightning.

In the end, unless your voltage is down around 100 to 107 volts ac, then I would stick with an item like the Surge-X.

There are other items to discuss in regards to the above, but on a side note I have a friend who designs amplifiers for a major electronics company and his golden rule is to always allow amplifiers to run with as little resistance between them and the power grid, placing a UPS in between the two is just not something he would ever do (and he has tested this with bench equpment).

Feel free to ask any other questions if you like.

Regards,