How important is S/N Ratio....?

Eldaford - Jet plane was a joke but I think you mixing landing and taking off. During landing they are very quiet.

I read once that 120dB was equivalent to standing next to jet engine during take-off (should I say running very fast). To visualize what 120dB level is try to imagine large GE Jet engine at full power in front of your door (neighbors might not care too much for it).

"I maintain that above a damping factor of 50 then you gain next to nothing. In fact, extremely high damping factors may be indicative of very high amounts of feedback and just like an amplifier with a specification from 10 Hz to 400 Khz I am wary of these kind of amps"

Shadorne - I agree 100%.

Sane designer would try to design an amp with not more than few percent THD before feedback and then improve it using feedback to only about 0.1%. Finaly he would limit bandwith to what amplifier had before feedback was applied to prevent TIM. 100kHz bandwith as a result might be nice to prevent phase shifts but 400kHz is unnecessary and might be harmful.

Damping Factor is often limited to about 100 by the choke in series with the woofer. Also DF measured in static condition doesn't mean much. Transient response of power supply (due to usage of good capacitors like slit foil etc) might be more important.

As for "More Power" I would suggest "Less Power". On average 200W amp doesn't sound as good as 100W amp that cost the same and is only slightly louder (it needs 10x power for 2x loudness).

Magfan - large dynamic range of 120dB or more is absolutely necessary to reproduce real sound of the large jet planes taking off when I see it on TV.

Wavetrader - if you do this yourself be sure you know what you're doing. Installing low ESR caps with certain voltage regulators might cause oscillation.

Wavetrader - that's good!

Clio09 - more headroom is always better if you can afford it. If you have let say $1k to buy an amp would you be better with mediocre 1kW amp or great 100W amp. 1kW amp should be twice louder but not always. Amps are rated for nominal power and 100W amp might have very large peak power being designed by good conservative company. 1kW amp that cost the same as 100W one will have most likely worse parts since power supply, case and heatsinks have to be 10x larger and something has to make-up for their cost.

Much worse if you choose SS amp over tube amp that you like only because of 200W over 100W (and 200W tube is too expensive). Another example might be selling 50W class A amp to get 100W class AB amp etc. There is a very little difference in sound level between 100W and 200W.

Wavetrader - as far as I know electrons don't flow. Electric current is an electromagnetic wave (while electrons move only about 1/2" per second) which is also difficult to explain using example od stacked balls since space between electrons is in order of 100000 time their size. One theory says that electrons emit photons but this doesn't add up if we assume that photons can move in any direction. It is probably better explained here:

http://www.geocities.com/natureoflight/pg4.html