Leave solid state amps on? Or turn off everytime?

As to a response from a EE - here it is - When power is first applied to a circuit,or cut off, all sorts of transient events occur that never reoccur as long a the system is on. Very high currents and voltages are present that die out quickly. Even aside from the thermal changes that everyone is concerned with, once a steady state is reached there isn't a whole lot of difference in the stress on the components that if the system was off. For this reason, you probably will extend the life of the individual circuit components by leaving a system on all the time - more true with solid state than tubes.

Tvad - In practical terms - it really doesn't matter. You will extend the life by leaving the system on, but, as with most questions that come up on this site - it is likely a meaningless difference. Well designed solid state equipment lasts a long time. As to your example - you may only get 40 years out of an amp that you turn on and off everyday - but get a whole 41 years out of the equipment if you leave it on all the time. What is most likely to wear out will be electromechanical components - for eg. a power on relay. Transformers, transistors, resistors and, despite everyones obsession - caps both electrolytic and otherwise, will outlast the em components. I too have seen an awful lot of equipment that was around unrepaired and unmodified for decades.

Danyal711: I can give you an example of the measured difference in a mcintosh MC400 - on but with no signal applied it draws around an amp. Driving speakers on big orchestral pieces with peaks reading 400 watts on the front panel meters the draw goes to around 6 amps.

As to your question about power regulators. First, ripple is not something addressed by a power conditioner. Ripple is the quasi ac component left on filtered dc after rectification, a more proper description is the charge discharge waveform; at twice line frequency for full wave rectification. Power conditioners are used to filter EMI riding on the ac line - and typically to compensate for undervoltages and protect against overvoltages. Check the specs on your equipment - my guess is it will work fine over the range of fluctuations of your line voltage. For example, if your line voltage fluctuates 10 percent or less around the nominal. Do you need one? Depends on your power but probably not. It is wise to have catastrophic surge protection - for dealing with induced lighting for example. But you don't have to buy a power conditioner for that.

If you have a lot of power problems - and they are fewer than the number of line conditioners sold, then you may want to look into a power conditioner, particularly if you have a lot of momentary drop outs. But to really get the benefits - choose one that is sold by a company to businesses to protect data equipment or from such same company for audio use - but get one with fast catastrophic protection and one that will quickly produce a clean ac waveform from batteries in the event of say a 2 to 3 second power drop out - an event not uncommon during high electrical usage times in the summer months. Otherwise just get an inexpensive surge protector. I have never had the need for more than an inexpensive surge protector. One imporatant aspect, if you have your equipment hooked up to an antenna or cable leaving the house, particularly if the cable goes overhead, protect against induced lighting on that antenna or cable line - such catastrophic potentials are much more likely to enter your system via such routes than via your ac.