IMO the bottom line on the many tradeoffs that are involved, which certainly figure to be dependent on the designs of the particular components as well as on the particular usage patterns, simply comes down to common sense:
If the system is just being used a couple of days per week, as is the case here, and especially given that the system includes an amplifier that runs hot even in standby mode, as well as a hot-running preamp, turn it off on the rest of the days.
In situations that are at or near the other extreme, where the system is used multiple times on most days, and where everything in it is cool-running, leave it on continuously.
In circumstances that are in the middle ground between those extremes, and if the manufacturers of the particular components do not provide any specific guidance in the manuals or otherwise, flip a coin :-). It may not matter much either way.
Regards,
-- Al
If the system is just being used a couple of days per week, as is the case here, and especially given that the system includes an amplifier that runs hot even in standby mode, as well as a hot-running preamp, turn it off on the rest of the days.
In situations that are at or near the other extreme, where the system is used multiple times on most days, and where everything in it is cool-running, leave it on continuously.
In circumstances that are in the middle ground between those extremes, and if the manufacturers of the particular components do not provide any specific guidance in the manuals or otherwise, flip a coin :-). It may not matter much either way.
Regards,
-- Al