I do not and will not leave the amps on 24/7 thinking it to be a complete waste of energy for absolutely no benefit. I'll take the $35.00 I'll save each month (thanks for the analysis, Steve) and buy a new SACD or LP.
My calculations could be off a little, as I found some different sources for electrical costs, and different electrical companies in different locales may vary. If you really want to know exactly what it is costing (or saving)
you, you can look at your electrical bill for your actual cost per kwh.
(W at idle X # hours X 30 days)/1000 = kwh per month
I do believe that solid state electrical circuits take time to reach thermal stability, but I would think that would be measured in seconds, not minutes. On the other hand, some "audiophile" vendors say that some solid state components take longer to stabilize than tube components!
Go figure. Most of us will go by what we hear or think we hear, and that's good enough. For those with
big guns, you may be pleased to know that the 28BSST2 consumes the same power at idle as the 7BSST2, 215W!