To Power Down, or Not to Power Down


My pre-amp (Rogue Audio 99) and amp (Cary CAD-120S MkII) are both tubed. There are days when I will have a listening session for about an hour followed by a two or three hour break followed by another listening session (or two). If the next session will be within an hour or so I leave the system up, but I'm not sure what to do when the interval between sessions is longer. My questions are...Is it better for the equipment if the system is powered down between sessions that are more than 2 hours apart, or should the system be left up? Is there a detrimental effect on tube life by cycling power up/downs in this short a time period? I would prefer to power down for simple green reasons, but the cost of eight KT88's failing prematurely would be far greater than the increase in my electric bill. I would like to know what others in a similar situation do?
Jerry
jerroot
Polk432-
My unit was manufactured as a MKII, not an upgrade, but in the end I don't think there should be any differences between the two. I would think that Cary would do everything to make them indistinguishable from one another, but a call to them can get you an answer to that question. From all I've read, the upgrade seems to be well worth the investment. Here is a link to Anthony Cordesman's Dec. 2010 review in TAS which makes some comparisons to the MKi and MKii.

http://www.avguide.com/review/cary-slp-03-preamp-cad-120s-ii-power-amplifier-tas-208

Thanks for the input, all.
Jerry
Leave them on based on your post. You will wear out the tubes faster by powering them on and off throughout the day.
Jerroot, thanks for your help. Maybe I'll get the upgrade since I'm shipping it back to Cary anyway. I'll take a chance, why not Columbus did. Thanks again the article was interesting and I should be set with years again. I wonder how to keep the room cooler in the summertime, but I had a V12R and wondered how to keep the room cooler in the wintertime. The CAD 120 sure runs much cooler.
I spoke with Cary. It's ok to power down. Preamps don't matter as much. Jerroot, Cary suggested that since I have the SLP98P it would be better to get Cardas Caps and new Hexfreds, than to have the gain and feedback altered since the SLP98P has such a high gain. They recommended I not get the MKII upgrade in my situation. Thanks again for the avguide info.