Do you leave CD players with tube outputs on?

A1,

Thanks a lot! I am glad that you accomodated my request.
Thanks for your time answering my inquiries. I learned something today!

Best regards,

Abe

Tubes reach the point of normal operation faster than semiconductors thus require shorter time to worm up (for the small signal tubes near 2min. Why bother to keep them on??

I think a lot depends on your unit. Some take longer to warm up than others, also some are a little more "blunt" with how they power up. If Telefunken 12ax7s last 10,000 hours, you do the math....
I tend to leave my system on all weekend if I'm listening a lot. But, if I'm not going to listen for a day or two, it gets turned off.

From conrad johnson's web-site........

"To obtain maximum tube life, vacuum-tube products should be switched off when not in use. A good general rule for is that if you will not be listening for more than an hour, turn any tube component off. Conrad-Johnson solid-state preamps (including Sonographe and Motif), on the other hand, are designed to be left on at all times. We recommend switching power amps off when unattended and over night."

How long do tubes last?
A. That varies depending on the type of tube, the number of hours of use and the type of use they have had. Typically tubes should last, on average, about 1500 hours before gradual degradation of performance becomes noticeable. This translates into two to three years if the unit is turned off when not in use. Usually tubes will continue to be functional for a long while after this, but sound quality will be reduced and noise levels will increase. In power amplifiers, the input tubes are most critical for sonic performance. If output tubes are not causing problems, they can be replaced every other time.

Most preamps and CD players/DAC's idle in the 10-30 watt range, and over time, it almost certainly is more expensive to keep gear powered up than to lose small-signal tubes through on/off operation. But retubing with some gear is not convenient, tube failure is often gradual and annoying to listen to because of the tendency of tubes that are dying to act up, and there are other parts in equipment, particularly processors in digital gear, that have to be left powered up if they are to sound right in a high-end two channel system (try listening to cold digital gear through a first-rate triode amp or something like a darTZeel on revealing speakers - it sounds awful). I don't like f'ing with tubes and I hate the sound of cold gear, so I leave everything but my tube amp powered up.