Cary SLP 05 - When To Replace Tubes?

So just for fun maybe before you start changing out all your tubes try removing the new power cords and USB/Spdif reclocker and see what happens? You can do this immediately and get results plus it's free. Good luck!

I would expect 5000 hours.  You need to get them tested.  The rectifier will last even longer.
Blame the sound on the power cord. They do need break in time.

OK i have swapped the tubes.

So far it seems to be the tubes (I still have to swap the old ones back to reconfirm) but what I was getting was a muddier sound overall with less pitch definition which made the deeper bass from the power cords and the USB/ SPDIF reclockers seem boomy. Everything has tightened up now, soundstaging has improved as well as space between instruments and air.

So if I swap the old tubes back and confirm it is the tubes, I am guessing I will have to change all 6 at the same time? Or can I economise and change the ones that need changing by swapping out pairs at a time and replacing only those that are weak and causing the problem? I realise if I have a tube tester it would be easier but unfortunately I do not.

Also, when do I need to change the rectifier tube? What are symptoms of its end of life?

Thanks

Assuming you are running fully balanced, you can change out the tubes in 2 steps. 1,2,4,5 as a matched quad and 3 and 6 as a matched pair. 

"Also, when do I need to change the rectifier tube? What are symptoms of its end of life?"

My SLP05 came shipped with a Sino rectifier. When it went bad it blew the fuse when I turned on the power supply. I replaced the Sino with a Create Synergy recifier (twice). When the Create Synergy rectifiers went bad the bass became loose and wooly, the soundstage became indistinct and lacked  focus. The Matsushita rectifier I have installed now has been performing flawlessly and sounds much better than the Sino, Create Synergy, Genelex Gold Lion and Phillips Miniwatt (black base) I had installed before I purchased the Matsushita. 

Jazz