How do I know when to replace Melos SHA - 1 Tubes


I purchased a used Melos SHA-1 Pre-Amp over 5 yrs. ago, since then I have upgraded my Amplifier replacing the Rotel with the ARC VT 100 MKII..How can I tell if my tubes need t be replaced? I do listen to quite a bit of vinyl & I'm using the McCormick Phono Pre Amp. Should get a new PreAmp? Is there a Pre Amp that will work well with the ARC Amp which has a phono stage..Or should I continue using the Melos? How much for new Tubes; which tubes & where can I find them?
The rest of my equiptment is:
ProAc 2.5 Speakers
Meridian 518.20 CD player
PS Audio P300 Power Plant
hlt

Showing 1 response by unsound

You'll never really know for sure, it'll just always be in the back of your head, distracting and gnawing at you. The seeds of a conspiracy planted to induce paranoia, overtake your senses, and the world as you previously knew it.....or thought you knew it?

:-)Just kidding!...............................or am I? :-)