Tube preamp reliability vs SS?

Myself and other geezer guitar amp users (in my case since 1962, but not professionally before 1967) were mostly clueless about preamp tubes and abused the hell out of tube amps with no MOLLYCODDLING. Whatever that means…very rare for a good tube amp to fail, even when abused 6 nights a week for several sets a night…my old Fenders…friggin' bulletproof.

You can't abuse a tube preamp via the input signal :)

I play in a band as well and while I have technical skills, the idea that a semiconductor is going to fail on the road is not a happy thought- that bit of equipment is going to have to be dealt with in a shop, not on the road. OTOH a tube can go and its simply a matter of plugging in a new one.

I play metal and heavier music at home and find that tubes do that extremely well. Just a FWIW- electronics generally speaking does not care what material you put through it- if its properly designed it will be as good for metal as it is for classical. 

Tubes wear out because the vacuum degrades and the filaments burn up at higher oxygen levels in the tubes. Since you cannot keep a good vacuum forever, this is inevitable.

Solid state devices can fail as well, but this is more determined by the original design and support circuitry than the devices themselves. I have Tektronix measurement gear (such as amplifiers and O scopes) that were built in the late 60's and early 70's using the earliest solid state transistors that still meet factory performance specs to this day. That is because the power supplies and bypassing components were of military or high commercial specification, and voltage transients from the power line did not get in and destroy those transistors.

While you can perhaps overload a tube circuit without a big issue, overloading a solid state circuit can spell disaster for a semiconductor. Under certain conditions, overload and secondary breakdown in a transistor is measured in microseconds. No fuse can protect a solid state device unless the device was designed to withstand the eternity of time it takes a fuse to blow.

Heat is another killer for solid state devices. Failure lifetimes are exponentially reduced at high operating temperatures. High temperatures enhance conduction mechanisms in SS devices that can lead to avalanche conduction and catastrophic breakdown.

So, if a solid state design is done properly to keep heat down and transients controlled, solid state devices can last for decades. They're lifetime may be dependent on replacement of certain components (like capacitors), which if fail, will take the solid state components with them.

Corrosion is something that affects semiconductors that does not affect tubes. This might take a few decades, after which its a very good bet that the device will be obsolete. Anyone that services audio equipment knows this all too well!

I have had a cj Classic 2SE for a little over two years and it's a great preamp....I love the sound it produces....It replaced a McCormack RLD-1 which was nice, don't get me wrong...  The Classic blows it away so it was easy to give up remote volume and switching for something as stripped down as the Classic.  Sound quality is paramount so for me it was easy to give up the feature set of the McCormack.  I am using it with a pair of Quicksilver Mid Monos and it is a killer combo.   Both have been rock solid,  except for a tube here and there....My previous amp was a McCormack DNA 125 which is a great amp, no doubt but the Classic/ Quicksilver combo sounds better, just won't play quite as loud but I never push it loud so it's not a problem in my small room.