Does equipment get old?

I ask this question not in the metaphysical sense (that we get tired of it) or in the sense of equipment becoming technologically obsolete. Instead, I ask whether amplifiers and preamps (SS or tube but my particular case is tube) get so "old" that they no longer work the way they were meant to. This may sound silly (the other side of "breaking in" cables?) but can the physical implementation of circuits (solder joints, internal wire insulation, capacitors, etc - but not counting the fact that tubes ear out) get "too old"?

My gut says I'm fine (thinking about purchasing a 15yr old tube preamp) but I thought I'd check. Thanks, Travis
I read something the other day about Bryston amps with their famous 20-year transferable warranty. The guy from Bryston was describing the torture test they put each unit through before shipping, and was quoted as saying that they build them to last 50 years, that if properly designed there's no reason a quality amp shouldn't last that long.
Yes, it does. There is a difference between "working" and "sounding like it did when it was new". Generally the passive components like capacitors will age and change value over time. This is why alot of people who buy older equipment have it "re-capped". Anything over 10 years old is a candidate for this, although the severity of this aging may vary with the conditions the equipment was subjected to. High heat is the worst, and Class A amps that generate alot of heat, will "cook" themselves alot sooner than amps that run cool.
my equipment never gets "old". but you ought to see the pictures of them i have in the attic!. Don't laugh, i think its nice to grow old with your favorite equipment - its a nice comfortable relationship, just like the one you would like to have with your partner.
My krell pam3pre was made in 87 I believe....but I still enjoy its phono stage. I bought it second -hand in excellent condition in 98 and will probably use it until it dies. There are some great bargains out there second hand. Just be sure the company is stable and go fo it...
T-Bone: I figure that anything more than 8-10 years old is going to require some refurbishing to sound right (I'm talking tube gear).

I used to have my old Dynaco, Eico and McIntosh gear recapped every 8 years, or so, and my tube guitar amps @ least every 5 years (they always sounded better afterwards).

The only thing is that I am not familar with "modern" caps and resistors as the ones that I used were the same and/or close to the original parts (the last recap that I had done was in the mid 80's).

I need to recap a couple of 40 year old amps (that I have owned for aprrox. one year) and am concerned that modern caps may change the sound too much, though I don't see the point in placing 20 year old (plus) Illinois caps in them (which would sound similar to the originals).

Not much help, am I?
I've heard that the older, paper caps (used in mcintosh for one) can leak over time and need to be replaced.
From my memory of the Last Whole Earth catalog: The flow of energy through a system tends to organize it.

I put a 1970 Dynaco Stereo 120 in the attic that worked fine when I stashed it. Years later, the moment I fired it up it lost a channel. The offending part cost 60 cents. The labor was $60. Over the course of 30 years the only non-abuse, solid state casualty I've experienced in daily use was to a $200 Japanese receiver on KP duty. Ok, I admit I only connected one channel and ran it in mono for a coupla years until it died. But hey, I had just one extra speaker. The clear plastic tuning indicator made a nice staight edge.

Buzzing tubed components require a good whap every now and then to show them who's boss. But seriously, quality high-end products are worth restoring. So no worries. Leave em plugged in!