Jim Lesurf wrote:


I also wonder if *all* buyers of valve power amps knowingly do so on
the basis that the output values are 'consumables' and might need
replacing in as little as just over 90 days.


** That is not what the 90 day limit really means !!

Which doesn't establish that all UK buyers know about this.


** Which is an utter, pedantic irrelevance.


Warranties on consumer items do not cover fair wear and tear, the
effects of unusual and harsh usage or commercial use.

As above, I don't know of a UK court case that agreed this *is* "fair wear
and tear of a consumable" if the valves failed in just over 90 days.

** You are sounding like a stuck record and you need to learn to read ahead too.

A 90 day old valve amplifier might have had 24/7 operation and clocked
up 2160 hours.

Or might not.

** More pedantic, irrelevant and absurdly argumentative crap.


In the absence of a reliable measurement ...

** Obviously, you have had very little to do with valves.


There is nothing straight forward about the situation

I agree, that's what makes me raise wonder about the above.


** You clearly did not even read or comprehend what I wrote.

The 90 day period establishes a threshold to distinguish valves that likely had a built in factory fault and ones that have simply worn out by being subjected to continuous use.

Worn output valves have low cathode emission and many visible signs of the long term effects of heat.

OTOH a valve that has failed early due to a factory fault will likely look perfect and yet not function at all, because the heater is open or the vacuum lost.

A big problem is that valves are *user replaceable* and not a permanent part of a particular amplifier, owners can do what they like with them, swapping them about and hence causing havoc. Such owners have no right to claim on a warranty.

The TRUTH is valve amps are an *anachronism* that still exists only because people *want* to use them, not because they are good value or reliable pieces of electronics.

FYI:

I have been continuously dealing with good and faulty valves, both new from the box and long in service for nearly 50 years.



.... Phil