I am considering going to a tube amp, after 25 years
of solid state amps. (Specifically, it is a conrad-johnson,
but my question is general.) I have read comments
through the years about the problems tube amps
have ("always in the shop", etc.). Is this a reality?

Conrad-Johnson has been in business for more
than 20 years. They haven?t survived, with a good
reputation, because they produced faulty products.


I live in a town with no tube amp dealers, and would
need to send it back to the manufacturer if it fails. Are
my knees quaking for no good reason?

Certainly power tubes will be limited to less than
2,000 hrs. For most people that?s several years of
use. Some amps require periodic manual biasing
of the tubes for longest life. This requires the use of
a handheld meter to reset. Others are auto-biasing.
The price to re-tube a power amp can put some
people off. Re-tubing of 6550/KT88/KT90/KT100, for
example, can be expensive. The cost can range from
$25 to $100 per tube.


If an amplifier is properly designed, in a continuous-use, stationary
setting a GOOD push pull pair of power tubes can last a LOT longer
than 2,000 hours.
Many of the old small urban AM stations used a pair of 845s as
modulators and they always lasted at least a year or two -a year being
365x24=8760 hours last time I checked. Early Gates/Harris BC-1s used a
pair of 807s-usuallly the same cathode structure as a 6L6-as drivers
for the 833 modulators and finals and again the minimum life was a
full year.

See Rich Modafferi's article in AudioXPress for more information.

As far as conrad-johnson goes, they are not "poorly constructed" or
"bad" but personally I disagree with their biasing mechanism and I
think they're way overpriced. But that's just an opinion-if you like
them and feel they are good value then good for you. I think BMWs are
overpriced and hard to work on for owner/maintainers-BMW owners
obviously agree with BMW pricing and have all work done by the dealer
or snooty German car shops, so that for them isn't an issue.

As far as conrad-johnson goes, they are not "poorly constructed" or
"bad" but personally I disagree with their biasing mechanism and I
think they're way overpriced. But that's just an opinion-if you like
them and feel they are good value then good for you. I think BMWs are
overpriced and hard to work on for owner/maintainers-BMW owners
obviously agree with BMW pricing and have all work done by the dealer
or snooty German car shops, so that for them isn't an issue.

I'm not sure who would ever say CJ was "poorly constructed" - and I
can't comment on biasing other than they are the easiest that I've had
experience with to bias. As for overpriced, they are not cheap, nor do
they price up into the stratosphere, especially considering the parts
list and quality of the chassis. Also, they maintain their value on
the used market which makes them a good investment if you want to try
different pieces over time.

I would modify the above point to say I think all cars that cost
$50,000 and up are "overpriced"... as I think any amp or preamp that
costs $10,000 (or more) is silly.

Incidentally, you will never see me to buying a CJ-ART preamp for
16G... but I might spend ten on a nice used system and take the family
out for a great vacation somewhere nice (anywhere) for 2 weeks, but I
would certainly vouch for CJ gear if it fits your listening tastes.

J-