-=> Quoting John Allen to All <=-
 JA> As an absolute newbie to the world of tubes I am looking at
I started last year with the purchase of a Golden Tube Audio
SE40 amp...
 JA> an S.G.JoLida Integrated amp/pre-amp advertised in Audio Advisor. It is
 JA> 1. How long should you expect to get out of a set of tubes?
I think 2 years for power tubes and 5 years for input/driver
tubes is pretty normal.  But one of the fun parts of owning
tubes is that swapping out to different tubes can have drastic
effects to the sound.  Upgrading 2 tubes on my amp for < $40
made a HUGE difference in sound.  
 JA> 2. How long should a tube unit be allowed to "warm up"
 JA> before playing?
They will play from the start, but sound better after awhile
(30 minutes in my case).  
 JA> 3. Do the "tube covers" (look like little tube sweaters)
 JA> actually increase tube life?
No idea.  But I might poll the Golden-Tube-List for this...
 JA> 4. What things are tube amps/pre-amps sensitive to/about
 JA> that might cause them NOT to play at their optimum?
The biggest on my GTA is biasing the tubes properly every
3 or 4 months.  Tube amps are higher maintenance than tube
pre-amps, Also, in single-ended amps, I think the speakers
need a flat, consistent impedence curve.  
 JA> 5. Are tube units more or less sensitive to vibration and
 JA> should extraordinary effort be put into their isolation?
Having wondered the very same and never getting any real
evidence either way, I have found out most GTA owners do some
sort of spiked racks.
 JA> 6. Can a tube amp like I described be placed in an enclosed
 JA> (no back) entertainment center without overheating etc
 JA> or - - must they be in the open air due to heat? (I have
 JA> often seen them called "space heaters").
Normally I'd say no.  The amps do throw off lots of heat.  My
rack has 13" shelf spacing for this very reason.
 JA> 7. Am I nuts for even considering getting into tubes?
Absolutely not.  Tubes are making a comeback big-time, and
Jolida, Golden Tube Audio and Anthem are making it affordable
for the non-soldiering gun weilding crowd.  Anthem (by Sonic
Frontiers) makes a nice little integrated, but its over $1k.
As long as you buy off on the higher-maintenance of tubes and
the limits on the speakers (especially with low powered single-
ended amps), I say go for it.  My GTA amp is probably the least
expensive piece in my system, but I consider it the biggest
"feature".
 JA> I would also appreciate thoughts and suggestions on the
 JA> S.G.JoLida integrated amp mentioned above. The smallest of the three
 JA> amps got some good ink in Stereophile recently, but that does not
 JA> substitute for real people  experience.
Let us know how it turns out.  I'd LOVE to get one of those
little heaters for the bedroom system, but can't really justify
it right now.
--- Blue Wave/386 v2.20 [NR]
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