[NX211]

On Aug 17, 7:38*pm, Patrick Turner wrote:
On Aug 18, 8:17*am, NX211 wrote:



On Aug 16, 10:37*am, charles rollo charles.rollo.

wrote:
Recently my amps trannies were melted when the 211 failed. With less
than 150 hours on the tube but past the 30 day warrantee.
I bought the tubes in Oct. 2009 from Grant Fidelity. however never
used them until well after the 30 day time frame. Which Grant was aware
of.
One tube shorted and took out the output and high voltage trannies.
Costing me $1500 to repair.
Neither Grant Fidelity nor Full Music will care after the 30 days
expires. For $500 one would think that the Manf. or north American
distributor would make ammends because of the damage done. Something
fishy going on as the distributor.
No no and no is the answer from them. Buyer beware. Stay away.

charles

--
charles rollo

I had a new KT90 arc in the base from the plate to the filament and
literally melt down with only 50 hrs on the tube. How do you explain
that to the guy you bought the tubes from. *Not too cool.

I bought about 20 KT90s from New Sensor some years ago and fitted 8 to
a 8585 stereo amp which has B+ at 480Vdc.
Not one has failed early. *But KT90 made in the old EI yugoslavia
factory were very prone to malfunction and failure if they become red
hot due to a speake cable short.

Also had a new KT120 with about 75 hrs on it fail from a bad
connection on one of the filament pins. Then again, bought some JJ
KT77's with something floating around in one of them and it arced
internally with a big flash when installed. *I knew I should have
immediately sent it back before installing it but I didn't - and I got
burned. * These aren't operational problems with the amp but poor
quality control from tube manufactures.

New Sensor test most tubes during the grading and matching process and
they don't rely on the makers in Russia to do it. Maybe New Sensor
discard 5% of the tubes sent to them from the factory. The number of
failures is not publicised for obvious reasons lest it create the
opinion that tubes are all dodgy and you are lucky to get any which
work properly.

But Quality Control during tube production ALWAYS was a problem in
itself because HUMANS are much involved doing repetitious work. And
its mainly womens work. Anyway, if you worked in a tube factory you'd
know just how easy it is for **** to happen.

I have had bad soldering of wires to tube bas pins and its easily
fixed by re-soldering. In all my amps there is active protection and
the amp just cannot remain turned on if any single output tube
malfunctions in a manner which leads to excessive cathode currents.

Also bought some cheap Chinese 6L6GC's with hundreds of hrs on them
now and the perform flawlessly. *You don't necessarily get what you
pay for when it comes to vacuum tubes.- Hide quoted text -

If you get 95% of what you pay for then this is good because if all
tube production was being done in the USA or Oz or UK like it once
used to be done then you'd be paying +20dB more for the tubes because
of the much higher cost of labour and compliance with workplace safety
regulations.

I cannot understand someone buying an expensive KT120 when 2 6L6GC can
give similar power. But in Guitar amp land there are those who will
buy anything offered.

Patrick Turner



- Show quoted text -

Ah - KT120's are neat tubes. They'll work in most amps that use
KT88's, etc. and you'll run out of power supply way before you run out
of tube. $100.00 and they'll last for years if you get a good pair.
Put 600 or 700 volts on them and they'll rock your neighborhood.