Tue, 17 Dec 1996 19:50:31
To:   Andrea Ciuffoli 
From: kevin kennedy 
Subject: Re: OTL first tests

>Buon Natale e tante auguri per il nuovo anno anche a te.
>Just a question before Natale:
>Is true that the lifetime of 6C33C-B is 700 hours only; a shop in
>Rome yesterday told me that He have received a fax with this
>I have 4 tubes now !! and it is a very short lifetime !!
>thank you, buy buy
Hi Andrea,
The service life I heard was 1000 thousand hours in a high G, high
acceleration environment (jet fighter) for the B type.  In domestic use
these should easily last a few thousand hours, particularly if they are
operated conservatively at 75% or less of nominal rating.  Ralph Karsten at
atmosphere told me that he had some that lasted over 10000 hours if memory
serves me.  
Ciao,  Kevin
Check out my website at http://www.ultranet.com/~kennedyk for articles,
and design information relating to tube hi-fi.