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PostPosted: Sun Aug 25, 2013 11:49 am
by verdi29
Have a pair of Avvt 302B.

Need to start using them.
Since being older tubes they need to being treated gently with great care.

What is the best or good way to get them ready for my amp.

Re: AVVT 302B

PostPosted: Tue Aug 27, 2013 7:50 pm
by Jac
Hello, and welcome on the forum.

Are you sure the tubes have been sleeping ever since??
If they have been used in between, there is nothing special to do.

If yes, here are the instructions, just scroll down.
For better navigation you should go there via the jacmusic site.

AVVT 302B is a very good tube. It draws very much heater current,
so make your you have the 5V as required. Some people underheat
them unknowing.

This is not a 300B. It biases like a 300B, but heater current is 2x higher,
and so is peak emission. Be careful, you need a relatively low grid
resistor like 50k.


Re: AVVT 302B

PostPosted: Sat Aug 31, 2013 8:59 am
by verdi29
Thank you Jac.
This is the information I need.

Yes they have been sleeping but have been burned only at the factory as far as i can see.

The whole tube is clear and only where the getter is near the glass there is discolour from higher temperature.
I am open for offers as well.

Re: AVVT 302B

PostPosted: Sat Aug 31, 2013 5:44 pm
by Jac
Hello Verdi,

with AVVT there is normally no conclusion possible from getter appearance. These getters are of a kind that maintain the vacuum witout appearance changes, as long as there is no grid current. Any colorings, spots, stains or whatever, it's normally the way they were born.