[smwick]

I have a two year old Fet Valve Ultra II 350 amp with a lot of hours on it, and think it might be time to change out the 12AT7A tubes.  I know Frank's tubes are quality tubes, but are there any other quality choices?  I saw a couple people recommend Gold Lion tubes.  Also, what is the difference between a 12AT7A tube and a 12AT7 tube  ?  Thanks.

[NIGHTFALL1970]

I recommend the cryoed Genalex Gold lion from www.cryoset.com.  However you need a matched pair and they have been out of them for months.  I have been trying to get some extras lately. As to your question bout the "A" I don't know.  Give Frank a call and tell us what he says.

[JerryM]

Also, what is the difference between a 12AT7A tube and a 12AT7 tube  ?  Thanks.

The "A" designation typically denotes "low noise". 

Have fun,

Jerry

[mark funk]

I run Telefunken ECC81 in my Fet Valve Ultra+ 550 it sounds OK to me.