[jcmusic]

I am trying to find a good sub for this tube in my phono stage, anyone here know of any drop in replacements? The problem I am having is the 12AT7 has a little too much gain and is noisy, I tried a 12AU7 not enough gain. So something in the middle, I have read that a 12AV7, or 12AY7 may work???

Jay

[doctorcilantro]

How many does it take?

[silver_strings]

12a tubes are usually always interchangeable a 12ax7 should work well, but sometimes amps are built for the specific tube so it might not work well if you try a different 12a tube , try contacting the manufacturer if you can

[Pez]

No way, 12ax7 has a gain factor of 100, WAY more than the 12at7 which is 60. You might want to try something more like a 12ay7 or 12av7. Maybe also try another type all together like a 7062 which is close to equivalent to 12at7, though in my experience they can cause more noise issues so who knows. Also check here for a decent cross reference chart:

http://www.diyguitarist.com/GuitarAmps/SD-Convertible/patgf1.htm

[naggots]

You could check audiotubes.com for a list and/or ask tubemonger for advise