You also have know what the filament voltage is as well as the current. The 12AU7 can run on either 12.6V or 6.3V. The 6SN7 is a 6.3V tube. If running off 12.6V in your amp the 6SN7 is not interchangeable.
If the other way around, the 12AU7 can usually be used in place of the 6SN7. We design our Purity Audio preamps to use either tube., but again., they were designed this way.
I would go by what the manufacturer says. They know best what tubes can and cannot be used in their products.
If the other way around, the 12AU7 can usually be used in place of the 6SN7. We design our Purity Audio preamps to use either tube., but again., they were designed this way.
I would go by what the manufacturer says. They know best what tubes can and cannot be used in their products.