[Amps] 811s for 30L-1

[Steve Thompson]

I'm sure this has been covered in the past, so please excuse me for asking 
again and not trawling the achives.

A friend wants to buy in some spare tubes for his 30L-1. Readily available 
brands seem to be Taylor, Svetlana, Marshall and Cetron - are any of these 
particularly good, or especially worth avoiding?

If it's relevant, the 30L-1 is designed for tubes with a shouldered envelope, 
and the tubes sit horizontally.

Thanks,

Steve