Re: 12E1 as amplifiers?
Where does it say in the datasheet that they cannot be used for audio? You can use almost any valve for almost any purpose, but it might not work too well.
For a PSU you often need high current at low voltage drop for a series regulator, so low mu triodes (or triode-connected pentodes) are used. The 12E1 appears to have mu=5 when triode-connected. This might be a disadvantage in an audio amp.
The high voltage, high current - but not both at the same time - is again typical of PSU duty (and TV line output stage duty). It gives you flexibility, in that you don't need two separate valves for the two different regimes. If you want both at the same time then you need a much bigger and so more expensve valve.
You can be sure that someone somewhere will have used a 12E1 for an audio amp.
|