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12E1 tubes (help)

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Looking at the data sheet, you are going to be limited by the Vg2(max) restriction of 300V. Other than that, the valve looks as though driver circuits intended for EL34 or KT66 might be good, so the Williamson driver is an obvious possibility. Your problem is that even if you only have a 300V HT (which will restrict output power), there is a possibility that the 12E1 will object to swinging Vg2 > 300V on audio peaks. Of course, if you have lots of 12E1, you might be willing to sacrifice a pair to science.
 
12e1

EC8010 said:
Looking at the data sheet, you are going to be limited by the Vg2(max) restriction of 300V. Other than that, the valve looks as though driver circuits intended for EL34 or KT66 might be good, so the Williamson driver is an obvious possibility. Your problem is that even if you only have a 300V HT (which will restrict output power), there is a possibility that the 12E1 will object to swinging Vg2 > 300V on audio peaks. Of course, if you have lots of 12E1, you might be willing to sacrifice a pair to science.

12e1 have mu of about 5 as triodes making them slightly more 'difficult' to drive than EL34 , KT66 etc . I built a trioded 12E1 amp a few years ago based on the Williamson circuit but using triode-strapped A2134 as drivers . 6SN7 as a driver sounded rather flat , something more substantial is required . Sounded very nice , I ran the things at about 330V 75mA 6k a-a load , good for about 13 watts . No problem running at 400V either but the curves start to flatten out at about 350V . An excellent valve for the money as long as you can put up with topcaps !

316a
 
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Joined 2003
No gain without pain...

You could undoubtedly obtain more power using 12E1 as pentodes, and you could improve performance by regulating Vg2 and adding local feedback. Alternatively, you could stick with triode-strapping, but accept that this shifts the problems to the driver, as 316a pointed out. It's down to how much you are prepared to experiment, and what you are prepared to sacrifice.
 
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