Link555
18 June 2010
I have never used a 12BH7 before.
Two questions:
1) In Urei LA2 they use a 12BH7 in the output drive section instead of 12AX7(more gain I know) or 12AU7, why is that?
2) Other that the heater current, what is the difference between a 12AU7 and 12BH7?
Thanks!
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I am not sure if I am mis reading the data sheets, but its appea
I am not sure if I am mis reading the data sheets, but its appears that the 12au7 mu is 17
and the amplification factor of the 12BH7 is 16.5
They are pretty simular
?
[="http://thetubestore.com/jjecc802sg.html"]JJ ECC802-S / 12AU7 Gold[/]="http://thetubestore…"]JJ ECC802-S / 12AU7 Gold[/]
[[url=http://="http://www.eierc.co…"]12BH7[/]="http://www.eierc.co…"]12BH7[/]
I've never used a 12BH7 either, but [="http://www.diyaudio.com/f
I've never used a 12BH7 either, but [="http://www.diyaudio.com/forums/tubes-valves/9862-12au7-vs-12bh7-vs-6cg7.html"]here[/]="http://www.diyaudio…"]here[/] is a semi-sensible discussion of it, including substitution for a 12AU7.
The [[url=http://="http://www.r-type.o…"]data sheet[/]="http://www.r-type.o…"]data sheet[/] shows it targeted at TV frame circuits, and it looks at first glance to be a low-mu device capable of handling higher currents than a 12AU7. That may mean it is more suitable for driving output transformers (secondary loaded with 600 Ohm), and so could be why Urei specified it in the LA2.