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Little 12BY7 S.E.P. Amp
http://diyaudioprojects.com/Forum/viewtopic.php?f=9&t=3751
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Author:  Geek [ 01 Mar 2017, 06:09 ]
Post subject:  Re: Little 12BY7 S.E.P. Amp

tizman wrote:
I played around with the pentode curves to see what a 5K load OPT looks like and it doesn't look great.


When paralelling, you use the curves for one tube at load (8K in this case), then reciprocal for the amount of tubes. So, a single SEP = 1/1 = 8K. Parallel class-A tubes (pentode, triode, whatever-ode) = 1/2 = 4K. Three tubes = 1/3 = 2.66K, etc.

tizman wrote:
Would a anyone happen to have triode curves for this tube?


Trioding these will give you pretty much the power of parallel section ECC88. Then do Bruce's headphone amp for better results ;)

Cheers!

Author:  tizman [ 01 Mar 2017, 13:13 ]
Post subject:  Re: Little 12BY7 S.E.P. Amp

Thanks Gregg. Parallel pentodes it is! I'm glad that this finally motivated me to do some pentode load lines. Here are a few pictures of the tubes. This is about two thirds of them, there is another container of loose ones somewhere and a dozen or so in boxes. I don't think I have as many as I thought though. More close to 90 in total. Mixed in with the 12BY7A bag was 30 12GN7a that I separated. Are these useful?

Author:  Geek [ 01 Mar 2017, 14:21 ]
Post subject:  Re: Little 12BY7 S.E.P. Amp

That would make a Citation owner drool :D

Author:  tizman [ 01 Mar 2017, 17:30 ]
Post subject:  Re: Little 12BY7 S.E.P. Amp

I'm always drooling over things I don't have. The last photo is a bunch of 12GN7As. Are they good for anything? Since I have a bunch :thumbsup:

Author:  Geek [ 02 Mar 2017, 00:01 ]
Post subject:  Re: Little 12BY7 S.E.P. Amp

36,000uMhos? Holy crap! That'd be a great spud amp :D
Look at those transfer curves. Dang! I'd say yes.

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