Base 7S or 7AC - Printable Version

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Base 7S or 7AC - Phlogiston - 11-03-2017

Can anybody tell me the difference between the 7AC base (6L6) and the 7S (8417) base? Look the same to me.
 
I wanted to try some tube rolling on my new project and can't see why they speced the bases different.

Blog/story to follow - Super MP3 adaptor -

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RE: Base 7S or &AC - Ron Ramirez - 11-03-2017

Agree, 7S and 7AC look the same to me as well.

Only, tube type 8417 is listed as having an 8LY base on my favorite online tube database, NJ7P.org?

Edit: Duncan Amps shows 8417 as having the same pinout as 6L6. I'm not familiar with the 8LY designation.

Edit #2: RCA tube manual RC-30 shows the 8LY designation as having pins 1 and 3 tied together (plate). Otherwise the same.

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RE: Base 7S or &AC - Phlogiston - 11-03-2017

Ok. I see that now on RM. My 1966 RCA tube manual (25) does not list the 8417, so I got the base off of another site. I guess that site is wrong. Still I wonder why 7S and 7AC are drawn the same - and we might never know.

So I don't think that I'll try that tube.

Thanks

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