12AH7A info

[Howlin' Mad Mac]

Was pulling parts from an old Hammond H-143 organ this past week... got a lot of nice vintage goodies from it, among them a 12AH7A tube. Having not previously come across this particular variant of 12A_7 tube before I went about looking up a datasheet for such an animal when things went awry. I was able to find data for a 12AH7 (no A suffix) & a variant, 12AH7GT, both listed as being a dual-triode octal tubes however the one I'm grasping in my fingers has 9 pins. Anybody know anything about these guys? I'm going to guess it's a low mu tube like a 12AU7 (aka almost worthless) but still curious.

[Diablo]

You sure the tube you're looking at isn't a 12BH7A, with some smudged B that looks like an A?

[Rhodesplyr]

I'm a Hammond tech. Yes, it should be a 12BH7. If you don't want it, send it to me :-) They are very similar to 12AU7s, but with twice the heater current draw larger plates.

[Howlin' Mad Mac]

Thanks guys... Actually showed the tube to a friend over the weekend. After his first glance he scratched his head a bit as it does in fact look like it's stamped "12AH7A" then looked again real close... turns out it's stamped "12AU7A" then over-printed "Hammond" in orange so that part of the overprint makes the "U" in fact look like an "H". Doh! Anyway, mystery solved lol!

[Howlin' Mad Mac]

Hey Rhodesplyr... turns out this tube IS a 12AU7A but I do have some 12BH7 about too as I've got Hammonds coming out of my ears (presently I've an A-100, A-102, L-102, T-??? & an M3 in my collection) plus lots of various parts from many others I've scavenged. Been wondering most about the massive power tranny out of the H... guessing that baby has to be worth something to someone somewhere. New ones, if even available have to sell for several hundred I'd imagine. If ya know of anyone that could use a hunk of iron like that tell 'em to shoot me an offer, cash or trade.