6cg7 tube: any common equivalent?

[tpatton]

I decided to organize my 9-pin tubes, to make life easier for my heirs down the road someday, and came across some 6CG7's.  I have 6922's in Seductions, and 12AU7's, 12AT7's and 12AX7's in other gear, and I know (?) that 6DJ8's can be used in place of 6922's (at least sometimes), which suggests that the numeral 6 in 6CG7 might possibly not disquality that tube as a replacement for one starting with 12. I have no idea where I got these 6CG7's, other than that they must have come with something I bought.  And I can't imagine what that could be.  Can anyone make a guess on the equivalency question?  Thanks!

[Jim R.]

Hi,

A common equivalent for the 6cg7 is the 6fq7.  Theoretically the 6cg7 as an internal shield between the sides, but that isn't always tre as I've seen 6cg7s both ways and 6fq7s both ways as well.  The 6cg7 is reasonably close to the 12au7 but with different heater wiring, and is also supposed to be the 9-pin mini equivalent of a 6sn7.

I've built my Crack to have a switch that allows me to use  both 6cg7/6fq7 types and 12au7/12bh7 types.

I know some people have converted their Foreplay family preamps to use 6cg7s, but not having one of those I couldn't give you directions on how to do that exactly and if anything but heater pin rewiring is that all that needs to be done.

hope this helps,

Jim

[tpatton]

Jacoby, you seem to have missed this bit of my post: "I have no idea where I got these 6CG7's."  So I can't satisfy your curiosity (or mine).  Jrebman, thanks for all this info--which just makes their origin a greater mystery, since they must have come with some component that uses some of the other tubes I list.  I'll just put them away and not risk even trying them where I now have other familiar 9-pin tube types. 

[mediumjim]

6CG7's are used in Marantz's as driver tubes...

[rock4016]

6CG7 is a 9pin version of the 6SN7, so you may have or had a circuit with a 6SN7 in it.