I decided to put the pentode back into Kenwood 1100U, but I didn't want to put in a 6AN8. So I wired it for a 6GH8/6U8/6BL8. I've never made an amp with a pentode front end, only worked on them. I've got lots of gain, and a buzz. The buzz comes on with about 20 volts PP at the speaker terminals with a 6BL8(pictured). With a 6GH8 or 6U8 I'm getting it at the bottom at about 30 volts PP.
Here's the schematic, except the 6AN8 is no more: