It has no tuning section, hence it's not a reciver. It also runs 6BQ5/EL84 tubes in the output stage -- What you prob. have are trannies from an x100-b or c - or other - slightly later integrated amp and they, i'm nearly certain, run quads of 7591s (many, many Fisher, Scott, Sherwood, etc. run 7591's).Re: Al, he's a busy guy and while a nice fella, i wouldn't hold my breath waiting for a response -- if i were you, go to the vintage section of audio asylum and keep an eye out or ping jimmydee or smglaw (two very knowledgable Fisher guys) and see if you turn up anything.