******* URGENT warning ****** !!!
Oh, FFS..... :doh:
Please tell me, DAFTEE, you've posted the wrong picture of what you've actually bought... IF NOT, and that's exactly what you've bought, then they are THE WRONG VALVES!!.
Look what is says on the boxes in your picture above: 12SK7GTY
Also, look at the construction, compared with the other 6SL7s you're using. It's completely the wrong item. You've bought this (a PENTODE remote cut-off valve):
http://www.r-type.org/pdfs/6sk7.pdf
Instead of this (a TWIN TRIODE):
http://www.williamsonic.com/TubeDI/6SL7GT.pdf
What you probably thought you were buying, was what I recommended earlier, which were these:
http://i665.photobucket.com/albums/v...psgwjtmxo3.jpg
6SU7GTY - a totally different animal....!
Andy, DO NOT ATTEMPT TO PUT 12SK7 VALVES IN YOUR AMP, even if they fit, as if switched on, you might destroy it and/or the speakers connected to it!! :no::nono::nono:
Marco.