I tried almost every make and model, (and equivalents) when I had my SWL9.0SE Sig and found that I liked the Amperex Holland 7119 the best. I also liked the Raytheon Red/Orange label 5687. The Tungsols were very good also.
Make sure you use a Mullard (Great Britian) 5AR4 as the rectifier tube.
Make sure you use a Mullard (Great Britian) 5AR4 as the rectifier tube.