I had the Sira in my system for a short time but I did do some tube rolling for the input tube. Aside from a Tung Sol 5687, I tried Bendix 6900 and RCA 7044 tubes. The 7044 is a nice sounding tube, but many were noisy.
In my Epifania I'm using a Brimar 5R4GY/CV717 rectifier and I really like it. I also have used RCA 5R4G, TJ meshplate 274, and the Phillips Holland 5R4GY tubes. I didn't try different rectifiers in the Sira.
In my Epifania I'm using a Brimar 5R4GY/CV717 rectifier and I really like it. I also have used RCA 5R4G, TJ meshplate 274, and the Phillips Holland 5R4GY tubes. I didn't try different rectifiers in the Sira.