Hi there, I have spend quite some time with varying schemes. In the end I ended up using silicon rubber O-Rings and Steve's "Shim Mick" Wooden disks. http://www.enjoythemusic.com/tweaks/ (Scroll down slightly on the page untill you see wood.) Non of these have yet ruined my valves (and I like rare, more or less excotic and expensive stuff). A friend of mine uses the Rings on the WE417A Valves in his Preamp, run close to the max dissipation (4 Watt in a half height 9-pin package). I myself tend to use the Rubber Rings on really microphonic Valves (like in the MC Phono-Input). On less effected valves (in my Line-Stage - Mullard E88CC and in the Poweramp - WE417A and Svetlana 300B) I use the "Shim Mick" Disks. I have drilled small holes into them and added Copper Wire (1mm) in a style like the Shun Mook Valve Resonators. It keeps the disks from falling off and seems to further reduce Microphonics. http://www.shunmook.com/text2.htm The wooden disks also seem to open up the soundstage. Again, even on 300B's near the max dissipation, the wooden disks have survived without burning up, though their contact-surfaces to the Valves has become darkened. I have used both products for over a year now and would not miss them in my system. And considering the Price.... ;-) As for metal around the valves, I agree with Steve. I believe the reason is the induction of eddy currents. The slight loss of Detail and transparency when using metal shileds on Valves is similar to the one experiences if an Interconnect has a shield closely spaced to the conductor.... Of course, I might just be hearing things here (I definitly do BTW - mostly music of course).... Later Thorsten
|