Used tubes question


I bought a used quad of xf2's. They were cheap, 150.00 bucks, so I figured I'd give this older-mullard-tube-thing one reads about so much a listen. Now I worry about putting them in my intergrated. I have a Leben CS-600 and fear it going up in flames. The seller said they were closely matched and tested on his such and such tester. He had plenty of positive feedback. Should I just pop 'em in and see what happens? What is the worst that can happen?
128x128oldsalt
I only use NOS tubes and there are big differences between these even in the Mullard variety. I switched from Phillips miniwatt 6GW8 for my Rogers Cadet III to English Mullard NOS. I am finding these harder to source but I hunt them down. Massive improvement. Good NOS rectifiers will improve things further. Lebens are respectable little amps and contrary to common misconceptions quite robust. The only thing is the Leben fixed or cathode bias if the latter pop em in and enjoy. Cheers
Wow again. What a difference with the Sylvania 6CS7's. It is more dramatic then when I added the xf2's. BTW-The CS-600 is more than respectable and more than little :-).
Those that don't experiment with NOS tubes, just don't know what they're missing. Enjoy your music!! =8^)