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
They sound fan-f*ing-tastic. Wow. I'm going to save up for a NOS pair or two. Wow, wow, wow....
Borders on a musical epiphany, does it not? As Trelja noted: The built quality back then was much better than that exhibited in today's manufacturing. Try to locate either TungSol or Sylvania 6CS7 dual triodes, for the preamp section(must be closely matched pairs and low noise). Small signal tubes have a major effect on presentation. Many don't realize how much can be gained with a NOS tube in the power supply. Replace that 6CJ3 rectifier for even more musical enjoyment. Welcome to the wonderful world of tube rolling. Happy listening!! =8^)
Yes. Yes. Yes.
I've removed the tubes from the amp and encased them in 20 layers of silk velvet. I'm thinking I will only put them in for special occasions. Why waste them on the kids when they are listening to Dan Zanes! No disrespect to the very talented Mr. Zanes intended.
I guess I should just find a NOS quad.
I just ordered some Sylvania 6CS7's today. What about RCA 6CS7's? Do you know of a source for Tung Sol 6CS7's? Really, the rectifier will make that much difference?
Finding TungSols in matched pairs will be hard to do(no- I can't cite a good source), but worth the effort if you can locate some that are low enough noise for a preamp section. Depending on what half wave rectifier you are presently using(ie: Chinese), you should have an audible improvement by installing say, a NOS RCA. They're selling for around $5 now, so the experiment will be cheap. Too bad there aren't any Mullards out there.
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