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Do the tubes have to be matched?

I have a pair of ASL wave-8 mono blocks. Each one takes a pair of 6bm8 tubes. Right now i use 2 sets of matched Svetlana. I can get some nos Sylvania from a local electric supply house. But they have no way to match them or even test them to see if they work. At $28.00 each i wonder if it's worth it to get them. I have found there aren't that many choices of this style tube available even on the web. By the way these amps are auto bias. Thanks for your help.

Tommy
tommy583
racamuti's avatar
racamuti
362 posts
 
If you really want those tubes, you can buy them and send them to a tube retailer and have them tested and matched for a small fee. The code seems to indicate that they were made by Mullard at their Blackburn plant. Andy at Vintage Tube Services or Charlie at Vacuum Tube Valley can perform the tests and tell you if they are microphonic or not.
cyclonicman
693 posts
 
You may want to consult with Kevin at www.upscaleaudio.com. He only sells quality tubes and will offer good advice, plus he has the ability to test tubes. They also have Nos Japanese 6bm8 tubes in stock at $20 each.
tommy583 OP
73 posts
 
It would be nice if i could buy the nos Sylvania's then send them out for testing. But i doubt i could return them if they didn't test well. At that point i think i would be s.o.l. Bye the way since these are push pull amps do the tubes have to be matched?

Tommy
racamuti's avatar
racamuti
362 posts
 
The tubes should be matched. That what the people we recommended would do. Since they are output tubes micrphonics might not matter as much. I bought a bunch of sv83 tubes off of ebay and sent them out to be matched after receiving them.
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