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.


It's imperative tubes are tested -- . End of subject. As far as your 6BM8 goes -- how about the European equivalent ECL82?
Do a Google Search for Jim McShane tubes and he will be one of the best sources to deal with and he is recognized as one of the best in this business. He has excellent knowledge of a lot of gear out there and he has kept me
happy with all my tube gear for sometime now.
He will help end the madness that you are going through. There are other reputable dealers out there but none give you the warranty and service that Jim offers. You will smile with the service you get and the quality as well. And he has some NOS tubes too.
Thanks for the tip. I emailed him this morning. His site was helpful and so were the links off it.
The tubes i was talking about above were in black and yellow Sylvania boxes that have a made in England stamp on them. The tube itself says Sylvania made in england, tested in USA. With codes KBV ef, OG2 B9B3 also on them. The guy at the store said they were made by Mullard.
I've never seen these one's on the net. I was thinking maybe i'd found some real rare nos tubes, but like Ontjesr said they guy can't test them let alone match them. If i could find someone with a tube tester around here that could help.
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.
You may want to consult with Kevin at 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.
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?

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.