Check with Aki at TubesForAmps.com. I've bought a lot of 6550 tubes from him over the years. In fact, I need to get a few more right now. So we'll make a run on 'em together.
I sent off an email this weekend, Wayne. I am also thinking of contacting a
"pro music audio forum:, that deals/discusses guitar amps, recordings, that kind of thing.
The tubes would be ok when watching a movie and comparison purposes, and to save my good tubes.
I see where one site raised the price of output tubes ~43%.