. . . "ck and probably adjust the neutralization on a tube change anyway. so if the tubes are soft, just try it. most of the NOS is 6146 B and W tubes.for that matter, there was a lot of talk about upgrading to the tougher 8298A. well, he is the 6146B, they are dual-branded.if it runs wild, well, you have other parts bad or perhaps do not have enough range in the neutralizing cap. troubleshoot or put in t" .