Re: 6L6s in a Vintage Modern?
6L6 tubes will fit and can be used, however the amp will need to be rebiased. The 6L6 will be a darker tube with perhaps more bottom end but IMO they are not doing you any favors. The KT66 is a great tube and the correct tube for a VM. If you like the tubes then thats all that matters, I think you should at least try the KT66 tubes, I think you would be even more impressed.