It is about that time of year when I buy power tubes. I'm currently running some 6L6GCs as an experiment. A Chinese tube experiment that is. I've run them for about 6 months with little or no problem and they sound great. However, I think it might be time to get back to the NOS or Russian tubes. I'm thinking about the Tung-Sol 7581A. I hear they are interchangable with the 6L6GC and I assume they'd bias at about 0.40/0.45VDC. Has anyone used the 7581, from any manufacturer in their VTA-70 gear? They are supposed to provide more headroom apparently.
Any opinions would be welcome. Even smart alec ones.