Hey all. Just thought I would show this to you in case you got a new one. You might want to check the bias. I got a new Hot Rod Deluxe IV. I love the amp and every channel.
I was putting in Genalax Gold Lion KT66's (match pair) and three Gold Lion 12AX7 (all matched). I was curious what the bias was set at from the factory.
Here is the result:
Plate Current/tube: 34.1 mAmp
Plate Volts: 426 Volts DC
That's only 14.53 watts of plate dispersion (assuming 30 watt max for 6L6's) or 48%--Ideal is supposed to be 70% so factory is really cold.
https://i.imgur.com/DFg7LVU.jpg
So, I put the Genalax KT66's in and plate voltage dropped to 406 volts. Adjusted Plate current to 43.6 mAmps. KT66's max plate dispersion is 25 watts, so 43.6 amps at 406 volts give us a plate dispersion of 17.7 watts or 70.8%.
https://i.imgur.com/w4nGnRT.jpg
I wasn't expecting that much difference in sound because it sounded so good stock, but damn, these Gold Lions are so good. The tone is so good. Such a difference. I can't believe how much of a difference there is. Really warm but crystal clear. And the harmonics are so good.
Anyways, hope this helps someone. Take care!