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I use a somewhat uncommon power supply configuration for fixed bias output tubes. Here is an example: http://users.adelphia.net/~thomasholley/Bass Power Supply.gif . I used this in a Bass Guitar amp with four 6550 output tubes. The power transformer was a Hammond 278CX with additional filiment supplies.
The uncommon part is the way the negative voltage is derived from the center tap. Admittedly, I overdid the wattage here, but you do generate some significant heat. It also takes some generous capacitance to adequately smooth the bias supply.
The benefit I see in this configuration is the way the power supply sag interacts between the B+ and bias. It renders a very good result in both musical instrument amplifiers and Hi-Fi amplifiers using fixed bias. When using this configuration I always get a very pleasing sonic quality to the amp so I use it exclusively on fixed bias arrangements.
The uncommon part is the way the negative voltage is derived from the center tap. Admittedly, I overdid the wattage here, but you do generate some significant heat. It also takes some generous capacitance to adequately smooth the bias supply.
The benefit I see in this configuration is the way the power supply sag interacts between the B+ and bias. It renders a very good result in both musical instrument amplifiers and Hi-Fi amplifiers using fixed bias. When using this configuration I always get a very pleasing sonic quality to the amp so I use it exclusively on fixed bias arrangements.