Toying with the idea of juicing one of my hybrid heads, (tube preamp w/SState power amps), in order to gain more headroom. One thing I know I can do safely is make sure I'm using 14 gauge speaker cable. But do you think any of the following, (which I would have done by a pro), would be worth the trouble/expense? Other headroom ideas ? Thanks in advance for any input. > In the solidstate rectifier circuit, change the existing diodes to a higher amperage rating, such as the IN5408? > Replace the existing 12AX7 with a 12AY7 or a 12AT7? > Double the value of the filter capacitor that feeds the screen resistors, (not the preamp)?