The F6CC development continues. I sent a pair of boards to BuzzForb to see what he can do with it.
I am in the tweaking phase, exploring different output FETs, open-loop gains, ... As I said earlier, the PCB design is a "Swiss Army Knife", allowing a variety of options, and lots of tweaking.
I currently am listening at an extreme end with bias=1.3A, gain=3, giving about 26dB feedback, and a damping factor around 20 into 8 ohms. With the pots tweaked to minimize the harmonics, it sounds more like an F5 (neutral) than an F6. But with less feedback or less bias current the harmonics increase, and of course output FET source degeneration can be increased, and push-pull gain factors can be changed to modify H2.
I am in the tweaking phase, exploring different output FETs, open-loop gains, ... As I said earlier, the PCB design is a "Swiss Army Knife", allowing a variety of options, and lots of tweaking.
I currently am listening at an extreme end with bias=1.3A, gain=3, giving about 26dB feedback, and a damping factor around 20 into 8 ohms. With the pots tweaked to minimize the harmonics, it sounds more like an F5 (neutral) than an F6. But with less feedback or less bias current the harmonics increase, and of course output FET source degeneration can be increased, and push-pull gain factors can be changed to modify H2.
the one's ive tested don't do much for me (well so far) ... gain of the cree part especially is just too darned low to be of much use in common source mode.
Buzz I get where you're coming from but imho, the reality is that for pratical purposes, they are inextricably linked. I'll post the curves over the weekend
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I saw them in the other thread. I believe the newer Cree have slightly higher gain. Rush has some, as do I, but i haev not even taken them out of the bag.
Still available at acorn man n yes, I do believe that he Could....
