When I first built my F6 I ran the bias at 800mA with a 27 volt supply then had it set for a few weeks at 1200mA and found it a bit thin and lacking in the punch.
I then raised it to 1.6A which is where it has been for the last 9 months and it sounds just perfect sound stage wide and plenty of low down oomph. Maybe it is because I'm using the SiC Fets which have lower transconcutance than the IRF's?
(Will be doing the positive feedback mod this weekend just to see.)
I then raised it to 1.6A which is where it has been for the last 9 months and it sounds just perfect sound stage wide and plenty of low down oomph. Maybe it is because I'm using the SiC Fets which have lower transconcutance than the IRF's?
(Will be doing the positive feedback mod this weekend just to see.)
Try it like this on one channel and let me know how it sounds. You'll need to rewire it slightly. M1 has no degeneration, and M2 has a small amount of degeneration.
2nd harmonic model. My sim at .65 vin is -52db 2nd and -73db 3rd.
sim with normal degeneration connection is -60 and -73.I'm curious as to how it sounds,maybe my nirvana.Thanks for the info.
Probably does. When you set the bias to a different point, you would normally
also adjust the pots which govern the distortion harmonic spectrum.
The original design was set at at a fixed 2nd harmonic at 1 watt. If you want
apples to apples comparison on bias, you might want to look at that.
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