First Watt SIT5

By actual measurement the AC current through the Mosfet is about 20% of the output current.

I've always wondered about this.... saying that one is 20% and the other 80%...

Do they both affect the "sound" the same way?

I mean, is just a little bit of SIT affect the sound more than the MOSFET? Say, just 10%, or are we looking at a linear effect?

Not taking into account stuff like power and speaker efficiency and so on....

Did anyone think about installing a knob in the SIT5 like the SIT1? In this case to affect the balance, say from 10 to 30%, of the SIT's contribution. Or perhaps just a three position switch.
 
^ Awesome. How far have you tried it?

You could address the myriad of changes and the non linearity (and poor tracking between pots) by using a switch that selects between resistors that are closely matched between the channels.

In essence, don't use a pot.

Or, how about a plug in carrier for R2?
 
Nelson writes some posts earlier
"....... In the diagram below, the output coupling caps have a DC bias and each carries the bulk of the AC from their attached Fet, but in reverse phase. In this manner the 2nd harmonic each would have is cancelled."

In my Spice the currents in the two output caps are not reversed. Only when I turn one cap about 180° the two currents are reverse....

Oh, this spice has more traps than I thought, I need a Ki....
:--))

I always thought LTspice is clever enough to set at least the DC currents itself in the right way using the difference of the voltages left and right of cap or resistor.