The problem with doing a lower power Fet Valve amplifier is that it would still need all the same separate power supplies.
The high current, high voltage raw power supply for the output mosfets, followed by separate regulated output circuit power supplies for each channel
The high current low voltage raw power supply for the tube heaters, followed by separate regulated 12V heater supplies for each channel.
The low current high voltage raw power supply for the tube plates, followed by multiple regulated power supplies for each plate of each tube and the small signal mosfet.
It would still need all ten separate regulated power supplies as in the 400R and 600R.
So all the base supporting structure would still be there and there would only be minimal cost savings in trying to scale things down.
It would cost nearly as much as a 400R and thus would be an impractical choice for us to offer or you to buy.
Be happy that the amazing Fet Valve 400R 225W/ch hybrid amplifier starts at $2700 and not $10,000.
Note that David Janszen, designer of the great Janszen electrostatic speakers, just bought a second 400R, this one wired for 240V just to have one available for the Munich, Germany show later this month. He has never heard any amplifier perform better driving his electrostats.
Regards,
Frank Van Alstine