Krell's literature and web page state that the
FPB-300cx, FPB-400cx, and FPB-700cx share the SAME
circuit topology.
It's basically a question of how much power does the
power supply have to put into the same circuitry and
how many output devices share the load.
In that matter, the difference is only 1.25 dB.
The "quality" is really a function of how much of the amp's
capacity you are using. The smaller the fraction of the
amp's capacity - the more "linear" the response.
So you have to push a 300cx a little more than a 400cx to
deliver more power - and thus drive it more toward the
non-linear regime. However, you only push it 1.25 dB
more than the 400cx - so the difference will be marginal.
Dr. Gregory Greenman
Physicist
FPB-300cx, FPB-400cx, and FPB-700cx share the SAME
circuit topology.
It's basically a question of how much power does the
power supply have to put into the same circuitry and
how many output devices share the load.
In that matter, the difference is only 1.25 dB.
The "quality" is really a function of how much of the amp's
capacity you are using. The smaller the fraction of the
amp's capacity - the more "linear" the response.
So you have to push a 300cx a little more than a 400cx to
deliver more power - and thus drive it more toward the
non-linear regime. However, you only push it 1.25 dB
more than the 400cx - so the difference will be marginal.
Dr. Gregory Greenman
Physicist