Not from what I’ve heard, that may apply to the Halo JC1’s etc, switched
into high Class-A bias mode, but the standard a/b lower bias mode is
definitely a cooler more etched sound.
I have owned the JC1 monoblocks as well as the A21 stereo amps. Yes, when JC1 is switched into high bias mode, it becomes very warm. However, the standard low-bias sound of the JC1, A21 as well as the A23 and Halo Integrated are all still slightly on the warm side of neutral. It is not at all like Hegel, Music fidelity, Yamaha (and probably Kinki).