Actually, the DA-A30 is an outstanding power amp, especially in the low-end that is very tight and very powerful. And it can handle the too prevalent low impendance loudspeakers very well. Plus, it is very smooth sounding compared to other transistor amps, even those of today - almost tube-like.
Bridged mono-blocks, very interesting and very rare - should drive a 6-ohm or higher system only - lots-a-watts. Hopefully, they are calibrated correctly.