My paralelled 4780 will drive low impedence speakers well.Even some 2.5 ohm Equinox speakers.It too has a slight buzz though which the maker put down to some earthing problem in the PCB.It does not really seem related to the preamps used.It can be reduced to barely perceptable by turning the gain controls down to about half.Plus installing gain controls means you can better match it to preamps or even use them as a passive preamp-which will sound better than a lot of active preamps.
The3876T amp is very silent.I installed Alps blue 100kohm pots in this without any apparent degradation of the sound.
The3876T amp is very silent.I installed Alps blue 100kohm pots in this without any apparent degradation of the sound.