I'm not sure if it's an affinity between the Parasound JC 2 BP preamp and JC 1 amps, but since I introduced a pair of the JC 1 amps the KEF 107/2s sing in a way they never did with the Proceed HPA 3. Organ pedal notes pour out with an authority new to me. The HPA 3 is three monoblock Levingston amps each rated at 500 watts into 4Ωs; the JC 1 amps are monoblocks rated at 800 watts into 4Ωs, but a single JC 1 is the same size as the three amp HPA 3. I suspect the difference may be current delivery. With the low bias setting I use, the amps run class A to 10 watts -- 25 watts with high bias, but they do get hot. In any case, even though the 107/2s are rated as having a sensitivity of 90 dB, my experience suggests they sound best with powerful amps. Driven with the JC 1 amps, the 107/2s reproduce a wide frequency range with great authority and transparency.
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