The HLLC does not have an upper wattage limit as it does not consume the power, merely looks at the voltage through a high ohm resistor. For any normal installation a 1.4 volt pre amp input would be saturated long before the HLLC would reach its limit.
Proper gain structure should be observed if the receiving input stage/pre amp can be attuned, it should be set so it neither amplifies nor dampens the signal.
Typically the ideal gain stage is as open as possible, just before the threshold of noise in the output. An amplified output will always have some noise, but set the gain structure so there is as little dampening as tolerable when considering audible noise.