If you listen to vinyl, the combination of the WLA12A and the WPP100C will give you the greatest level of performance at far less cost than the competition. The output impedance of the WPL10V is listed at 2000 ohms, the WLA12A at 1K, and the WPL100A is 600 ohms, but they will drive 600 ohm loads with negligible loss of output level. Both preamps will drive most power amps. All of the power amps are near-selectable to operate 4,8, or 16 ohm speaker loads. 47K ohm moving coil and moving magnet cartridges.
Lower impedance moving coil cartridges require a step up device.
We do not use a lot of silver or silver plated wire in the product. Most of the audio is coupled directly from one socket through the components to the next socket. By shortening the signal loop, we eliminate stray capacitance that comes with longer leads and the need for silver wire. I've got 107dB-sensitive speakers. The WPA3.5 Mono amp, along with WLA12A line stage, is ideally suited for high-efficiency speakers.