Empire 4 Channel Phono Cartridges 

1974.
4-Channel cartridges require a total system capacitance (tonearm wiring, audio cables, and preamp circuitry) of 100 pF. Typical stereo systems have a total load of around 200 - 300 pF and at that level,
4-Channel cartridges have a high frequency roll-off wth a sound that is muffled. For optimum performance (for both stereo and quad systems), a low capacitance system plus a 4-channel demodulator is required. The demodulator has filters that keep the frequency curve as flat as possible throughout the audible frequency range.
In a previous video I used standard stereo equipment with a load of around 260 - 280 pF; the results were disappointing.
This time I used low capacitance audio cables that brought the load down to around 180 pF. Still above Empire’s recommendation of less than 100 pF, but at least the treble roll-off is not as drastic as before. I do not have a demodulator and sense the low frequencies are a bit thin (the canon shots could be a bit stronger ?). In any event, the 4000D cartridges will sound their best using a quad system (or at least with a system load of less than 100 pF and a quad demodulator.