Whereas, Dave said that any device with an input impedance much lower than that of the cartridge internal resistance can act as a current driven stage. Is that correct?
I am not suggesting that if the load is a fraction of the cartridge impedance the stage must be a current amplifier.... I am suggest as a whole current amplification stages will typically load a cartridge with less than its internal impedance.
A good example of this is the situation I outlined above where I used an 8Ω cartridge through a 1:8 SUT and then directly compared it to a 1:40 with a 2.2Ω resistor across the cartridge directly. The 2.2Ω resistor was chosen so that the output of the SUT in both cases was identical as was the frequency response from 10Hz to 100kHz. (±1dB). In this case even though the cartridge load was 1/4 the internal impedance when using the 1:40, I would still consider it a voltage gain stage.
The result of this experiment was interesting. Even thought the gains of both situations were the same, the 4.7kΩ load through the 1:8 sounded a good 2dB louder. When the gain of the 2.2Ω load was bumped 2dB suddenly it was preferred and then going back to the 4.7kΩ 1:8 at the same +2dB level started to hurt my ears.
dave