If by DV 100P you mean the Dynavector 100p it has 63db of gain and 100 ohm loading which be ok with the Eroica though perhaps slightly on the quiet side as you have found.
Reason is that the Eroica L has a significantly lower output (0.25mV) than the later LX (0.4mV). Though with 63db of gain it's still well within the area of being a reasonable match.
Glad your happy (sofar) with ti.
Yes, will be the gain of your PS, as, as a general rule MC carts lose 20dB over their MM cousins, there can be further losses if the loading (Ohms) is way off of the recommended or less than 10 - 12 times the internal impedence if an open ended impedence range is given.
Thanks John - starting to learn a little about MC’s now