Wondering if you received a response from Jadis?
On my DA60, beginning in the center of the amplifier and moving through the RCA jacks out toward the end, the first pair is "TAPE OUT", the next pair is "TAPE IN". Not saying you shouldn't wait for the factory's reply, but that second set looks like the safest to try to connect your preamplifier. We CAN exchange photos via email, if you prefer.
Again, curious to hear your impressions of what the Hovland provides and takes away from the overall presentation.
GOOD LUCK!