Velodyne ULD-15 Input Signal Strength

I am waiting on delivery of a pampered Velodyne ULD-15 to give some foundation to my beloved Spica TC-50's. My home system is powered by a Joldida 302B with the subwoofer option (basicly that option is a line-out from the pre-amp section of that integrated amp). Jolida tells me that this is a very low-gain signal and to not expect the sub to be rattling the windows (which is not what I want anyway). I have read on the AudioReview site that a few reviewers say this sub needs a high-input signal. Does this mean there may be a compatibility problem with the Jolida? Also, I'm running Kimber 4TC's to my main speakers. Would the same cable be adequate for the sub, and should it be kept to the same length? Or are there cables with better low-end that are more suited to subs? I've noticed that some companies are marketing interconnects that are proprietary designs for subwoofers....what's up with that? I've been happy with Kimber PBJ's. Thanks for any input!
It all depends on sensitivity of your Spica. If the main speakers are very efficent, you would have problem even feeding the sub amp directly from the line level output. On the other hand, if they have low sensitivity, you might be fine. Another thing to worry about is the crossover point of your Velodyne in respect to the subwoofer output signal. Velodyne has built-in 85Hz, it is better to set the Velodyne crossover point to about double of your filtered frequency. Let me know if you have more questions.
I'm not quite up to speed on some of this material yet, but as I understand it, the Spica TC-50's I own start to roll off at around 70Hz. They are very musical in the mid and high's, but quite lacking in the bass. In their day (they are no longer being made) they were frequently paired up with a subwoofer. One reviewer suggested a crossover point of 80Hz, which is pretty close to the stock (set) card in the ULD-15. There is a write-up in the Stereophile archives on the TC-50's here: Thanks for your input!