There are two versions of the Aristo VC lamp(s).
One is a single lamp of distinctly cyanish cast usable with VC paper (I have one, it is the V54 lamp). It works well with filters, although the filter / contrast results are not as linear as with incandescent enlarger bulbs, and the exposure differences between filters do not necessarily follow the info that comes with the filters. For me it is worth it due to other advantages of cold light lamps. The bulb also works well for split filtering, and the total range of contrast is considerable, I think more than a normal incandescent bulb with VC papers. At least, I have never seen as extreme a grade 0 or 5 with any other systems, including graded paper. This version came with either a normal head, or one with a filter drawer, which is the one I have.
The other Aristo product was a dual lamp system, and you dialed in how much of each lamp for contrast (no filters), as ROL indicates above. This arrangement required more exposure time and was more expensive for the bulb(s).