@mulveling very apt description of the Ortofon’s sonics through active gain devices. The dry and lean character simply vanishes with a good SUT. Tonearm matching can also make or break them. For example, I had great trouble getting the Anna from mistracking on the tonearms I tried (FR64S, Micro MAX-237, Audiocraft AC-4400 and Exclusive EA-10). So I almost gave up on it until I tried it with a FR64FX on a second turntable. Now it tracks everything with apparent ease and sounds terrific. A complete change of behaviour that I just can’t explain.
Funny you should mention Koetsu as your benchmark. I’ve been having much trouble coming to terms with an Onyx (pre platinum) and I was prepared to give up on it as well. Until I changed around some connections which hooked up my FR64S (silver wire inside) through an Ikeda copper wire tonearm cable to a silver wired Ortofon T-3000. And waddayouknow? The Onyx in a FR RS-141 headshell with Ortofon silver leadwires gave musical bliss! No comparison with any other combination I had tried thus far. I no longer expected this to happen, but I’m glad it did. The Koetsu is now a keeper.