It was me who pondered that there might be a SUT inside not Lew. I realize that many MC inputs offer a 100Ω option but I found 100Ω as the only option to be a bit odd particularly for something likely to be paired with a 40Ω denon 103. Add to this that there are many who insist that a MC cartridge should be loaded at 47kΩ and the single 100Ω option seems like a very limiting choice for any active circuit but a perfectly logical one for an internal SUT.
dave