Triplanar RCA out to Balanced out for MP-1

Nandric, You made me think. The shield for the Triplanar tonearm wires contacts the tonearm body where via the clamp at the base of the mount. So in effect, the shield per se grounds the tonearm body to the preamp. This may be why I never needed to attach the tonearm ground wire to anything. Conversely, I isolated the phono wire shield from the RS-A1 body, where the wires exit thru the holes formerly occupied by the RCA jacks. This may be why I needed to create a separate ground between RS-A1 and MP1. By the way, the hum that I did have with the RS-A1 was annoying but very benign. Not at all capable of damaging a speaker. Moreover, the frequency of hum is way below anything seen by your beryllium tweeter. Fear not.

Lewm and Nandric, this is why I recommend that the tone arm ground wire and the shield both be tied to pin 1 of the XLR. No hum problems! I have even used Kimber wire between the arm and preamp (using an SME V, not a Triplanar) and no hum at all.

A phono cartridge is a naturally balanced source and does not need a special circuit to convert it to balanced operation- just the right hookup.

Dear Lewm, You underrate my Usher BE-20 because they also
'possess' an beryllium 'mid-speaker' and not only.as you suggest, the tweeter. I payd 17.000 Euro for the 'babys' and want everyone to know. According to me you own the
'old' Triplanar VI(?) because I also had this 'model' and
know about the 'shield-connection' to the arm-mass. But because you are in the USA and I in Europa I am not scare of you. Sadly I am not totaly sure about that.In any case I will not mess with the ground-wire because I have bad experience with connection to the pre-ground.
But I was more scared by the proposal of Jb0194. Say 'adding up' solution. I own Emitter II Exclusive + Basis Exclusive + transformers + batterys. In my living-space there is a kind of German artillery situated and I
really think that I have some right for some space for myself. So sorry Jb0194. I know you mean well but there are
limits even for an HI-FI nuts.

Regards,

Nandric, Obviously you need to be comfortable with whatever you do, but I guarantee the hum associated with poor grounding of the tonearm will not hurt your speakers. It's 100Hz or below in frequency; even the midrange is not involved. Moreover, it is low level at normal listening levels, e.g., I was able to listen to and enjoy the RS-A1, hum and all, before I fixed the problem. Congratulations on your expensive speakers, however, and I do understand your desire to avoid damaging them. My Triplanar is about 15 years old, but Herb Papier, the original inventor and manufacturer, upgraded it to VII status as one of his last acts prior to selling the company to Tri Mai. In fact, Tri was visiting Herb to learn the art, when Herb did the last upgrade. I am not aware that there was any difference in grounding the shield or not grounding it at the tonearm side among various versions of the Triplanar. But you may be correct in that inference. Anyway, this is a simple fix.

BTW, My assumption that your hum will be 100hz or below is based on my guess that you live somewhere that has 50 Hz mains frequency. The hum will be at 100 Hz or at 50 Hz, depending upon the rectification of your amplifier. If you live with 60 Hz mains, then hum is at 60Hz or 120Hz.