Saturday, 6 April 2013

SME Conversion Part 3 – The First Test – Tonearm Conversion of Classic SME Tonearms

When I got the finalized weights from the galvanizing company I had the tonearm wands from Switzerland already here. I took a 3012/II with typically exhausted rubber damping in the extension tube and made a complete conversion with the new parts. I was happy that all wholes and connection points did join perfectly the vintage parts. Within three hours I had changed the wand to a stainless steel version. I had implemented a new wooden damping piece, drafted a new set of cables and finally installed a new silicone rubber damper in the extension tube. I did clean all mechanical parts, inspected the knives and the pillar bearings and soldered the cables to the headshell socket (extremely difficult operation, more about this step in a own post soon) and to the basic connector and reinstalled the tonearm at my turntable.

In combination with a Ortofon SPU in its original headshell (32 g), the 55mm long wayrod from the 3012/II I could not balance my 220 g weight to zero. The weight is to heavy. In that moment I did realize that I did copy the original weight from the very first version. This first weight was made for the first SPU with built in transformer, which was heavier than 32 g. The later transformerless versions did need a lighter balancing weight, which I had seen sometimes. I asked a friend of mine who had this weight to measure it and immediatly I did ring Mr. Kuhs to order a second set of weights with 160 g mass. It took me another two month till the smaller weight was finished to match the other weights. Now I could balance my SPU perfectly and I could listen to the converted SME for first time. It was a very pleasing first impression and I was satisfied that the new arm improved in almost any discipline the aluminium version.

Next step was to convert a second 3012/II with pure silver wires (0.1 mm solid silver 4N) to be able to compare it with the existing one with inner OFC copper cables. I did the conversion with the solid silver wires, which are so hard to come by. In the image you see at left the silver wire with silk insulation, right some teflon insulated silvered copper litz. It took me two years in research to find a manufacturer for the solid silver wire in 0.1 mm strenght and with silk insulation. To my knowledge I do not know any other maker of tonearms who uses solid wires. From my long term experiences with tube amplifier construction I learned that solid core connections always sounds a lot better than the same material as litz. So it was a must for me to find the thin solid silver wire to improve the SME further on. I do like the solid silver cable a lot better than other inner cables I did test. But the main improvement comes in comparison with my Ortofon SPU Gold. It is a limited edition of the late eighties from Ortofon for the japanese market with silver coils instead of the cordinary copper coils. Here the silver armature of the Gold can show a lot of improvement over the standart SPU. If I use all the way silver wire interconnects from tonearm to step up transformer on to the preamp the silver brings is a hughe advantage. I would recomend the inner silver wires to everybody with a phono equalisation of high resolution abilities, the improvement is tremendous. Here the silver wired step up transformers from Lundahl with the AG ending in the name will complete to perfection at the predeamphasis stage.

Read on soon, Volker