Thursday, 4 April 2013

SME Conversion Part 1 – The Arm Wand – Tonearm Conversion of Classic SME Tonearms

The early SME has so much better dynamics and improved trackability with the SPU that it seems to be in a own class. So I decided in 2006 to try to find a company which might be able to produce stainless steel arm tubes with 0.5 mm material thickness in order to make a limited amount this unique qualities accessible to a wider community of vinyl lovers. I thought it might be quite easy to find somebody who can bend the tubes exactly like the originals and than only has to drill some wholes into the tube. Almost every classic SME tonearm than could be converted to the rare unsurpassed quality of the almost unobtainable MK1 type.

I thought. But reality learned me quickly how difficult it is today in globalized Europe to find a manufacturer able to do such a easy looking job. It took me half a year on research to find a company able to bend small tubes precisely. After unsatisfying test results from different companies in Germany, I had to search again and again. All samples which were made had one comon argument: poor craftmanship with lots of tolerances and unacceptable tolerances. Finally in Switzerland I found a company which is specialized in the production of medical probes. Their main business was bending stainless steel tubes in diameters between 0.4 to 10.0 mm for several probe types to closest tolerances. A inquiery through email ended up two days later in a telephone call where a friendly man with nice swiss accent made me hope that they can do the job to my high specifications. They even had a 9.5 mm stainless steel tube in storage (with 0.2 mm material strenght) in small amounts available for some tests. A thicker walled tube had been difficult to come by, one manufacturer offered me a special production with minimum of 300 m to take with a price of 25$ for the meter, just for the tubes!
The test bendings in Switzerland ended up in a desaster. They tried to bend the 0.2mm material tubes cold, as well glowing, filled or open, bursted tubes came outThey dehardened the steel first and tried to bend again without any usable result. The only available 9.5 mm tubes had been to thin to bend. After a year I gave up the project, the banking crises started and I did store my ideas in the shelf "good ideas, but not realized".

In 2011 I found just by accident a supplier of tubes who was able to sell 9.5 mm stainless steel tubes with 0.5 mm wall thickness. And this company was round the corner and open to sell any amount I did need. So I bought two meters of it first and send them to the swiss company to make a second set test bendings possible. This time it came out to be perfectly usefull for my projected tonearm wands with closest tolerances and a perfect finish of the surface. So the old idea was newly born to make the MK1 tube as a conversion kit available.

Read on soon, Volker