SEMI-TECH subsidiary Pfaff, Germany's largest listed sewing machine maker and distributor, has cut losses to 11.1 million deutschemarks (about HK$50.17 million) from 50.9 million marks before restructuring costs. Restructuring changed the picture, pushing the loss to 68.7 million marks in 1992 and 87.1 million marks last year. Turnover fell eight per cent to 867.4 million marks from 943.2 million marks in 1992. Semi-Tech chairman James Ting said he was happy with the result. ''The turnaround demonstrates the soundness of Semi-Tech's philosophy of identifying investment business which will benefit from expertise in restructuring, marketing and finance.'' He said he expected the group to recover further this year with production of sewing machines shifting to Zhuhai in the middle of the year.