Careful work....



Testing a cutter



we are goin into details....!!





Before deciding to start audio cutterhead repairs we had burned our first SX68 cutter so many times and we realized the path was not easy!
Sincerely we did not plan to make a job out of it, but after many years of tests we decided to start because of the very good results we had obtained. We also bought destroyed old cutters like Neumann SX15 (bridged type like Ortofon) and, in the year 2000, the way to find the best commercial components to rebuild that was not easy either, for the simple reason that... there are no commercial components, and the only way is to make dedicated orders with best characteristics and measures at high prices to various manufacturers without the certainty of the best final result. So, after maybe 30 and over different tests on Neumann cutterheads in the years with several misuse, Robby found how to make a very good stable repair on that kind of cutter, probably the better known and used in the world from the end of '60ies years for lacquer disc mastering. We can naturally repair Presto old type cutters, because we have experience on that. We can repair Neumann cutterheads SX74, SX68 and, if unavoidable, the SX15 old stereo head (it's extremely delicate with extremely tiny FB coils... sincerely we prefer not to, but otherwise.....) We use the latest technology hi-power flat wires to repair these cutters, so we can upgrade their internal temperature wire resistance to 250°C instead of the 200C of the SX74 and the 120C of the SX68 ! Dont forget that cutterheads and their internal glowes and wires are at least 20 to 30 years old and over! This means it is normal that the original characteristics have been slightly changed or damaged by time and the extreme accelerations caused by the modulation power and aging itself. We can make the check and repairs of these cutterheads with the best wires we found made for us, like the special flat power wire necessary to restore the drive coils with nominal DC resistance, dimensions and mechanical/electrical stability, all with the best wire heat resistance and lightweight to improve the hi-end treble response. We can CHECK AND SOLVE cutterhead instability by re-glow and re-center the feedback system. We can REWIND BURNED DRIVE POWER COILS with the best equivalent high temperature dielectric flat wire produced for US in one of the best US wire factory. Dedicated to tube cutting amp users, we can doubling to 9-10 Ohm the DC characteristics of the SX68/74 coils to obtain the better performances with those amps and the best SAFETY for the internal heat and current. We can upgrade your SX68 winding its power coils with the same hi-temp wire we use on the SX74, so its power capability and performances will be better. With the repaired cutterhead we will give you a printed diagram with the frequency response (without RIAA enc/dec) each channel measured on the feedback coils monitor (with proper FB level, normally -9Db@5kHz) with the Neumann VG66 FB amp. We suggest the re-setting of the feedback level of your new rewound cutter when you'll put for the first time on the lathe after repair, because some difference by the previous old wires will be unavoidable also if followed the original characteristics made by Neumann 30 years ago.

Sab74 The legendary VMS80 SX74 on the VMS80 some cutterheads Robby operates