|
|
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 200°C of
the SX74 and the 120°C of the SX68 ! Don’t 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.
WWW.CUTTERHEADREPAIR.COM |
