Table Of Contents
1......The Drive System
Page 3......The Mod
KAB Main 1200 Page
Wanna Know a
Here's something you really must know:
Your favorite records were most likely mastered on a Technics SP-02 lathe
turntable! It's true! click the link here now and see what google returns.
Search Technics SP-02
This is the product that set the
course leading to the '1200; A direct drive motor that inaudibly senses and
corrects for stylus drag.
houses needed a drive system that could inaudibly sense and correct for stylus
It's funny really, with CD, audiophiles decried 16
bits and demanded better. Now there is SACD and DVD-A.
But Analog hobbyists
show little interest in the actual technology. I am betting that if they knew
more about it, then they would demand more from it.
often ask what might have happened if all the money for CD was applied to
analog? Well, something just like that happened when Technics formed the
Special Products Group. Their work produced the SP-02 and the SP
series of transcription turntables finally culminating in the integrated
We will never again see a time like that
when so much talent, technology and resources were brought together to solve a
single problem. We are fortunate to have a product like the '1200 to remind us
of this time. Has any other company shown so much dedication to the turntable?
Gone Without a
Todays audiophile companies do not have the
resources that Matsushita had in the late '70's. That is the main reason you do
not see technology applied to todays turntables. The money required to design
and produce application specific integrated circuits, casting molds, machining
centers... man that takes a large bankroll! [Take the
'1200 factory tour] And you need a large market to justify it. Todays "new
age" audiophile industry has tried to produce direct drive 'tables; but always
found the cost prohibitively high. The latest entry selling for nearly $20,000!
It is a technology best left to the giants.
A Question of
We've all heard the condemnation about how
direct drives fidget and hunt for speed. It remains the most popularly stated
myth today. So I put a 'scope on the 1200's internal self validating
frequency generator and had a look
But 'lo and behold this direct drive motor doesn't hunt or
fidget at all, just a steady sine wave is displayed. Turns out the '1200 is one
of the few designs that uses a linear detection scheme. That means that
corrections are only made when necessary and without rotational delays. [To
be fair, there are some direct drive designs that make corrections only once
per revolution. Thus lending some credibility to the "fidget" criticism. But
then, those players do not achieve wow and flutter numbers of 0.01% ! They are
usually 0.2%]. Some magazines have talked about early direct drive
tables making corrections at 3000hz. I am not sure you could affect the speed
of a 4 pound rotating mass that quickly! But a review of the original SL1200
schematic shows the time constant of the speed integrator to be about 1 second
or about half of a platter revolution at 33.33RPM. The SL-1200 MK2 speed
integrator has a time constant of 300ms or 1/6th of a revolution at 33.33RPM.
So when the '1200 needs to make a correction it
is made gradually and in harmony with the flywheel effect of the 5 lb damped
platter. In other words, the speed stays stable regardless of dynamic and
static stylus drag. No more choking off of dynamics nor is there the wavering
instability that follows loud crescendos. With an SP-02 on the cutting end and
a '1200 on the playback end, the time domain "chain of custody" between master
and playback is preserved.
'1200, the time domain "chain of custody" between master and playback is
Myth #2: Direct drives are criticized for noise, but
in fact are very quiet. some 20dB quieter than many belt drives. This is
because the motor delivers its power to the most rigid part of the platter-
the spindle, rotates at actual
speed, applies power evenly without the side drag of a belt, and unlike most
other drive systems, the power factor is infinitely variable.
motor starts up fast drawing 200mA of current but quickly glides down to an
operating current of just 10mA. With a rumble figure of -80dB, Speed accuracy
of 0.005% and Wow & Flutter of 0.01%, it should be clear to all concerned
that this is an industry standard; Something to be admired, not ignored.
is an industry standard. Something to be admired, not ignored.
Now you know a little about the '1200, come see how
KAB makes it even better.
Click Here to Build Your
Own KAB Custom '1200.