| PiTracer is strictly a 16bit/44.1kHz format
transport. It does not come with any 24bit/96kHz nor HDCD compatibility.
"I'd assumed that, with so much processing going
on in the following stages, the contribution of the transport to
the overall sound of today's separate digital components was becoming
less significant. Was I ever wrong! " Jonathan Scull Stereophile,
Sep. 2001 Features:
- Drive mechanism
Direct drive with a highly sensitive, low
inertia, high torque coreless mortor (spindle diameter 3mm).
- Tracking mechanism
Thread drive mechanism with a combination
of coreless motor, Kevlar core thread, and V guide system.
This mechanism was developed to adjust the pickup-head itself
to the off centering of CD. The lens, which changes the angle
in conventional CD transport to adjust to the off centering,
stops its movement almost competely.

It dramatically lessens
the fractuation of the servo amount, also allowing the laser
beam to hit the surface of CD at constant 90 degrees for
greater acuracy of focus.
- Platform
The platform, machined out of 320w x 30h
x 360d mmm aluminum block, contains the spindle motor, sled
motor, worm gear, V guide track, mortor drive amp and output
connectors.
- Head Casing
The head casing is machined out of 270w
x 30h x 170d mm aluminum block. The pickup head (CEC), circuitry
and control keys are centralized on it to release the movement
of the pickup head from the stress of the multiconductor
cable.
- Motor Drive Amp
Four operation amplifiers, same grade as
the one used in 4706 Gaincard, are used to control the spindle
motor and the sled motor. With the combination of the simple
mechanism, we realized a smooth and quick analog management.
- Turntable and Clamper
Both are machined out of solid acrylic.
The CD touches the turntable only at its inside and outside
edges when it's clamped down, minimizing the effect of the
turntable material and overdamping. The spindle and the turntable
were machined again after the assembly using a custom machining
device to ensure the right angle. The exact location of the
turntable, the guide track and the pickup head is also adjusted
by a custom tool developed for the purpose.
Power Supply
PiTracer is powered by Model 4700 Power
Humpty. By adding another 4700, you can power the motor drive
section and the pickup circuitry separately.
Read an article "Designing PiTracer" by
Junji Kimura (designer of PiTracer) |