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This is part of the POPPY Records range of professional transcription services
Please contact
us to enquire about
hiring
this machine The POPPY RECORDS wax cylinder playback machine is a
high quality precision-engineered instrument which meets the
most exacting archival standards. it features:
The pickup arm contains a sensor which measures the
instantaneous radius of the cylinder and adjusts the mandrel
motor speed so as to keep the surface speed constant. This
reduces the wow of warped and eccentric cylinders to
negligible proportions even if they are not accurately
centred on the mandrel.
When playing archival cylinders this feature saves a
great deal of time as there is no need to accurately centre
each cylinder in order to play it properly. If the cylinder
is mis-shapen, a simple shim may still be required - but
tedious and time-consuming fine adjustments of the shimmming
or mandrel offsets are entirely eliminated.
The mandrel is driven by a stepper motor with analogue
electronic waveform generation giving smooth control over a
wide speed range. The operator sets the speed by means of
dial which has 1000 divisions and a linearity of better than
1%. A stroboscope allows a quick and accurate check that the
system is in calibration
The pickup is mounted on a carriage driven along
bedways by a leadscrew. The leadscrew motor is controlled
from an optical sensor connected to the pickup spindle
bearing which is arranged to maintain the pickup at the
correct angle and move it at the correct speed, regardless
of the tpi of the cylinder
The machine is equipped with a mandrel to the Edison
standard, which suits the majority of commercial
entertainment and dictating machine cylinders. Special
alternative mandrels can easily be produced to suit
non-standard or particularly difficult cylinders.
The pickup arm is equipped with a Shure 44 cartridge
with interchangeable stylus. A wide range of different styli
is available for this type of cartridge, so it can easily be
adapted to suit almost any groove shape.
Because the pickup arm is short and made as an
anti-resonant sandwich construction from special low-density
materials, it has a low inertia and is able to accurately
track warped cylinders with low tracking weight.
To reduce the possibility of groove damage caused by
lowering the stylus onto the wax surface, the pickup is
controlled by a hand-operated lift/lower mechanism which
allows it to be manipulated accurately and gently. A cam
gives a variable ratio of leverage so that the precision is
greatest where it is most needed. This is particularly
important for warped or eccentric cylinders, where
hand-lowering would be a very risky procedure.
The mandrel and leadscrew are driven by stepper
motors. This type of motor has acquired a bad reputation for
being noisy, a reputation which is well justified in many
designs using off-the-shelf controllers. The controllers in
this player have been custom-designed by Poppy Records to
give drive waveforms which generate the least amount of
vibration from torque variation in the motors. Warped cylinders can generate high levels of rumble
and this is often exacerbated by the transfer
characteristics needed to obtain adequate bass from acoustic
recordings. To prevent overloading of any subsequent signal
processing or recording devices, the player is equipped with
a switchable rumble filter with an 8-pole Butterworth
characteristic giving a 48dB per octave slope.
The archival "Playback" copy of a cylinder can often
benefit from a certain amount of bass lift. If required,
this can be applied to the Playback signal by means of a
dial calibrated in microseconds. By logging the dial
setting, removal of the characteristic from the recording at
some future date (should this ever prove necessary) becomes
a simple and accurate process.
The signal amplifer chain has been designed in its
entirety by Poppy Records so as to give the lowest possible
distortion and background noise level. High quality
components are used throughout, so as to ensure a long life
with stable characteristics.
The player has four output signals:
Right Channel
Mono
Mono processed These permit the recording of several different
"Archive" and "Playback" combinations to suit the
requirements of different archives and authorities. Each
signal is fully buffered and independent of the others, so
that a fault or change of conditions on one recording
channel does not affect any of the others.
The output levels are nominally 0dBm into 600 ohms
balanced and centre-tapped to earth. Levels up to +20dBm may
be generated without distortion so as to faithfully
reproduce transients from damaged cylinders.
Standard BBC/GPO jacks are used on all channels.
Speed control accurate to better than 1%
Very light stylus pressure with low inertia
arm
Each motor is resiliently suspended from a weighted mounting
platform, which in turn is resiliently suspended from a
massive cast-iron mechanism bed-plate. The motor drive
shafts power the drive train through special resilient
torque couplings having a high degree of damping to prevent
resonances from building up at any speed within the working
range.
Left channel