Lukascheck PP-1 Phono Stage
Price:
$1,350.00
The
small size of the PP-1 allows close placement to the turntable,
minimizing signal leads from the tonearm. The whole power supply is
inboard the PP-1 chassis except for an external power transformer,
which is outboard to eliminate magnetic field interaction.
The miniature size of the PP-1 also allows all circuit components to be
very close to one another. This significantly reduces circuit board
traces, which could introduce noise and sonic degradation. The PP-1 is
optimized for moving coil amplification, thus does not provide switches
and or jumpers for gain setting or resistive loading. This elimination
of unneeded circuit junction points preserves the low noise/high
performance characteristics of this superb phono preamp.
By using only 2 transistors in each amplifier stage, perfect stability
and extreme fast transient response is achieved. This provides the high
degree of transparency and accuracy of the PP-1. High quality
double-sided glass epoxy circuit boards with carefully designed
topology (CAD) have been applied in order to ensure shortest possible
signal paths. Low noise matched bipolar transistors were selected for
this purpose. All resistors are high quality metal film with 1%
tolerance. Within the RIAA network, only 1% polystyrene capacitors have
been used, with high quality metalized plastic-film capacitors in the
coupling function.
Each channel of the input amplifier stage works around a phase
non-inverting 2-stage negative feedback amplifier. Available gain is
set at 40dB and the upper frequency limit has been set at 650kHz/-3dB.
Input impedance has been set at 22k Ohm in order to eliminate
interconnect cable and phono connector influence on the sound quality.
A 10Hz sub-sonic filter has been incorporated between the input stage
and the RIAA equalizer.
As with the input amplifier, RIAA equalization has been achieved
through an inverting 2-stage amplifier of ultra high accuracy (+0/-.5dB
within the RIAA standard). Available gain is 22dB/1kHz and it has an
extended high frequency roll-off. This section of the PP-1 connects
directly to the output of the unit. Total gain of the PP-1 is 62dB,
ideal for cartridges with output as low as .2mV. |
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In
his latest revision of the PP-1, Albert Lukaschek has redesigned the
regulation circuitry of the unit's power supply, bringing
across-the-board improvements in the areas of clarity, focus, and bass
control.
Integrated circuits are now employed
only in the pre-regulator, which provides a constant 25 volts to the
independent regulators for each gain stage, which are now implemented
with fully discrete transistor regulators.
The improved speed and impedance characteristics of these transistor
regulators, which are now direct-coupled, bring across-the-board
improvements in the areas of clarity, resolution, and focus as well as
low frequency control, articulation and heft.
The new active-load, constant-voltage-source regulator allows the first
gain stage to function to its fullest potential. This linear amplifier
stage can now utilize a full 100X gain factor, an increase in open-loop
gain over previous versions, which allows not only for improved
signal-to-noise performance (vital for high-gain phono stages), but
also provides better coupling to the RIAA filter and output stage.
This stage is also individually regulated with discrete transistors in
a constant-load configuration. Lukaschek finds this new regulator, in
conjunction with his polarity inverting RIAA filter, yields reduced
distortion and a more exact implementation of the RIAA equalization
curves.
The increased resolution afforded by these improvements exposed
previously inaudible artifacts due to circuit board layout. Lukaschek
then spent a number of months optimizing component placement and
circuit-board trace layout, before the final revision was complete.
The net sonic result is a PP-1 of far greater refinement than any
before. Tonal balance is slightly warmer than the previous versions,
yet with far more resolution and extension. Bass is bigger and more
solid; highs are effortless, open, transparent and totally devoid of
smearing. Focus, soundstage depth and dimensionality, particularly on
the edges of the soundstage, are much improved.
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Lukascheck PP-1 Phono Stage
