DYNAMIC SOUNDS ASSOCIATES Phono III
Page 14 of 38
USER MANUAL
Note:
Using the “reset”, shown in Figure 1B, will “zero out” the “baseline” loading values in the memory
for the selected input.
3.5
Adjusting Cartridge Azimuth Angle
The “L-R/R-L” function can be used to adjust cartridge azimuth alignment; however mono source
material is required for this adjustment. The approach relies on the differencing of the signals from the
left and right channels. Azimuth alignment is set when there is zero (or equal but very low) signal in
both the L-R and R-L settings.
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The steps to be followed are as follows:
1.
Place a monophonic record on the turntable
2.
Switch the
Phono III
to the mono mode
3.
Push the “L-R/R-L” button and play the record
4.
While “toggling” the phase button, listen to the speaker output and adjust the azimuth angle of
the cartridge to obtain a minimum sound level in each position (L-R and R-L).
5.
When satisfied, switch back to the stereo mode.
4.0
DESIGN PHILOSOPHY AND IMPLEMENTATION
The solitary goal of the Dynamic Sounds Associates (DSA)
Phono III
is to provide the finest possible
reproduction from LP recorded media. To achieve this goal, the
Phono III
is based on a “no-compromise”
dual channel design using best engineering principles and the finest of components. The
Phono III
does
not employ any form of loop feedback to achieve the desired throughput gain or the proper playback
compensation. Instead, each gain stage of the
Phono III
has internal feedback to ensure that all forms of
distortion are held to very low levels. The playback compensation is provided through the use of passive
low-pass networks, with the proper time constants, located between the gain stages of the amplifier
chain. This approach provides low distortion plus a very high dynamic range. It also eliminates transient
inter-modulation distortion, which is a common byproduct of configurations where the throughput gain
and playback compensation are achieved through the use of inter-stage loop feedback.
Furthermore, because even the finest of coupling capacitors can cause minor, but perceptible,
degradations in the reproduction of the audio signal, the
Phono III
has no coupling capacitors in the
audio chain from input to output. Yet, through the use of an innovative design it remains very stable
and resistant to DC drifts. Additional advantages of the design approach are the ability to provide easy
polarity inversion of the audio signal and a true monophonic capability for the proper reproduction of
monophonic LPs. Combining these two capabilities leads to the L-R and R-L capability in the mono mode
which is used, as described, in
Section 3.5
.
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There are other methods for adjusting the azimuth angle that rely on minimizing channel cross talk. The use of
these approaches may be beyond the capabilities, or resources, of many audiophiles; and, we believe that the
approach described in Section 3.5 will prove satisfactory in most instances.
