7
Advantages of the SPL dual-stage preamplifier
The GoldMike's engine is the newly designed SPL dual-stage
preamplifier. During the first stage of amplification the signal is
amplified by a semi-conductor circuit while the second stage
applies tube electronics. We achieve a high common-mode-rejec-
tion by using laser trimmed components. Likewise, minimal noise
and distortion figures distinguish our high-quality preamp.
Analog Device's semi-conductor (SSM2017) is very unreceptive to
HF and hum interference, and is perfectly integrated by the PCB
layout; wide PCB conductors guarantee a stable power supply
even when extreme level changes demand an immediate current
supply. The star ground wiring scheme ensures a quiet electronic
performance. The dimensions of the PCB conductors, and their
respective layout (wide or narrow), were especially designed for
the integration of tubes and ICs in the preamplification circuitry.
The MIC GAIN potentiometer adjusts the semi-conductor stage,
allowing amplification up to 2200 times the original signal. The
following secondary tube stage adds a constant 6 dB of gain;
therefore, the same amount of tube character is added regardless
of amplification. The MIC GAIN should be adjusted for a "0" VU
meter reading. At this level the best signal-to-noise performance
is achieved and the tube will perform in its ideal sonic range.
(Please note that the VU readings are not peak PPM but average
levels. In other words, watch out for the meter hitting the red.)
In summary, our dual-stage design maximises the amplification
power and signal-to-noise performance of the SPL semi-
conductor at the first stage and then maximises the warmth and
liveliness of a meticulously selected and tested ECC 83 tube at the
second stage. This makes the GoldMike an ideal partner for high-
end HD recording. The unit's dynamic range of 111 dBu even
outperforms some 24-bit recording gear.
Advantages of the dual mono design
GoldMike's two mono amplifier blocks are designed with a
central power supply that utilises a star ground wiring scheme.
Chief advantages of this particular layout are the excellent
channel separation and, respectively, the low crosstalk figures.
In your daily work you will find many practical applications for
these advantages. You may use the GoldMike's channels for a
snare and a vocal (arguably the most important elements in a
mix) simultaneously. Stereo recordings, benefiting in particular
from the low crosstalk figures, will have wider stereo depth and
precise spatial definition. Another advantage of the central power
supply with a star ground wiring scheme is that the two indivi-
dual circuitries, operating discretely, can deliver identical sonic
performances per channel. The current demands of one channel
(i.e., snare) are not compromised by the current demands of the
other channel (i.e., vocal). All power supplying conductors, layed
out identically and symmetrically, provide both channels with the
necessary current.
Tech Talk
The GoldMike combines superb
signal-to-noise specs with not only
the amplification power of semi-
conductors but also the warmth
and liveliness of tubes.
An outstanding dynamic range of
111 dBu outperforms even the
average 24-bit recording system.
Dual-Mono-Layout, with central
power supply and star grounding,
delivers excellent
channel separation
• two discrete signals (snare, vocal)
may be recorded simultaneously
without crosstalk
• precise spatial definition
• identical sonic performance
per channel
