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First, it removed the wildly varying DC bias voltage component
from the audio signal on the plates of the variable
transconductance tubes, leaving only the audio voltage present
on the secondary winding.
Second, the signal balance of the recovered audio signal
voltage could be maintained in near-perfect push-pull
complementary symmetry by virtue of constructing a pair of
identical coils for the inter-stage transformer secondary. The
signals on the secondary would then be fed to the make-up gain
stage, or, as in the case of the good old Fairchild 660 /670,
directly out to the line-matching output transformer.
But this approach was not and is not without compromise. Wide-
band high-performance inter-stage transformers, then as now,
are complex and expensive components, which, at best, impose
rather severe bandwidth and phase limitations on the audio
signals passing through them. This especially true when
connecting a transformer with fixed characteristics to tubes
whose output characteristics are intentionally changing on
command. Basically, as the variable transconductance tubes are
biased into heavy gain reduction, their ability to push the
transformer is reduced. This can and does induce a certain
amount of degradation in the audio path. One may expect, for
starters, elevated levels of distortion at the band edges, and
an overall drop in bandwidth (dulling of high frequencies,
thinning of deep bass notes) during compression.
The Glory Compressor features a novel hybrid servo system,
which cancels the fluctuating DC control voltage in the
recovered audio from the variable transconductance tubes in an
active all-electronic manner. This leaves only the balanced
audio signal, without resorting to inter-stage transformers.
The variable transconductance tubes are loaded only with
forgiving, purely resistive loads. This provides the user with
an all-tube variable gain cell whose high bandwidth remains
constant during compression! Remarkable! Fun is waiting for
the user, as the Glory Comp throws open new tonal territory in
high-bandwidth vacuum-tube based dynamics processing.
The Output Stage (Too loud, man.)
The Glory Compressor follows in the footsteps of the venerable
VIPRE microphone preamplifier in its internal all-balanced
signal path architecture, and in its prodigious output signal
level capabilities. In the spirit of professional production
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