DESCRIPTION
DESCRIPTION
DESCRIPTION
DESCRIPTION
DESCRIPTION
6
6
6
6
6
AMPLIFIER SECTION
AMPLIFIER SECTION
AMPLIFIER SECTION
AMPLIFIER SECTION
AMPLIFIER SECTION
Differential voltage gain throughout provides
exceptional rejection of external noise and
contributes to the inherent stability of the circuit.
The unit also uses output followers operating
without feedback.
The front end is designed to provide a slew rate
of 50 V/us without entering class B operation as
is common in many other designs. This com
bined with excellent high frequency design
insures linear operation at high speed. The
supplies take a very direct approach to high
performance. A top quality toroidal transformer
capable of
2,000
VA is utilized, and 4
0
,000 uF of
total capacitance assure an overbuilt power
supply.
The current stage is capable of producing peak
current outputs in excess of
50
peak Amperes
with a degree of linearity and speed which is not
matched by other designs when producing only
a fraction of this current. This is achieved by the
implementation of several distinct circuit fea
tures.
Each channel uses 1
8
individual output transis
tors with a combined power rating of
3,600
Watts
and 75 Amperes and a bandwidth of 10 MHz.
The Unison 3.3 operates in Class A up to approx
imately 7 Watts. At higher output levels, the
amplifier slides into Class AB operation. The bias
section is designed to produce a precision trans
ition with no abrupt changes in distortion or output
impedance. This "Precision Bias" technique yields
seamless performance regardless of the complexity
of the load impedance. With such linearity and
bandwidth no overall feedback correction is used.
One advantage of this is a high degree of immunity
from interactions with complex speaker loads or
cables.
The AC power entry module has a line fuse, a
spare fuse and a power switch. Since the power
draw is low, the preamp may be left on, except
when installing, changing cables, or changing
system components.
