Input Wiring
Your DA-770-2 Series amplifier is provided with a 3
conductor Phoenix Type connector for each input.
The connector may be wired Balanced by connecting to
Ground – and + as marked on the chassis over each
input. If you wish to operate the amplifier unbalanced,
connect your line across Ground and + and add a
jumper from – to ground.
Output (Speaker) Wiring
Your DA-770-2 Series amplifier is provided with a two
conductor Phoenix Type connector for each output.
The connector may be wired by connecting the speaker
line to – and + as marked on the chassis over each
output.
Bridging
Bridging of the DA-770-2 Series is possible to achieve a
140V line. This may be accomplished by feeding the
signal to input 1 and inverting the signal to input 2.
Both gain controls must be set to the same setting,
typically
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High Frequency Switch Mode Power Supplies
The foundation of all amplifier design is the power supply. For
years Stewart Audio has pioneered leading edge, power supply
technology. All Stewart Audio amplifiers feature a High-
Frequency Switch Mode Power Supply. Because of this use of
advanced technology some explanation is in order.
Conventional Power Supplies operating at 60 Hz (standard line
frequency) recharge only 120 times per second, requiring their
storage capacitors and transformers to be quite large to supply
the energy needed during the intervals between cycles
when power is not available from the wall. The power supply
must act as a local reservoir of power from which the amplifier
circuits draw. This storage function is responsible for much of
the bulk, weight and cost of traditional power amplifiers.
Stewart’s famous, High Frequency Switch Mode Power Supplies
fully recharges 1000 times faster than conventional supplies,
requiring far less capacitance for filtering and storage. This
high-speed recharging reduces power supply “sagging” com-
mon with other designs.
The
New DA-770-2 Series Digital Amplifiers
utilizes a new,
regulated, forward converter design Switch Mode Power Supply
operating at a frequency 2/3 faster than our old standard sup-
ply.
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