General Information; Power Supply - Lake People SUM-AMP F83 Bedienungsanleitung

GENERAL INFORMATION

The SUM-AMP F83 is a fully balanced sum-
ming amplifier. Its four sections offer two inputs
and one output each.
The basic configuration of 4 x 2 in 1 may be al-
tered by switches on the front panel up to a
configuration of 8 in 1.
When linking sections together normally the
previous output would be without function. As a
special feature the SUM-AMP F83 uses this
prevoius output for signal spliting.
Therefore, SUM-AMP F83 suits nearly all co-
mon splitting purposes. The standard version
offers electronically balanced in- and outputs.
Optionally, either all ins and outs or part of them
can be equipped with balancing transformers.
THE CASE
The grounded case is built from 3 mm alu-
minium and 1.25 mm steel sheet, thus providing
high mechanical stability and ruggedness even
under tough handling circumstances.
Internal signal ground and case ground are tied
together.

POWER SUPPLY

Mains power is injected via a built-in IEC-CEE
socket.
Mains voltage can be set internally to either 230
or 115 V AC.
The "POWER"-switch is located on the front
panel. Active status is indicated by an LED next
to the power switch.
The internal power supply is equipped with a
generously dimensioned toroidal transformer.
To ensure a maximum of headroom, internal
DC voltages are stabilized to +/-18 V.
THE CONFIGURATION
The SUM-AMP F83 is divided in four sections,
they are marked "SECTION A ... D".
Each section is equipped with two inputs and
one output. The level of each input may be ad-
justet by multiturn pots accessible from the
front.
By means of the "LINK" switches on the front
panel adacent sections may be tied together. In
this mannor different summing combinations
are possible. As a special feature the summed
signal is present on all outputs of the linked
section.
EXAMPLE:
When operating the switches "LINK A TO B"
and "LINK C TO D" a summing-combination of
2 x 4 in 1 is realized.
The signals being present on inputs "A1, A2, B
1 and B2" are summed together and are pre-
sent not only at the output of section "B" but al-
so at the output of section "A".
Same is valid for sections "C" and "D".
THE INPUTS
The balanced inputs are situated on the rear
panel, equipped with XLR type connectors.
They are denoted as "IN A1 / A2", "IN B1 / B2",
"IN C1 / C2" and "IN D1 / D2" .
The polarity of the inputs meets AES 14-1992:
1= ground, 2= in phase (+), 3= out of phase (-)
The input impedance is approx. 10 kohms.
While the standard version has electronically
balanced inputs, a transformer balanced versi-
on is available as an option.
The level of each input signal may be varied in
a range of -12 ... +12 dB by meens of a multi-
turn trimpot accessible from the front.
HINT:
Please note that signal summing is done in 0-
ohm summing technic.
This meens when summing coherent (mono)-
signals together, the resulting output signal will
have +6 dB gain.
Whilst summing stereo signals a gain of ap-
proximately +3 dB has to be calculated.
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