LA Audio EQ231G - Manual (Page 4)

EQ231G User Manual 4
(A 100 Volt special transformer is available for Japan).
(A 220 Volt special transformer is available for the Republic of Korea).
3.4. External connections
The input connector is a female XLR type and the output is a male XLR, both wired as
follows:
Pin 1 : Ground
Pin 2 : Hot Balanced signal
Pin 3 : Cold Balanced signal
3.5. Impedance & Termination
Most modern audio systems (other than telephone lines) have cable runs of less than
100 meters, the devices used usually have very low output impedance and relatively
high input impedance. This allows equipment to be connected in series without regard
to "impedance matching" (as long as the succeeding input is greater than the stated
minimum for the output it is connected to).
LA Audio products confirm to this standard ; therefore inputs and outputs are usually
indifferent to varying load or source impedance. The only exception to this rule is where
the unit is connected to a transmission line or some older vacuum-tube equipment
which requires proper impedance matching. This may be achieved by shunting the
correct matching resistor across the inputs or outputs. The EQ231G has an input
impedance of approximately 20k
Ω
and an output source impedance of 100
Ω
, (20
Ω
with
the transformer option fitted). Its minimum following stage input impedance should equal
or exceed 600
Ω
.
3.6. Signal levels
The unit is designed to accept an input signal level of up to +20dBu (dB referred to
0.775Vrms). Above this, clipping (distortion) of the signal will occur.
It should be noted that the filter amplifiers may be driven into distortion by excessive
boost in the unit, and where this is the case the input signal should be reduced
sufficiently to allow enough headroom.
4. Operating Instructions
4.1. Description of controls
31 Faders are provided on each channel for cutting or boosting at the 31 ISO
frequencies. The frequency is indicated on the front panel as are the amounts of cut and
boost. Each fader has a centre detent, which allows the user to quickly return it to its
inactive position (0dB).
The Master Level controls can attenuate the inputs to infinity or boost them by 6dB.
A Peak LED illuminates when the audio signal is within 2dB of clipping.
The Bypass switches allow the graphic filters to be taken out of circuit for comparison
checks. The adjacent LED's illuminate when the filters are IN circuit.