Manley Langevin Dual Vocal Combo 1999 - 4/2001 LDVC000 - LDVC178 - Manual (Page 15)

INTERNAL ADJUSTMENTS
(see layout on page 16)
1) +45 Volt DC adjust with meter from ground to resistor marked by arrow. Check this first and adjust if
needed. It is the power supply regulator adjustment. Now for the audio ....
You will have to start out by setting front panel controls to these settings: BYPASS mode, SEP / LINK OFF,
REDUCTION controls counter clockwise (MIN), GAIN to 1:00 or unity, Balance at 12:00. The top will need
to be open. There are two screws on the top that hold the top perforated panel in place. Remove these and the
top will slide back.
Be careful! THERE ARE HIGH VOLTAGES INSIDE THE LIMITER. DO NOT HOLD THE METAL PART
OF THE SCREWDRIVER. DO NOT PROBE PROBE AROUND WITH THE SCREWDRIVER OR FIN-
GERS.
The unit should be on for about 15 minutes to allow for “warming up”.
2 & 3) This adjusts thelimiter amplifier gain in all modes. 1 KHz sine at 1.23 volts RMS (+4 dBm, 0 VU) to
both inputs. BYPASS mode. Adjust 2 & 3 for unity gain at outputs.
4 & 5) This adjusts VU meter calibration for OUTPUT. Same input, Meter switches to OUTPUT. Adjust for
0 VU on the Meters.
6 & 7) This adjusts the meter zero for Reduction mode. Meter switches to REDUCTION. Adjust for 0 VU on
the Meters.
8 & 9) This adjusts the meter in Reduction mode to reflect the actual gain reduction accurately. You will
probably need to increase the oscillator 10 dB to get Limiting. Switch from BYPASS to IN. Meter switches
to OUTPUT. Adjust GAIN controls to get 0 VU on the METERS again, then adjust REDUCTION controls to
reduce the signal to -4dB. Switch METERS to REDUCTION. Adjust 8 & 9 to get -4 dB on the METERS.
10) This adjusts the gain of the right side chain and adjusts the side chain balance in Link. Switch the LINK
ON. There should be 1 to 2 dB change in the Meters. Adjust 10 so that the meter is the same for both sides.
You may have to re-adjust 8 and 9. Check that both in LINK and SEPARATE that both channels show the
same reduction.
11) Sets the gain for each channel’s Mic Pre. Use a low level input in the mic XLRs and adjust each channel
for 45 dB of gain with the Input Attenuator wide open fully CW.
12) Sets the Direct (Instrument) Input gain. Use a low level input in the 1/4” front panel jacks and adjust
each channel for 25 dB of gain with the Input Attenuator wide open fully CW.
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