Manley ELOP+ Owner's Manual page 13

9. Servicing
CALIBRATION / INTERNAL ADJUSTMENTS - FOR EXPERIENCED TECHNICIANS ONLY*
Before starting any procedure, please set the front panel controls to these settings & remove the top cover;
BYPASS mode, LINK OFF, REDUCTION controls counter clockwise (MIN), GAIN to 1:00 or unity, S.C. at "Flat".
THERE ARE HIGH VOLTAGES INSIDE THE ELOP+. DO NOT HOLD THE METAL PART OF THE SCREWDRIVER. DO NOT
PROBE AROUND WITH THE SCREWDRIVER OR FINGERS. The unit should be switched on for about 15 minutes
to allow for the correct "warming up" period. If you can use an insulated trimming tool.
(1) Unity Gain Adjust 1
This adjusts the tube amplifier gain in all modes. Apply 1 kHz sine at 1.23 volts RMS (+4 dBm, 0 VU) to both
inputs. BYPASS mode. Adjust (1) for unity gain at outputs.
(4) & (7) Output Adjust
4 7
This adjusts VU meter calibration for OUTPUT. Same input, set Meter switches to OUTPUT. Adjust for 0 VU on
the Meters.
(5) & (6) Zero Meter Adjust
5 6
This adjusts the meter zero for Reduction mode. Set Meter switches to REDUCTION. Adjust for 0 VU on the
Meters.
Switch from BYPASS to IN. Meter switches to OUTPUT. Adjust GAIN controls to get +4dBu on the METERS
(2) & (8) GR Adjust
2 8
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. Adjust REDUCTION controls to reduce the signal to
-4dB. Switch METERS to REDUCTION. Adjust (2) & (8) to get -4 dB on the METERS.
(3) Link Balance Adjust
3
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 (3) so that the meter is the same for both sides. You
may have to re-adjust (2) & (8). Check that both in LINK and STEREO that both channels show the same
reduction.
Final Check
This is a final check to verify that all adjustments are OK and the unit is ready for use. Confirm that 0
VU on the meters is +4 dBm with an external VU meter or VOM that reads between 1.22 and 1.23 volts AC
and that gain reduction reads the same on OUTPUT and REDUCTION and that LINK or UN-LINK does not
reduce the gain unevenly on the two sides. Remove the power lead and screw the top cover back on to the
ELOP+.
1
2 8
2 8
* Experienced Technicians Only
The calibration procedures mentioned here
are to aid the servicing of the unit. They
should only be attempted by a skilled
Technician. These adjustments should not be
attempted by the user without experience.
Trimming these potentiometers without the
correct understanding will result in poor
performance of the unit.
3
11