Ampetronic MLD5, Руководство по установке

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Ampetronic MLD5 Installation Handbook Page 5
Note: To avoid unwanted stray magnetic fields the feed cable should be tightly twisted or star-
quad connected.
3. Connect the signal inputs appropriately:
Microphones: Suitable dynamic or condenser microphone with balanced cable feed. Select
phantom power as required. Connect to INPUT 1 and INPUT 2 (with selector switches in the
appropriate position) using a 3-pole XLR plug wired as per Connections drawing.
Line level signals: From other audio equipment such as PA system, mixing desk or CD player.
Connect to INPUT 1 and INPUT 2 (with selector switches in the appropriate position) using a
3-pole XLR plug wired as per Connections drawing. You may use either or both inputs.
 
 
Do not run input and output cables close together
4. Connect AC power to the MLD5. See points 6 and 7 in Safety section.
5. Switch ON. The ‘ear’ symbol will flash for a few seconds whilst an internal self-test is performed
and the loop resistance is tested. If both tests are successful, the ‘ear’ symbol will illuminate
continuously and the unit will be in an operational mode. If the ‘ear’ symbol continues to flash, or
one or both LOOP LEDs illuminate, consult the Troubleshooting section.
6. Select one input and apply a suitable audio signal (ideally a CD player with music or continuous
speech applied to one input, with no connection to the other). Turn the associated input control
clockwise until two COMPRESSION LEDs are illuminated on the peaks of the signal.
7. Turn CH A CURRENT control clockwise until the target current is achieved – as indicated by
the CH A CURRENT LEDs. Note that consecutive LEDs illuminate at 3dB intervals. Turn CH
B CURRENT control clockwise until the target current is achieved – as indicated by the CH B
CURRENT LEDs. Headphones can be used with the MONITOR socket to listen directly to the
loop current. NOTE: channel A output appears in the left headphone and channel B in the right.
If high frequency oscillation or low frequency hum is experienced, consult the Troubleshooting
section.
8. The loop system should now be providing a magnetic field inside the area of the loop – use the
ILR3 or field strength meter to examine its performance with respect to:
a) Magnetic field strength. This may vary across the coverage due to layout, metal loss and
loop current.
b) Frequency response. Metal losses tend to increase with frequency, and may require the
adjustment of the MLC control.
As a result of this analysis, adjust the CURRENT and set the MLC to achieve the best sound
quality. This should result in adequate magnetic field strength and a level frequency
response in order to satisfy IEC60118-4. Note: Do NOT adjust the MLC control whilst
listening to the MONITOR socket as this will not give a true indication of the response of the
actual loop.
Once the CURRENT and MLC controls have been adjusted to the correct level they should
NOT need re-adjusting.
9. If not already done so, steps can now be taken to integrate the MLD5 into a PA / mixer
arrangement following standard audio techniques. If any unusual effects are experienced refer to
the Troubleshooting section.
Note: Ideally, each input signal level should be set up to achieve 6dB (one LED) of
COMPRESSION with the quietest level of input likely to be used. This will maximize the dynamic
range of the system and ensure satisfactory performance.
10. Repeat the above procedure for each input used. When adjusting each input, make sure the
signals are removed from the other inputs. This ensures that all signals are set to equivalent
loudness and drive the compressor properly.