Contacta HLD7 User manual

1
HLD7
User Guide
April 2018
Hearing Loop Driver

2
Contents
Product Overview
Components
Connections
Suitable Cable Lengths (Metric)
Suitable Cable Lengths (Imperial)
Controls
Set-Up
Troubleshooting
Technical Specication
Standards
3
3
4-5
6
7-8
9
14-19
20-21
22
23
Contacta has a policy of continuous product development, therefore small specication changes
may not be reected in this manual. Images, labels, packaging, accessories and product colours
are subject to change without notice.

3
Product Overview
Components
Our HLD7 is a pioneering modular hearing loop driver for perimeter or
phased array congurations, designed for medium sized facilities such
as meeting rooms, lecture halls, places of worship and small theatres.
The HLD7 is a high eiciency hearing loop driver, meaning that it emits
very little heat from its compact packaging.
1
234
5
1. User Guide
2. Hearing Loop Stickers x 2
3. Rubber Feet x 4
4. Hearing Loop Driver
5. Power Supply
6. IEC Power Lead*
Cable & Equipment: A length of loop cable determined by the loop
design is also required. Hearing loop drivers also require ancillary
equipment for audio feeds, such as a microphone or sound system.
*Plug type varies by country.
6
Note: For large area hearing loop installation instructions, consult the
Large Area Hearing Loop Installation Guide.

4
1. Power Supply Input.
Power Sources - The use of unauthorised power supplies may
cause damage to the unit and may invalidate the warranty.
2. External Port - Status Indicator (Volt-free relay contacts).
3. Phantom power indication for microphone.
4. Input 1 (Microphone) - Balanced XLR with switchable 12VDC
phantom power or ¼” unbalanced TRS jack for electret
microphone with 5VDC power via 680Ω load.
5. Input 2 (Line) - Balanced XLR or ¼” TRS jack to ohmically isolated
input.
6. Expansion.
CAUTION: For connection to other Contacta systems only.
7. Feature - External monitor & control, Contacta communications
processor.
CAUTION: This is not a telecommunications port.
8. NL4 Loop Output Connection.
Connections
Rear Panel Connections:
1
2
34 5
67
8

5
Audio Connections:
2 1
3
Mic & Line
XLR connector
1: Screen/Shield
2: + (Signal Hot)
3: - (Signal Cold)
Mic
Unbalanced TRS Jack
Tip
Ring
Sleeve SOURCE
+ (Signal)
GND
Mic
Unbalanced Mono TS Jack
Tip
Sleeve SOURCE
+ (Signal)
GND
Line
Unbalanced Mono TS Jack
Tip
Sleeve
SOURCE
+ (Signal) hot
- (Signal) cold
Phantom Power
CAUTION: Route loop output cables as far away as possible from the
driver audio input cables.
Connect a twisted pair or quad core loop feeder cables to the supplied
NL4 connector (diagram below). Insert into the NL4 Loop Output
Connection on the rear of the driver.
Loop Connections:

6
Current 1A 2A 3A 4A 5A 6A
Cable Type Cable Length
Maximum
Cable
Length
Round
Cable
(CSA)
1mm2531m 266m 177m 133m 106m 89m
1.5mm2623m 311m 208m 156m 125m 104m
2.5mm2700m 350m 233m 175m 140m 117m
Flat
Cable
(Width)
10mm 394m 197m 131m 99m 79m 66m
12.5mm 746m 373m 249m 186m 149m 124m
25mm 987m 493m 329m 247m 197m 164m
Double-Turn Loop
Single-Turn Loop
The tables in this section show the metric maximum cable lengths for
dierent maximum required currents.
No clipping below 1.6kHz (IEC specications):
Example:
If an installed cable is 166m of 1.5mm² (round) single turn and
the required current noted in Step 3 (7) of Set-Up (see page 14)
is 4 amps or greater, the below table indicates that the driver
is clipping.
Suitable Cable Lengths (Metric)
Current 1A 2A 3A 4A 5A 6A
Cable Type Cable Length
Maximum
Cable
Length
Round
Cable
(CSA)
1mm2386m 193m 129m 97m 77m 64m
1.5mm2417m 209m 139m 104m 83m 70m
2.5mm2439m 219m 146m 110m 88m 73m
Flat
Cable
(Width)
10mm 345m 172m 115m 86m 69m 57m
12.5mm 533m 267m 178m 133m 107m 89m
25mm 632m 316m 211m 158m 126m 105m

7
The tables in this section show the imperial maximum cable lengths
for dierent maximum required currents.
No clipping below 1.6kHz (IEC specications):
Example:
If an installed cable is 420 feet of 18AWG (round) single turn
and the required current noted in Step 3 (7) of Set-Up (see
page 14) is 4 amps or greater, the below table indicates that
the driver is clipping.
Suitable Cable Lengths (Imperial)
Current 1A 2A 3A 4A 5A 6A
Cable Type Cable Length
Maximum
Cable
Length
Round
Cable
(AWG)
18AWG 1638ft 819ft 546ft 409ft 328ft 273ft
14AWG 2187ft 1093ft 729ft 547ft 437ft 364ft
Flat
Cable
(Width)
18AWG
(equivalent)
1843ft 921ft 614ft 461ft 369ft 307ft
14AWG
(equivalent)
2912ft 1456ft 971ft 728ft 582ft 485ft
Double-Turn Loop
Single-Turn Loop
Current 1A 2A 3A 4A 5A 6A
Cable Type Cable Length
Maximum
Cable
Length
Round
Cable
(AWG)
18AWG 1197ft 598ft 399ft 299ft 239ft 199ft
14AWG 1367ft 684ft 456ft 342ft 273ft 228ft
Flat
Cable
(Width)
18AWG
(equivalent)
1447ft 723ft 482ft 362ft 289ft 241ft
14AWG
(equivalent)
1898ft 949ft 633ft 475ft 380ft 316ft
See next page for “No clipping below 5kHz (Pro)” maximum cable lengths .

8
No clipping below 5kHz (Pro):
Example:
If an installed cable is 406 feet of 18AWG (round) single turn
and the required current noted in Step 3 (7) of Set-Up (see page
14) is 3 amps or greater, the below table indicates that the
driver is clipping.
Current 1A 2A 3A 4A 5A 6A
Cable Type Cable Length
Maximum
Cable
Length
Round
Cable
(AWG)
18AWG 718ft 359ft 239ft 180ft 144ft 120ft
14AWG 750ft 375ft 250ft 188ft 150ft 125ft
Flat
Cable
(Width)
18AWG
(equivalent)
922ft 461ft 307ft 231ft 184ft 154ft
14AWG
(equivalent)
1063ft 531ft 354ft 266ft 213ft 177ft
Double-Turn Loop
Single-Turn Loop
Current 1A 2A 3A 4A 5A 6A
Cable Type Cable Length
Maximum
Cable
Length
Round
Cable
(AWG)
18AWG 442ft 221ft 147ft 110ft 88ft 74ft
14AWG 449ft 225ft 150ft 112ft 90ft 75ft
Flat
Cable
(Width)
18AWG
(equivalent)
581ft 290ft 194ft 145ft 116ft 97ft
14AWG
(equivalent)
640ft 320ft 213ft 160ft 128ft 107ft

9
Shows MIC level Shows LINE level Shows DRIVE level
To enter adjustment mode press
both MIC + and - simultaneously
In adjustment mode the
STATUS LED will ash
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
LOW SIG
STATUS
POWER
MIC LINE DRIVE
PERIMETER
PRIMARY
SECONDARY
contacta HLD7 12 3 4 5 6
- -
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
-20DB
STATUS
POWER
MIC LINE DRIVE
PERIMETER
PRIMARY
SECONDARY
contacta HLD7 12 3 4 5 6
- -
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
-20DB
STATUS
POWER
MIC LINE DRIVE
PERIMETER
PRIMARY
SECONDARY
contacta HLD7 12 3 4 5 6
- -
Controls
Front panel overview:
Driver modes
Normal operation mode – The driver is fully functional. The controls
on the front do not change the driver operation.
Adjustment mode – In this mode one can adjust all of the levels using
the + or – buttons.
Pressing the MIC + or - will
adjust the MIC input gain;
adjustments are in 1dB steps.
LEDs show the MIC’s level
after fader
Pressing the LINE + or - will adjust the
LINE input gain; adjustments are in 1dB
steps. LEDs show the LINE level after
fader. If input is low the LOW SIG LED
will illuminate
Pressing the Drive + or - will
adjust the Drive output by
1dB steps. LEDs show the
approximate DRIVE level.
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
LOW SIG
STAT US
POWER
MICLINEDRIVE
PERIMETER
PRIMARY
SECONDARY
2.5 5 7.5 10
contacta HLD9
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
LOW SIG
STAT US
POWER
MICLINEDRIVE
PERIMETER
PRIMARY
SECONDARY
2.5 5 7.5 10
contacta HLD9
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
LOW SIG
STATUS
POWER
MIC LINE DRIVE
PERIMETER
PRIMARY
SECONDARY
contacta HLD7 12 3 4 5 6
- -
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
LOW SIG
STATUS
POWER
MIC LINE DRIVE
PERIMETER
PRIMARY
SECONDARY
contacta HLD7 12 3 4 5 6
- -
Note: Before entering a driver mode or making any changes, a loop
must be connected to the HLD7.

10
You must rst be in adjustment mode (see page 7). To enter the
engineers mode, press both Line + and - simultaneously.
Engineers mode – In this mode there are additional items that can
be adjusted, such as driver type, phantom power and high frequency
compensation.
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
LOW SIG
STAT US
POWER
MICLINEDRIVE
PERIMETER
PRIMARY
SECONDARY
2.5 5 7.5 10
contacta HLD9
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
LOW SIG
STAT US
POWER
MICLINEDRIVE
PERIMETER
PRIMARY
SECONDARY
2.5 5 7.5 10
contacta HLD9
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
-20DB
STATUS
POWER
MIC LINE DRIVE
PERIMETER
PRIMARY
SECONDARY
contacta HLD7 12 3 4 5 6
- -
There are 5 PAGE settings, each identied by a ashing MIC LED:
PAGE 1 is LED 1, PAGE 2 is LED 2, etc.
Press both Line + and - simultaneously
to enter the Engineers’ mode
CLIP
ACTIVE
PHTM
CL
IP
A
CTIVE
LOW SIG
STATUS
POWER
MIC LINE DRIVE
PERIMETER
PRIMARY
SECONDARY
contacta HLD7 12 3 4 5 6
- -

11
PAGE 1 allows you to select the driver operation; either perimeter,
primary or secondary. Always select the driver operation mode before
installing the driver in its rack mount bracket.
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
-20DB
STATUS
POWER
MIC LINE DRIVE
PERIMETER
PRIMARY
SECONDARY
contacta HLD7 12 3 4 5 6
- -
PAGE 1 is identied by
LED 1 ashing
Pressing the LINE + or - buttons
selects driver operation, Perimeter,
PRIMARY or SECONDARY
When you are ready to move
onto the next PAGE press the
DRIVE + button
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
-20DB
STATUS
POWER
MIC LINE DRIVE
PERIMETER
PRIMARY
SECONDARY
contacta HLD7 12 3 4 5 6
- -
CLIP
ACTIVE
PHTM
CL
IP
A
CTIVE
LOW SIG
STATUS
POWER
MIC LINE DRIVE
PERIMETER
PRIMARY
SECONDARY
contacta HLD7 12 3 4 5 6
- -
• PERIMETER mode, for a single loop or a double-turn loop.
• PRIMARY mode, the rst and controlling driver of two in a phased
array loop layout.
• SECONDARY mode, the second driver of two in a phased array
loop layout.
Changing the driver type
You must be in engineers mode to change the driver type.
Ensure you have selected PAGE 1.
• When only this rst light is illuminated and the driver is in the
engineers mode, press either the LINE + or – to change the driver
type from PERIMETER, PRIMARY OR SECONDARY.
• When nished setting up the driver type, press the DRIVE – button
to take the driver out of the engineers mode and put if back into
the adjustment mode. The status light will begin to ash.
• Pressing the MIC (+ and -) buttons simultaneously will take the
driver back to the normal operation mode where the controls are
non-functional.
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
LOW SIG
STAT US
POWER
MICLINEDRIVE
PERIMETER
PRIMARY
SECONDARY
2.5 5 7.5 10
contacta HLD9
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
LOW SIG
STAT US
POWER
MICLINEDRIVE
PERIMETER
PRIMARY
SECONDARY
2.5 5 7.5 10
contacta HLD9
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
LOW SIG
STAT US
POWER
MICLINEDRIVE
PERIMETER
PRIMARY
SECONDARY
2.5 5 7.5 10
contacta HLD9
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
LOW SIG
STAT US
POWER
MICLINEDRIVE
PERIMETER
PRIMARY
SECONDARY
2.5 5 7.5 10
contacta HLD9
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
LOW SIG
STAT US
POWER
MICLINEDRIVE
PERIMETER
PRIMARY
SECONDARY
2.5 5 7.5 10
contacta HLD9
The three operating modes are:
Driver Operation Selection (PAGE 1)

12
High Frequency Compensation (PAGE 2)
PAGE 2 settings are for the high frequency compensation which
is required to compensate for loss of high frequencies due to the
presence of metal within the proximity of the loop.
Microphone Phantom Power (PAGE 3)
PAGE 3 settings are for the microphone phantom power selection.
PAGE 2 is identied
by LED 2 ashing
Adjustments can be made by pressing
the LINE + or - buttons.
There are 6dB of HF compensation
adjustment possible
When you are ready to move
onto the next PAGE press the
DRIVE + button
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
-20DB
STATUS
POWER
MIC LINE DRIVE
PERIMETER
PRIMARY
SECONDARY
contacta HLD7 12 3 4 5 6
- -
PAGE 3 is identied
by LED 3 ashing
This LED indicates
that you are in the
phantom power
selection
Pressing the LINE + button turns
the phantom power on, pressing
the LINE- button turns phantom
power o
When you are ready to
move onto the next PAGE
press the DRIVE + button
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
-20DB
STATUS
POWER
MIC LINE DRIVE
PERIMETER
PRIMARY
SECONDARY
contacta HLD7 12 3 4 5 6
- -
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
LOW SIG
STATUS
POWER
MIC LINE DRIVE
PERIMETER
PRIMARY
SECONDARY
contacta HLD7 12 3 4 5 6
- -
CLIP
ACTIVE
PHTM
CL
IP
A
CTIVE
LOW SIG
STATUS
POWER
MIC LINE DRIVE
PERIMETER
PRIMARY
SECONDARY
contacta HLD7 12 3 4 5 6
- -

13
Firmware Revision Indication (PAGE 4)
THIS MODE IS DISPLAY ONLY: NO SETUP CAN BE CHANGED.
Restore to Factory Settings (PAGE 5)
PAGE 5 is for restoring settings.
PAGE 4 is identied
by LED 4 ashing
PAGE 4 rmware
revision indication
When you are ready to move onto the
next PAGE press the DRIVE + button
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
-20DB
STATUS
POWER
MIC LINE DRIVE
PERIMETER
PRIMARY
SECONDARY
contacta HLD7 12 3 4 5 6
- -
PAGE 5 is identied
by LED 5 ashing
Press the LINE + and LINE -
button simultaneously
To go back to PAGE 1
press the DRIVE + button
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
-20DB
STATUS
POWER
MIC LINE DRIVE
PERIMETER
PRIMARY
SECONDARY
contacta HLD7 12 3 4 5 6
- -
CLIP
ACTIVE
PHTM
CL
IP
A
CTIVE
LOW SIG
STATUS
POWER
MIC LINE DRIVE
PERIMETER
PRIMARY
SECONDARY
contacta HLD7 12 3 4 5 6
- -
CLIP
ACTIVE
PHTM
CL
IP
A
CTIVE
LOW SIG
STATUS
POWER
MIC LINE DRIVE
PERIMETER
PRIMARY
SECONDARY
contacta HLD7 12 3 4 5 6
- -
To exit Engineers mode press the DRIVE - button.
CLIP
ACTIVE
PHTM
CLIP
ACTIVE
LOW SIG
STAT US
POWER
MICLINEDRIVE
PERIMETER
PRIMARY
SECONDARY
2.5 5 7.5 10
contacta HLD9

14
To ensure optimal performance of an HLD7 hearing loop driver, set-up
should be performed in following order:
Step 1: Background Noise Level (see page 15)
Step 2: Metal Loss (see pages 15-16)
Step 3: Output Level and Clipping (see page 16-17)
Step 4: Field Uniformity (see page 17)
Step 5: Final Output Level Adjustment (see page 18)
Step 6: Input Signal Level Adjustment (see page 18)
Set-Up
Note:
Throughout set-up, record values on the provided Compliance
Certicate document whenever you see the following icon:
The Compliance Certicate document conrms compliance with
IEC-60118:4 if your values are within acceptable levels.
It is highly recommended that you retain a copy of the completed
Compliance Certicate document for your records and provide a copy
to the relevant facilities manager.
• TSG - Contacta Test Signal Generator (TSG1)
• FSM - Contacta Field Strength Meter (IL-CONTACTA-FSM)
• Tripod or similar for mounting the FSM is recommended
• ‘Compliance Certicate’ document
Required for Set-Up

15
Step 2: Metal Loss
1. Set up the FSM, ensuring that the two vertical arrows in the
top-right corner of the device are placed at the correct height:
• 1.2 metres (3’ 9”) for seated user.
• 1.7 metres (5’ 6”) for standing users.
A tripod or similar for mounting the FSM is recommended.
2. Connect the TSG to the line input of the HLD driver.
Step 1: Background Noise Level
This test should be performed prior to loop installation.
1. Set up the FSM, ensuring that the two vertical arrows in the
top-right corner of the device are placed at the correct height:
• 1.2 metres (3’ 9”) for seated user.
• 1.7 metres (5’ 6”) for standing users.
A tripod or similar for mounting the FSM is recommended.
2. Any lights or equipment normally active in the surrounding area
should be turned on to ensure an accurate testing environment.
3. Set the FSM to the Background Noise mode – “A-weighted”.
4. Measure and note the background noise level throughout the
looped area on the Compliance Certicate document.
5. Listen to the loop through the FSM (A-weighted) or a loop listener
(A-weighted). Note and demonstrate any interference to the
customer which may not be heard through a hearing instrument.
6. Background magnetic noise must be between -32dB and -60dB. If
the readings noted pass the Compliance Certicate document’s
requirements, move on to Step 2: Metal Loss.

16
Step 3: Output Level and Clipping
Note: This test should be performed as briey as possible.
1. Set the TSG to the 1kHz setting.
2. Set the FSM to the RMS/Peak A-Weighted mode.
3. Adjust the drive level to achieve 2 amps of output current.
4. Measure the eld strength using the FSM, and use this and
Note 1 (see page 19) to determine the extra current required.
Record the current and number of steps required, as these will be
needed again.
Note: If more than 9.0dB is required to achieve 0dB, a dierent
loop design or more powerful driver is required. This is potentially
due to metal loss.
3. Set the TSG to the 1kHz setting.
4. Set the FSM to the Third Octave F= 1000Hz setting.
5. Adjust the line level until the only the rst orange LED is turned on.
6. Adjust the drive level to achieve 2 amps of output current, as
indicated by the driver LEDs.
7. Set the TSG to the pink noise setting and record the value
measured by the FSM.
8. Set the FSM to the Third Octave F= 100Hz setting and record
the value measured.
9. Set the FSM to the Third Octave F= 5000Hz setting and
record the value measured.
10. If the dierence between the values measured at 1000Hz and
5000Hz is less than 3dB, record the results and move on to
Step 3: Output Level and Clipping. If the dierence is higher than
3dB, move on to step 11.
11. Increase the HF comp and repeat steps 3 to 10.

17
5. Use the Suitable Cable Lengths guide (see pages 6 to 8) to conrm
the installed cable length is less than the value for the current that
was recorded in Step 3: Output Level and Clipping (4).
6. If the cable length does not exceed the value recorded in Step 3:
Output Level and Clipping (4), move on to Step 4: Field Uniformity.
If the cable length exceeds the value recorded in (4), the driver is
clipping. This means the loop connected is too long; therefore:
1. The system is not IEC60118-4 compliant.
2. The sound will be distorted.
3. The driver may be susceptible to damage and warranty voided.
Perform one of the following and repeat until there is no clipping:
1. Reduce the loop current,
2. Reduce the length of the loop,
3. Use a higher diameter of cable or at copper tape,
4. Try a two-turn loop,
5. Use a higher voltage driver.
Step 4: Field Uniformity
1. Set up the FSM. Ensure that the two vertical arrows in the top-right
corner of the FSM are placed at the correct height:
• 1.2 metres (3’ 9”) for seated user.
• 1.7 metres (5’ 6”) for standing users.
A tripod or similar for mounting the FSM is recommended.
2. Reduce the loop output current to 2 amps.
3. Set the FSM to the RMS/Peak A-Weighted mode and record
the value measured by the FSM in the centre of the loop.
4. Move the FSM to other user positions within the looped area
and record the values measured by the FSM.
5. The dierences measured in other positions should not be greater
than +/- 3dB of that measured in the rst position.
6. Repeat Step 4: Field Uniformity (3 to 5) to create a suitable map of
the area looped.

18
Step 5: Final Output Level Adjustment
1. Disconnect the TSG.
2. Adjust the output current to the level recorded in Step 3: Output
Level and Clipping (4) on page 16 by pressing the DRIVE + or –
buttons; each button press alters the current by 1dB.
Example: If the measured eld strength on the FSM is (A-RMS)
-6dB (i.e. 6 presses of the + button) extra current will be required
to achieve 0dB (indicated on Note 1).
Step 6: Input Signal Level Adjustment
1. Connect the system signal source.
2. Adjust the input level (line/mic) level until the last green or rst
orange LED is lit on audio peaks.
3. The system is now set up.

19
Measured Field
Strength
Output current that
will achieve 0dB
Steps to
increase Drive
Steps to
decrease Drive
6.00dB 1.00A 6
5.00dB 1.12A 5
4.00dB 1.26A 4
3.00dB 1.42A 3
2.00dB 1.59A 2
1.00dB 1.78A 1
.00dB 2.00A 0 0
-1.00dB 2.24A 1
-2.00dB 2.52A 2
-3.00dB 2.83A 3
-4.00dB 3.17A 4
-5.00dB 3.56A 5
-6.00dB 3.99A 6
-7.00dB 4.48A 7
-8.00dB 5.02A 8
-9.00dB 5.64A 9
Note 1:
When adjusting the output current, if a level of 3 amps is reached and
yet the eld strength is still below -6dB, the correct eld strength
will not be achieved.
This is caused by either an incorrect loop design or installation, more
metal loss than expected or an incorrectly specied driver.
There is no need to go higher than +0dB ARMS.
Adjustment to drive current/level required based on the measured
eld strength:

20
Troubleshooting
Symptom Possible Fault Action
I’ve adjusted the HF comp
and see no change.
1) The driver is working close
to maximum output so there is
not enough headroom for the
HF comp to make a dierence.
1) Check loop characteristics.
If response OK at 1 amp, the
headroom is inadequate.
I start the driver and
immediately the status light
turns on.
I start the driver and the
test sequence starts, but the
status light turns on after it’s
completed.
I’ve connected the loop and
the driver doesn’t work, the
status light comes on.
My driver has been working
well for a couple weeks and
now the status light is on.
1)Loop shorted or open, too
small or too large.
2) Internal self-test failure.
1) Check loop and
connections, try known good
loop.
2) Check loop DC resistance
with an ohm meter:
0.33 ohms minimum.
The power light doesn’t
come on.
1) Mains power absent.
2) Internal failure.
1) Check mains power.
2) Seek assistance.
I can’t get my driver out of
adjustment mode.
1) Button presses not
coinciding.
2) Internal failure.
1) Press both buttons together
to exit mode.
2) As a last resort, cycle
power o/on. New settings
should have been saved.
Interference (buzzing/
whistling/hissing) is heard
through induction loop.
1) Bad input signals.
2) Internal failure.
1) Power o driver and
conrm that interference isn’t
from external origin.
2) Disconnect input signals.
If sound disappears, check
inputs.
My driver is very hot. 1) Large amount of mains hum
present on input.
2) Internal failure.
1) Check input signal source.
2) Incorrect driver being used.