Hill Audio PSM2420 User manual

USER MANUAL
PSM2420
4+2 Channel Stereo Rack Mixer
ENGLISH Page 2-11
RevA 05/2014 Order code: 12-020-0223-80200-1-01

User Manual: PSM2420 4+2 Channel Stereo Rack Mixer
V2.00 (05-2014) © Hill Audio 2
■Introduction
Dear customer,
congratulations on the purchase of this quality mixing desk. To meet your requirements,
this unit has been designed and built to the highest standards, so that we can assure
you that you have made a good and satisfying investment. To take full advantage of all
possibilities and for your own safety and the safety of your environment, please read
these operating instructions carefully before you start using the unit.
■Product description
This 4+2 Channel Stereo Rack Mixer is a stereo audio mixing console with 2
microphone inputs, 4 stereo inputs, full channel EQ’s and balanced master output and
additional subwoofer output with active crossover, which makes this unit a very
versatile choice in any environment from rental to installation.
■Security advice before use
Warning: Read this section carefully before installing, powering,
operating, cleaning or servicing this product!
The following symbols are used to identify important safety information in this manual:
DANGER!
Safety hazard. Risk
of injury or death.
WARNING!
Hazardous voltage.
Risk of severe or
fatal electric shock.
WARNING!
Fire hazard.
WARNING!
Read manual before
installation and
operation.
General advice:
1. Read this manual completely before using the product.
2. Keep this manual in your records for future reference.
3. Follow all instruction printed in this manual, otherwise warranty
may be void.
4. Follow all printed security advice on the product itself. The lighting
flash with arrowhead within an equilateral triangle makes you
aware of non-insulated AC mains voltage inside the unit. The
exclamation mark within an equilateral triangle makes you aware of
important operating and maintenance instructions in the literature
attached to this product.
5. Take care of enough distance between this product and sources of
hum and noise like electric motors and transformers.
User Manual: PSM2420 4+2 Channel Stereo Rack Mixer
V2.00 (05-2014) © Hill Audio 11
■Technical Data
Mains Input EU version…...……………………………......……………AC220-250V~ 50Hz
Mains Input US version…...……………………………......……………AC110-120V~ 60Hz
Power consumption…………………………………………………………….……max. 18W
Frequency response…………………………….……………………..20Hz-20kHz ±1.0 dBu
S/N………………………………………………………………...……………………….>77dB
THD+N………………………………………………………… ……………..< 0.07% @ 1kHz
Dimensions…...…………………..….. W 254× H178x D 104mm (85mm mounting depth)
Weight ……………………………………………………………………………………..3.2 kg
■Standards
This product complies with the following standards:
EU safety...........................................................................................EN 60065:2001 +A1
EU EMC................................................................... EN55103-1:1997, EN55103-2: 1997
US safety ………….…………..………………………………………………………UL60065
US EMC………………………..…………………………………………………..FCC Part 15
This product meets both the EMC Directive 2004/108/EC and the Low Voltage Directive
2006/95/EC.
For further information ask your dealer or visit the website of the manufacturer:

User Manual: PSM2420 4+2 Channel Stereo Rack Mixer
V2.00 (05-2014) © Hill Audio 10
properly, you will create unnecessary noise, as you first dispose of some
already existing signal level, and then later apply amplification (tainted with
noise) to make it up.
Obviously, these two requirements are marking a levelling window that the operator
must match to achieve a good sound with as little distortion and noise as possible.
DANGER: Excessive volume levels on headphones or other sound
systems may cause hearing damage. Always turn the volume control to
minimum when you switch the unit on, and do not exceed healthy
listening levels.
■Maintenance and warranty
While we have chosen the best components to make this product as rugged and
reliable as possible, some parts in audio products (potentiometers, faders, switches)
are subject to wear which is a matter of operation cycles, and not of time. While
providing a full time-based warranty according to the country’s of purchase
requirements on the function of the electronic circuitry, we hence have to limit the
warranty on such electro-mechanical parts to 90 days from the date of purchase.
In many cases, malfunction of electro-mechanical parts occurs due to dust
contamination, which may require cleaning of such parts. As the inside of such parts is
not accessible, a common practice is to use cleaning fluids in the shape of sprays.
Please be reminded that many of such fluids contain chemicals which may wash away
the dust but at the same time corrode or damage contact surface and may cause
cosmetic damage to other parts. We hence explicitly exclude any claims for exchange
of damaged part due to mechanical or chemical impact.
Without liability, we recommend CaiLube MCL fader cleaner and lubricant available
from CAIG Laboratories if the need of cleaning for electro-mechanical parts occurs.
Further to that, this unit does not need regular maintenance. The internal electronics
are protected by a 5x20mm fuse. The fuse can be accessed by the small drawer at the
AC inlet. To change the fuse, unplug the AC cord first, pull out the fuse drawer and
replace the fuse ONLY with a fuse of SAME voltage and rating. If the fuse blows again
after replacement, hand over the unit to qualified service personnel.
User Manual: PSM2420 4+2 Channel Stereo Rack Mixer
V2.00 (05-2014) © Hill Audio 3
6. Carry this product with greatest care. Punches, big forces and
heavy vibration may damage this product mechanically.
7. The manufacturer takes no responsibility for injury or damage
caused by not following the safety precautions and instructions
printed in this manual.
Protection from electric shock:
1. Only connect this unit to a mains socket outlet with protective earth
connection, ground-fault (earth-fault) protection and overload
protection.
2. Where the mains plug or an appliance coupler is used as a dis-
connect device, the disconnect device shall remain readily
operable.
3. To pull the AC Cord out of the wall outlet or the unit’s AC socket,
never pull the cable itself, but only the AC plug.
4. Disconnect the unit from AC supply by pulling the AC plug out of
the wall outlet or the unit’s AC socket before any kind of cleaning
on the product. Use smooth and dry cloth only for cleaning. Check
all connection cables before reconnecting the unit.
5. Do not expose this unit to any dripping or splashing liquids, and do
not place objects filled with liquids, such as vases, on the unit. Do
not operate this unit near to open water or in high humidity.
6. Choose the position of the AC cord according to the lowest risk of
damage by foot steps or by squeezing it. Take especially care of
the AC cord outlet on the unit as well as the AC plug and wall outlet
at the other end of the cable.
7. Do not open the unit for service purpose, as there are no user-
serviceable parts inside. Warranty will be void in any case of
unauthorized service by the user or other not authorized persons.
Protection from fire:
1. Take care of not placing the unit near sources of heat (e.g.
powerful amplifiers, fog machines).
2. Take always care of sufficient air convection in the unit’s
environment to avoid overheating, especially when mounting in a
closed environment. Make sure air convection slots – if any - are
not blocked. Do not operate this unit in environmental temperatures
exceeding 40 degrees Celsius.
3. Check the total maximum power of your AC wall outlet if you
connect several units to one wall outlet and avoid any overloading.
Protection from injury and damage:
1. Never use any accessories or modifications not authorized by the
manufacturer of this unit.
2. Choose a location for operation where the unit is protected from
vibration and where a fixed mounting position is provided.

User Manual: PSM2420 4+2 Channel Stereo Rack Mixer
V2.00 (05-2014) © Hill Audio 4
3. Before plugging the AC cord in the wall outlet, check whether the
AC mains voltage and frequency is the same as this product is
specified for. Whenever your AC plug should not match the wall
outlet, contact you dealer immediately.
4. If fluids have spilled into the unit or small parts have intruded the
unit, immediately switch off the unit and hand it over to the
authorized service for a security check.
5. Disconnect the unit from AC supply by pulling the AC plug out of
the wall outlet or the unit’s AC socket during a thunder-storm in
order to avoid any damage on the unit due to AC voltage peaks.
6. In cause of not correct function of this unit or damaged AC cord or
other damaged parts, pull immediately the AC plug out of the wall
outlet and hand the unit over to the authorized service for a
security check.
7. To meet all aspects of functionality and security during mainte-
nance work to be performed on this unit, all parts should be
replaced by genuine spare parts. Consequently, take care of your
dealer or maintenance company to be authorized by the
manufacturer.
■Health advice
This unit produces and absorbs electromagnetic radiation. The strength of radiation and
the sensitivity for disturbing interference matches the CE and FCC requirements. A
corresponding sign is printed on the backside of the unit. Any change or modification
may affect the behavior of the unit concerning electromagnetic radiation, with the CE
requirements eventually not to be met any more. The manufacturer takes no
responsibility in this case.
■Functional advice
This unit is immune to the presence of electromagnetic disturbances – both conducted
and radiated - up to a certain level. Under peak conditions, the unit is classified to show
a “class C” performance criteria and may encounter temporary degradation or loss of
function which may need manual help to recover. In such case, disconnect the AC
power from the unit and reconnect it again to recover.
■Environmental advice
This unit is build to conform to the ROHS standards and the WEEE
directive 2002/96/EC of the European Parliament and of the Council of
the European Union. Under these regulations, the product shall not be
discarded into regular garbage at the end of its life, but shall be returned
to authorized recycling stations.
User Manual: PSM2420 4+2 Channel Stereo Rack Mixer
V2.00 (05-2014) © Hill Audio 9
For making audio signal connections, always remember that good and reliable
connections are a basic requirement for good sound and reliable operation. Bad
soldering of cables can result in intermittent audio signals or temporarily lost ground
connections, hence always use good cables. In case of doubt about making proper
connections, please see check the standard pin assignments required for proper
operation in the appendix of this manual.
It is also essential that high-gain inputs are terminated properly to avoid excess noise
contribution. Specifically, this applies to the PHONO inputs. If these inputs are not used
and the sensitivity is switched to “PHONO”, the inputs shall be terminated with the
supplied termination plugs (as factory-inserted at delivery).
■Powering up
Following a proper power-up sequence protects your equipment – specifically speakers
– and your ears. Follow the below procedure:
Turn down all output volume controls of any equipment in your audio system.
Switch on your audio sources first (Turntables, CD Players, PC’s with
soundcards, Tapedecks, etc.)
Switch on the audio mixer
Switch on any audio processor between the mixer and the amplifier(s) [if any].
Switch on the amplifier(s).
Turn up the audio level on your sources if such controls are provided.
Set the audio output of your mixer to a low level.
Set the audio output of any audio processor between the mixer and the
amplifier(s) to a medium level [if any such processors].
Turn up the volume controls of your amplifier(s) slowly.
Make adjustments to all volume settings as needed.
For switching off, follow the inverse sequence – always switch off your amplifier(s) first,
then any processors between mixer and amplifier(s), then the mixer, then the sources.
■Operation
Apart from using good equipment, good sound comes from using it correctly. Level
setting mistakes are one of the common reasons why even good equipment may not
perform as desired. For setting levels, please be reminded that two guidelines need to
be followed:
Avoid distortion by leaving some headroom. Never overrun any audio-
equipment’s inputs. Level meters and displays allow you to make sure that
signals do not enter critical levels.
Avoid unnecessary amplification by using as little attenuation as possible. For
example, if you turn down the input gain of a mixer to minimum, and then
increase the main output of the mixer to maximum to drive your amplifier

User Manual: PSM2420 4+2 Channel Stereo Rack Mixer
V2.00 (05-2014) © Hill Audio 8
27. Crossfader. A high-grade dual rail 45mm fader determines the mix ratio
between the stereo signals routed to A (assigned to the left crossfader side)
and B (assigned to the right crossfader side). If no signals are assigned by
means of the switches (26), the crossfader is disabled.
28. Crossfader Curve switch. Allows the transition characteristic of the crossfader
between the A and B signal to be switches between smooth a flat and steep
mixing curve.
29. AUX Input for INPUT4. This is a 3.5mm Mini-TRS stereo socket which allows
to connect sources like MP3 players etc. without removing the mixer from its
mounting position.
30. POWER LED. Indicates whether the unit is switched on or off.
31. Output level meter. Displays the output level at outputs (4) and (5).
32. Main 1 level control. Determines the main output level present at outputs (4)
and (5).
33. Main 2 level control. Determines the output level present at output (9).
34. Talkover control. This control allows to set the amount of damping applied to
the stereo music signal when speaking into a microphone connected to either
the MIC1 or MIC2 input. The threshold level from which on this damping is
activated is set by the rear panel control (16).
35. PFL volume. Determines the signal volume at the headphone output (38).
Always set this control to minimum before putting on headphones, as sudden
high-volume impact may damage your ears. See further health advice below.
36. PFL Mix control. If the PFL mode (37) is set to “BLEND”, the headphone
signal can be a mix of the main output and the input(s) assigned to the PFL
bus by means of switches (25). This control determines the mix ratio between
the main and the PFL signal.
37. PFL Mode switch. This control offers two pre-listening modes: (A) Split. In this
mode, the master signal appears on one earcup of the headphones, the PFL
signal on the other earcup. (B) Blend. In this mode, main and PFL signal are
mixed with adjustable ratio by means of control (36). A LED indicates the
pressed position.
38. Headphones output. A ¼” TRS connector to connect a headphone. Turn the
PFL volume (35) down before plugging in any headphones.
■Connections
For connecting this unit to AC mains, please note:
Check whether the AC mains voltage and frequency is the same as this
product is specified for (see rear panel of product). Whenever the specified
voltage or your AC plug should not match the local conditions, do NOT plug
the AC cord into the wall outlet and contact you dealer immediately.
Do not operate this unit without the line cord earth ground connected. To do
so may increase the risk of electric shock and increase line cord conducted
emissions.
User Manual: PSM2420 4+2 Channel Stereo Rack Mixer
V2.00 (05-2014) © Hill Audio 5
■Unpacking
Please check that the box contains the following items:
Main parts: 1 pcs. Main unit
1 pcs. Mains cable
1 pcs. Operation manual
If any part is missing, please contact your dealer immediately for replacement.
Warning: After unpacking, and before plugging the AC cord in the wall
outlet, check whether the AC mains voltage and frequency is the same
as this product is specified for (see rear panel of product). Whenever
the specified voltage or your AC plug should not match the local
conditions, do NOT plug the AC cord into the wall outlet and contact
you dealer immediately.
■Back Panel
1. AC inlet and fuse holder. Use the supplied AC cord to connect the unit to AC
mains. Make sure voltage and frequency stated on the unit comply with your
local AC supply. The fuse can be accessed by the small drawer at the AC
inlet. To change the fuse, unplug the AC cord first, pull out the fuse drawer
and replace the fuse ONLY with a fuse of SAME voltage and rating. If the fuse
blows again after replacement, hand over the unit to qualified service
personnel.
2. Power switch. Switches the unit on and off. Make sure to switch the unit off
when not in use.
3. AC Voltage selector switch. Make sure this is set to the local AC supply
voltage. Unplug unit before making any changes.

User Manual: PSM2420 4+2 Channel Stereo Rack Mixer
V2.00 (05-2014) © Hill Audio 6
4. Main 1 stereo output. This is a balanced stereo output carrying the main
output signal controlled by (32).
5. Main 1 stereo output. This is an unbalanced output carrying the same signal
as output (4).
6. Subwoofer output. This is a balanced mono output for connecting an amplifier
driving a subwoofer system. Please note that the subwoofer output runs in
parallel to the Main 1 output, hence while the subwoofer upper frequency limit
can be adjusted by means of control (7), no lower frequency limit is introduced
to the Main 1 output (4&5).
7. Crossover frequency adjustment of internal active crossover. Together with
the level control (8), this allows to set the upper frequency limit of the
subwoofer output (6). Choosing an appropriate crossover frequency will avoid
unpleasant interference effects with your main program speakers. Check your
subwoofer system specification to determine a suitable frequency.
8. Level control for subwoofer output (6).
9. Main 2 stereo output. This is an unbalanced output carrying the Main 2 signal
controlled by (33). This output can be used for a 2nd zone which needs
independent volume control, such as the DJ booth or the seating area of a
club.
10. Record output. This is an unbalanced stereo output carrying the same signal
as the Main 1 output (4/5), but not influenced by the main volume control (32).
This is normally used for recording the output to an external tape, CD or
memory device.
11. Phono Inputs. Depending on the position of the selector switches (13), these
RCA connectors provide the following inputs: (A) Position “PHONO”: input for
phono-level signals to the assigned channels, featuring the necessary RIAA
equalization. (B) Position “LINE”: input for line-level signals to the assigned
channels. Note that if the Phono inputs are not used and the sensitivity is
switched to “PHONO”, the inputs shall be terminated with the supplied
termination plugs (as factory-inserted at delivery).
12. Line inputs. These RCA connectors provide inputs for line-level signals to the
assigned channels.
13. PHONO/LINE selector switches for PHONO inputs. These switches change
the sensitivity of the PHONO inputs between PHONO (RIAA equalized) and
LINE level.
14. Microphone input for MIC1. This is a balanced XLR & ¼” TRS Combo
connector without phantom power provision, hence only suitable for dynamic
microphones.
15. Microphone input for MIC2. A ¼” TRS socket without phantom power
provision for microphone 2.
16. Talkover threshold control. The setting of this control determines at which
microphone level the automatic talkover starts to reduce the master output
level. In addition, the amount of reduction can be determined with the top
panel TALKOVER control (34).
User Manual: PSM2420 4+2 Channel Stereo Rack Mixer
V2.00 (05-2014) © Hill Audio 7
■Top Panel
17. Microphone equalizer. Allows the adjustment of the tonal balance for each of
the two microphone inputs in three voice-specific frequency bands with an
adjustment range of ±12dB.
18. Microphone level control. Sets the microphone level, provided that the
microphone(s) is/are switched on by means of switch(es) (18).
19. On/Off (ON AIR) switches for microphone channels.
20. Input selector for stereo channels. Switches between the inputs as indicated
on the front panel. A LED indicates the pressed position.
21. Gain control of input channels. Allows adjustment of the input sensitivity to
compensate for different source volumes.
22. 0dB LED. Facilitates proper setting of input gain levels. The LED lights up
when the signal after the Gain control (21) reaches 0dB.
23. Stereo channel equalizer. Allows the adjustment of the tonal balance for each
of the stereo inputs in three music-specific frequency bands with an
adjustment range of -26/+12dB, thus providing a virtual “kill” function for each
frequency band if set to extreme attenuation.
24. Channel fader for input channels. A high-grade dual rail 60mm fader
determines the volume of the respective channel.
25. PFL switch for stereo channels. Assigns the respective channel to the
headphone bus for pre-fader-listening (PFL). A LED indicates the pressed
position.
26. Crossfader assignment switch. Allows to route the respective channel either to
A (left crossfader side) or to B (right crossfader side) or directly to the master.