Ashly MX-508 User manual

MX-508
Stereo
Microphone/Line
Mixer
Operating Manual

2
Operating Manual -MX-508 Stereo Microphone/Line Mixer
Table Of Contents
1 INTRODUCTION 3
2 UNPACKING 3
3 ACPOWERREQUIREMENTS 3
4 CONTROLS 4
5 CONNECTIONSANDCABLES 6
6 CHANGINGFACTORYCONFIGURATIONS 8
61 Changing the Aux Pre/Post Assignment                                       8
7 TYPICALAPPLICATIONS 8
71 Small Sound Reinforcement System8
72 Meeting Room, Board Room, Church, etc Using Remote Control                  8
73 Location Recording or Broadcast Mixing                                     8
74 Submixer In Larger Sound System8
8 TROUBLESHOOTINGTIPS 9
81 No Sound9
82 Distorted Sound9
83 Excessive Noise9
84 Excessive Hum 9
9 SPECIFICATIONS 10
10 WARRANTYINFORMATION 10

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Operating Manual - MX-508 Stereo Microphone/Line Mixer
1.INTRODUCTION
Congratulations on your purchase of an Ashly MX-
508 stereo mixer In one compact rack-mount package we
have combined features, reliability, and sonic performance
found only in larger and more expensive mixing consoles
This third generation mixer utilizes a universal 100-240VAC
switching power supply, and adds a 35mm front panel stereo
line input jack
Other features include output mute switches, dual jack
insert points, switchable +48V phantom power, and front
panel switching on each channel selecting between mic or
line input Three-band equalization with a fixed frequency
low and high shelf and a tunable mid-range control provides
perfect true-reciprocal equalization curves A concentric level
and pan control combined with a concentric pair of auxiliary
sends complete each input channel
Ultra low-noise summing amplifiers combine the
channel signals for the main and send outputs Two 10-segment
LED arrays monitor main or aux outputs Standard line level
outputs on 1/4" connectors, stereo pre-fader line outputs on
RCA connectors, and transformer isolated 600 ohm outputs on
XLR connectors are provided as standard equipment Ashly
still uses professional quality 16mm metal shaft potentiometers
on all controls for greater accuracy and long life
2.UNPACKING
As a part of our system of quality control, every Ashly
product is carefully inspected before leaving the factory to
ensure flawless appearance After unpacking, please inspect
for any physical damage Save the shipping carton and all
packing materials , as they were carefully designed to reduce
to minimum the possibility of transportation damage should
the unit again require packing and shipping In the event that
damage has occurred, immediately notify your dealer so that
a written claim to cover the damages can be initiated
The right to any claim against a public carrier can be
forfeited if the carrier is not notified promptly and if the
shipping carton and packing materials are not available for
inspection by the carrier Save all packing materials until the
claim has been settled
3.ACPOWERREQUIREMENTS
The MX-508 mixer will perform normally from 100
to 240 volts AC, 50-60Hz Use only properly grounded
AC receptacles To reduce the risk of ground loop hum, use
a central point for system AC power distribution Power
consumption is less than 50 watts
WARNING:
THIS APPARATUS MUST BE EARTHED
The exclamation point within an eqilateral
triangle is intended to alert the user to
the presence of important operating and
maintenance instructions in the literature
accompanying the device.
The lightning flash with arrowhead
symbol, within an equilateral triangle, is
intended to alert the user to the presence
of uninsulated "dangerous voltage" within
the product's enclosure that may be of
sufcient magnitude to constitute a risk
of electric shock to persons.
TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT RE-
MOVE COVER. NO USER SERVICEABLE PARTS INSIDE.
REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
TO REDUCE THE RISK OF FIRE OR ELECTRICAL SHOCK,
DO NOT EXPOSE THIS APPlIANCE TO RAIN OR MOISTURE.
TO REDUCE THE RISK OF FIRE, REPLACE ONLY WITH
SAME TYPE FUSE. REFER REPLACEMENT TO QUALI-
FIED SERVICE PERSONNEL.

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Operating Manual -MX-508 Stereo Microphone/Line Mixer
4.CONTROLS
41 Input Level (Gain)
This control sets the operating level of the Microphone
preamp and Line Input Best signal to noise ratio is obtained
with higher gain settings It is therefore desirable to set the
Gain control as high as possible while still leaving enough
headroom (typically 20dB) to prevent distortion
42 Mic-Line Switch
This switch selects between the XLR microphone input
or the 1/4" line input jack as the signal source It can also serve
as a "channel mute" switch when selected to the unused input
43 Channel Clip Indicator
This peak sensitive indicator monitors all level critical
points in the input channel and illuminates if any of them reach
levels 3 dB below clipping
44 Equalization
Channel EQ consists of a high shelf control at 15KHz
(middle of shelf), a sweepable mid control, and a 70Hz low
shelf control The mid control is sweepable from 140Hz to
8KHz with a bandwidth of approximately 1 octave
45 Aux Sends
These are an additional pair of level controls to adjust the
feed to monitors or effects units Aux 1 is factory preset to pre-
fader, pre-EQ, while Aux 2 is post-fader, post-EQ Both Aux
sends can be internally switched to pre or post fader/EQ Note:
See section on changing factory configurations.
46 Level and Pan
This concentric pair of controls adjusts the level and
stereo position of the channel
47 Aux Master Sends
These two controls adjust the overall gain of the output
stages for the Aux 1 and Aux 2 Send outputs
48 Aux Master Returns With Pan
These two concentric level and pan controls adjust the
returning signal from effects units or auxiliary inputs to the
Main Left and Right outputs Return 1 is stereo and return 2
is mono If only the right connection to return 1 is made, this
return will function as mono with pan
49 Stereo Line In and Aux 1 Send
This control adjusts the back panel RCA and front
panel 35mm Stereo Line In level to the Main Stereo
outputs The RCA and 35mm input jacks are electronically
buffered and then summed together The outer concentric
control labeled "To Aux 1" sums the left and right Stereo
Line inputs to a mono signal and then applies it to the Aux 1
Master group for use with monitors or effects It is "pre-
fader", or independent of the stereo level control

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Operating Manual - MX-508 Stereo Microphone/Line Mixer
410 Output Meters
A pair of peak reading 10 segment LED meters
are used to indicate output level Green LED's are used
below 0 VU, yellow above 0 VU and red LED's indicate
clipping 0 VU is equivalent to +4 dBu (1228Vrms)
This meter pair is switchable (with the headphone output)
to either the Main Left and Right outputs or the Aux 1
and 2 outputs The red clip LED's will illuminate if the
summing amplifiers are clipping even if the main output
controls are off, in which case one or more inputs must
be turned down Note: The output meters are accurately
calibrated to the transformerless output levels, but not
necessarily the transformer-balanced outputs. See note
on Transformer Balanced Outputs.
411 Main Output Level
These controls determine the level of both
transformer balanced and transformerless output stages
for the Main Left and Right outputs
412 Main Output Mutes
These switches turn off both the transformer-
balanced outputs as well as the transformerless 1/4"
stereo outputs, and indicate the mute mode by lighting the
red LED near the switch The headphone and metering
functions continue uninterrupted even though there is no
signal on the mixer's main outputs.
413 Phantom Power Switch
This front panel switch enables the 48 Volt phantom
power supply for condenser microphones which can use this
feature One switch controls all the inputs If you have a mix
of condenser and dynamic microphones, the phantom power
will not affect the operation of the dynamic mics
414 Mono Output Level
This control adjusts the level of the summed mono
output It is completely independent of the Main Left and
Right masters
415 Headphones Level
This control adjusts the level of the designated output
signal (Mains or Aux) to the headphone jack
416 Meter/Phones Select
This switch selects either the Main Left/Right outputs or
the Aux 1/Aux 2 outputs to the LED meters and the headphone
jack
417 Headphone Output
This front panel 1/4" TRS connector feeds a standard
set of stereo headphones A selector switch that also controls
the level meter allows monitoring the main or Aux outputs

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Operating Manual -MX-508 Stereo Microphone/Line Mixer
5.CONNECTIONSANDCABLES
The MX-508 mixer is fitted with five types of audio
connectors: 3-pin XLR type male (stereo outputs), 3-pin XLR
type female (mic inputs), tip-ring-sleeve (TRS) phone jack,
35mm TRS phone jack (front panel stereo line in), and RCA
jack Certain 1/4" jack connections use an unbalanced mono
plug, which is also shown
Two-conductor (twisted pair) shielded cable is best for
all XLR type connections Belden No 8412, or its equivalent,
is an excellent cable due to its heavy construction This type
of cable should be used for all portable applications Snake
cables containing multiple shielded pairs must be handled very
carefully because the leads tend to be fragile, and a broken
conductor is difficult to repair
If low level and high level lines (eg, microphones and
mixer line outputs), or if either of these lines and speaker cables
are run parallel for long distances, crosstalk may be significant
In fact, the crosstalk (signal leakage between cables) can cause
an electronic feedback loop, oscillation, and possibly damage
to the equipment To minimize crosstalk, physically separate
low level (microphone) cables from speaker cables by the
greatest feasible distance At any point where cables meet,
run low level cables perpendicular to high level or speaker
cables If low and high level or speaker cables must be run
parallel and in close proximity to one another, they should be
bundled separately
51 Microphone Input
The microphone input is an active
balanced type with a nominal impedance
of 1200 ohms Its noise performance
is best with a 200 ohm microphone A
plug-in transformer option is available
if you need the isolation The Mic input
connector is a standard 3-pin XLR female
with the shield on pin 1, the (+) in-phase
connection on pin 2, and the (-) out-of-
phase connection on pin 3
52 Input Pad
The Pad is a 20dB attenuation
switch on the rear panel for use with the
XLR microphone input It has no effect
on the line input It should normally be
left in the "out" position for best signal to
noise ratio and should only be used when
the input is being overdriven with the Gain
control at its minimum setting
53 Line Input
The line input is a standard 1/4"
TRS active balanced connection, with a
balanced input impedance of 20KΩ It will accommodate a wide
range of input levels
54 Channel Send And Return Patch
A channel patch point allows a device such as graphic
equalizer, noise gate, compressor/limiter, remote level controller,
or direct out recording device to be used on individual channels
The MX-508 has separate send and return jacks, both using
balanced signals for low noise Use the send jack to feed the input
of the device to be inserted, and use the return jack for the output
of the inserted device Single jack TRS insert is not available
If using the send jack as a Direct Line Output (pre EQ),
use either a standard mono plug (tip-sleeve) or stereo (tip-ring-
sleeve) The TRS plug gives the best noise performance into a
balanced input

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Operating Manual - MX-508 Stereo Microphone/Line Mixer
55 Aux Send Outputs
The Aux Outputs are used to drive monitors, effects
processors, recording devices, or any function which requires
isolated level control from the main outputs They are pseudo-
balanced 1/4" tip-ring-sleeve
56 Aux Return Inputs
The return inputs are 1/4" unbalanced Return 1 is stereo
with a left and right input, while Return 2 is mono To use
return 1 as mono, connect only to the Right return 1 input
57 Stereo Line In - Stereo Line Out
The stereo line inputs on RCA connectors (and the
35mm front panel jack) have a nominal operating level of
-10dBu to match most consumer audio players The stereo
line outputs are -10dBu "pre-master", so they are not affected
by the settings of the Main output controls
58 Transformer Balanced Outputs
The transformer outputs use male XLR type connectors
and provide total isolation for 600 ohm lines Pin 1 is ground,
pin 2 is (+), and pin 3 is (-) These outputs are controlled by
the Left and Right Master levels, with a nominal operating
level of +4dBu
Note: The transformer-balanced outputs are designed
to drive up to +24dBu into 600 ohm loads. Because of the
nature of an output transformer, the output level increases
as the impedance of the terminating load becomes higher
than 600 ohms. Whereas a "direct-coupled" output stage
like that of the transformerless outputs will not change as
the load changes, any transformer used in an audio path
is affected by its termination impedance. Since line level
inputs on audio devices are typically 10KΩ or higher, expect
a slight increase (2.5dB) in output level when driving high
impedance inputs with the transformer outputs. The output
meters will remain accurately calibrated to the levels present
on the transformerless outputs, regardless of the load on the
transformer outputs.
59 Transformerless Outputs
These outputs are also controlled by the left and right
master They are 1/4" servo-balanced TRS jacks with a
nominal operating level of +4dBu into any load
510 Sub Outputs
These outputs are generally used to feed another
mixer's Sub Inputs for expanded input capacity The Main
left and right submaster outputs use unbalanced (mono)
1/4" connectors The Aux submaster outputs use 1/4" TRS
connectors with Aux 1 on the tip and Aux 2 on the ring
511 Mono Output
This output is a function of the Mono Level Control,
which is a pre-Master summed output from the left and right
mix busses Like the main outputs, it is pseudo-balanced with
a nominal level of +4dBu
512 Sub Inputs
These inputs are useful for linking together two or more
mixers for expanded input capacity, and include Main left,
Main right, and Aux 1/Aux 2 Signal to the Sub Inputs is taken
from the Sub Outputs of another mixer, with a nominal level
of +4dBu The Aux submaster input requires Aux 1 on the tip
and Aux 2 on the ring

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Operating Manual -MX-508 Stereo Microphone/Line Mixer
6.CHANGINGFACTORYCONFIGURATIONS
61 Changing the Aux Pre/Post Assignment
The MX-508 is shipped from the factory with Aux 1 assigned Pre-Fader/EQ, and Aux 2 Post-Fader/EQ Each channel's
Aux Send controls may be independently configured for either pre or post fader/EQ operation with a minimum of tools and no
soldering To make this change, refer the following procedure to a qualified service technician:
Unplug the unit's AC power cord from the outlet Remove the bottom cover which is fastened by seven 6-32 screws
Locate the 3 pin headers labeled Send 1 and Send 2 near the front of each input channel circuit board (see diagram) Remove
the shunt bar from the factory installed position indicated on the circuit board legend and place the shunt on the other position
of the 3 pin header
7.TYPICALAPPLICATIONS
The following information will help you make the most of your new mixer:
SmallSoundReinforcementSystem
The MX-508 can be used to mix typical sound sources that might be found in a small club, school theater or similar
environment Six of the input channels are used for microphones for live vocal or instrumental pickup The remaining two
channels are used for playback from a stereo source, such as might be used during intermission, for backup, for special recorded
effects, etc Power amplifier(s) (or any additional outboard equipment) is fed from the transformer balanced Output connectors
MeetingRoomorChurchUsingRemoteControl
The MX-508 can be interfaced with an Ashly VCM-88C eight channel remote level controller, allowing a full-featured
mixer to be operated from a distance by a non-technical person Once initially set up, the RD-8C desktop remote controller
can be located far away from the main audio equipment rack using a single balanced XLR cable, allowing for simplified sound
system operation using a limited number of knobs, lights, and buttons
LocationRecordingorBroadcastMixing
The MX-508 can be used to mix sources typically found in location recording or broadcast situations (mostly microphones)
The Stereo Line Out jacks can feed a portable recorder, and the recorder’s line output is brought back to the Stereo Line In
connectors for monitoring For live remote broadcast applications the Mono Out connector can feed a suitable TELCO or
internet interface
SubmixerInLargerSoundSystem:
The MX-508 can be used to provide a drum mix to the main mixer without tying channels on the main console Up to eight
mics can be “pre-mixed” in stereo, with all drum-specific gating, compression, and effects controlled directly by the drummer
Either the main OUTPUT or the SUB OUT connectors can be used to feed the mixed drum signal to the main mixer If there
is significant distance between the MX-508 and the “master” mixer, use the balanced or transformer- balanced Main outputs
for long cable runs

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Operating Manual - MX-508 Stereo Microphone/Line Mixer
8.TROUBLESHOOTINGTIPS
81 No Sound
Check the AC power Is the power switch LED on and illuminated? Check the level meters If they are operating, either
the problem is between the mixer and the later components in the system, or else the Output Mute switches are pressed If there
is no meter activity, check to see you really have an input signal and that it is on the desired channel, or check to see that the
meter select switch is set to Left/Right Check that you have the master gain controls at the desired operating level and that the
output mute switches are out
82 Distorted Sound
Something is being overdriven in the signal path If the clip indicators are active, reduce the channel gain controls and/
or press in the pad switch on the rear panel If the level meters are constantly in the red, reduce the Master gain and increase
the gain of components following the mixer There are many gain adjustments in the mixer itself and probably several others
in other system components which makes it possible to overdrive an input section and then incorrectly try to reduce the gain of
the output section The best way to approach setting gains is to establish the operating level of input stages first by setting their
gain as high as possible but leaving about 20dB of headroom for loud peaks, then move on to set the master gain to produce a
good meter reading Proceed to set the gain of equalizers, limiters, crossovers, and amplifiers following the mixer in the same
manner, always working toward the later stages of the system
83 Excessive Noise
If the noise is in the form of hiss, the problem is usually due to an input stage set up for low gain and then compensating
by increasing the master gain Check that the Pad switch is not enabled unnecessarily Turn up the channel gain controls and
reduce the master gain
84 Excessive hum
This is usually caused by "ground loops" in the system wiring A complex sound system with many sources separated
by significant distance and using several power outlets has many opportunities for this problem to occur If possible, feed
everything in the system from one power source with a common ground Use balanced input and output connections between
widely separated components
If you need help, get in touch with your Ashly dealer or call an Ashly technical service representative at 1-800-828-6308

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Operating Manual -MX-508 Stereo Microphone/Line Mixer
9.SPECIFICATIONS
DISTORTION
THD at +4 dBu output, 20Hz-20KHz                  <005%
THD at +20dBu output, 30Hz-10KHz                 <005%
IMD (SMPTE) at +20dBu output                     <005%
HUM&NOISE(20Hz-20KHzatmaxpreampgain)
equivalent input hum and noise                    <-128dBu
residual output noise, TRS outputs,
all levels at minimum                            <-100dBu
residual output noise, XLR outputs,                  <-90dBu
Master Level at nominal,
all Ch Level controls at min                        <-80dBu
Master Level and one Ch Level at nom              <-68dBu
Aux 1 or 2 Out, Aux Master at nominal
and all Ch Aux at min,                            <-88dBu
Aux 1 or 2 Out, Aux Master and
one Ch Aux at nom<-68dBu
MAXIMUMVOLTAGEGAIN(±2dB)
MASTER
Mic Input to Master Output, 600 ohm load                84dB
Line Input to Master Output, 600 ohm load               30dB
AUX SENDS
Mic Input to Aux Master Output, pre ch level             80dB
Mic Input to Aux Master 2 Output, post ch level           95dB
SUB Input to Master Output                           12dB
AUX RETURNS 1 or 2 to Master Output                 30dB
Stereo Line In to Master Output                        27dB
FREQUENCYRESPONSE
20Hz-20KHz +05/-10dB
50Hz-10KHz +0/-05dB
EQUALIZATION
Low                          ±12dB at 70Hz, shelving
Mid                      ±12dB peaking, 140Hz-8KHz
High                         ±12dB at 15KHz, shelving
CROSSTALK
adjacent inputs, 20Hz-20KHz                       <-65dB
Mic Input to Master Output, 1KHz                    <-65dB
Mic Input to Master Output, 20KHz                   <-55dB
VUMETERS
Selectable to Main or Aux Outputs              0VU = +4dBu
-21 VU to +6 VU
PEAKINDICATORS
Peak Clip indicator on each input channel and left and right outputs,
illuminates 3dB below clipping
PHANTOMPOWER
+48 VDC applied to all Mic Inputs, switchable on front panel
Maximum total current draw = 80mA Maximum single channel
current draw = 14mA Gradual power-up and down to eliminate
"pops"
SHIPPINGWEIGHT
18 lbs (82kg)
DIMENSIONS
19" x 525" x 94" (483mm x 133mm x 239mm)
POWERREQUIREMENTS
100-240 VAC, 50-60 Hz, 30 watts
*unless otherwise stated, specification conditions are: 150Ω
source, maximum preamp gain, all other controls set at
nominal, XLR outputs into 600Ω or greater.

11
Operating Manual - MX-508 Stereo Microphone/Line Mixer
10.AshlyAudioInc.LIMITEDWARRANTY(USAONLY)
(Othercountriespleasecontactyourrespectivedistributorordealer.)
For units purchased in the USA, warranty service for this unit shall be provided by ASHLY AUDIO, INC in accordance
with the following warranty statement
ASHLY AUDIO, INC warrants to the owner of this product that it will be free from defects in workmanship and materials
for a period of FIVE years from the original-date-of-purchase ASHLY AUDIO INC will without charge, repair or replace at its
discretion, any defective product or component parts upon prepaid delivery of the product to the ASHLY AUDIO, INC factory
service department, accompanied with a proof of original-date-of-purchase in the form of a valid sales receipt This warranty
gives you specific legal rights, and you may also have other rights, which vary from state to state
EXCLUSIONS: This warranty does not apply in the event of misuse, neglect, or as a result of unauthorized alterations or
repairs made to the product This warranty is void if the serial number is altered, defaced, or removed ASHLY AUDIO, INC
reserves the right to make changes in design, or make additions to, or improvements upon, this product without any obligation
to install the same on products previously manufactured
Any implied warranties, which may arise under the operation of state law, shall be effective only for FIVE years from the
original-date-of-purchase of the product ASHLY AUDIO, INC shall be obligated to only correct defects in the product itself
ASHLY AUDIO, INC is not liable for any damage or injury, which may result from, or be incidental to, or a consequence of,
such defects Some states do not allow limitations on how long an implied warranty lasts, or the exclusion, or limitation of
incidental or consequential damages, so the above limitations or exclusions may not apply to you
OBTAININGWARRANTYSERVICE:
For warranty service in the United States, please follow this procedure:
1) Return the product to ASHLY AUDIO, INC freight prepaid, with a written statement describing the defect and
application that the product is used in ASHLY AUDIO, INC will examine the product and perform any necessary service,
including replacement of defective parts, at no further cost to you
2) Ship your product to:
ASHLY AUDIO, INC
Attention: Service Department
847 Holt Road
Webster, NY 14580-9103

Printed in USA MX508 R0111
ASHLY AUDIO INC. 847 Holt Road Webster, NY 14580-9103
Phone: [phone] Fax: [phone]
Toll Free [phone] Internet: www.ashly.com
 2011 by Ashly Audio Corporation. All rights reserved worldwide.
Operating Manual - MX-508 Stereo Microphone/Line Mixer