LX-308B
Stereo Line Mixer
Operating Manual
Ashly Audio Inc.
847 Holt Road, Webster, NY 14580-9103
Toll Free (800) 828-6308, Telephone (585) 872-0010, FAX (585) 872-0739
www.ashly.com
All Trademarks referred to herein, are the property of their respective owners. R-042707
All Rights Reserved
Page - 2
Operator Manual – LX-308B Mixer
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Copyright© 2007 – Ashly Audio Inc.
Operator Manual – LX-308B Mixer
Page - 3
Important Safety Instructions
Consignes de sécurité à lire attentivement
Safety Instructions – 3
Introduction - 4
LX-308B Mixer – 5
Connectors & Cables – 5
Physical Description - 6
Installation – 7
Typical Applications - 8
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 sufficient magnitude to constitute a
risk of electric shock to persons. The exclamation point within an equilateral
triangle is intended to alert the user to the presence of important operating and
maintenance instructions in the literature accompanying the device.
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Read these instructions.
Keep these instructions.
Heed all warnings.
Follow all instructions.
To reduce the risk of fire or electric shock, do not expose
this apparatus to rain or moisture.
Do not use this apparatus near water.
Clean only with dry cloth.
Do not block any ventilation openings. Install in
accordance with the manufacturer’s instructions.
Do not install near any heat sources such as radiators, heat
registers, stoves, or other apparatus (including amplifiers)
that produce heat.
Do not defeat the safety purpose of the polarized or
grounding-type plug. A polarized plug has two blades
with one wider than the other. A grounding type plug has
two blades and a third grounding prong. The wide blade
or the third prong are provided for your safety. If the
provided plug does not fit into your outlet, consult an
electrician for replacement of the obsolete outlet.
Protect the power cord from being walked on or pinched
particularly at plugs, convenience receptacles, and the
point where they exit from the apparatus.
Only use attachments/accessories specified by the
manufacturer.
Use only with the cart, stand, tripod, bracket, or table
specified by the manufacturer, or sold with the
apparatus. When a cart is used, use caution when
moving the cart/apparatus combination to avoid injury
from tip-over.
Unplug this apparatus during lightning storms or when
unused for long periods of time.
Refer all servicing to qualified service personnel.
Servicing is required when the apparatus has been
damaged in any way, such as power-supply cord or plug
is damaged, liquid has been spilled or objects have fallen
into the apparatus, the apparatus has been exposed to
rain or moisture, does not operate normally, or has been
dropped.
Le symbole de la flèche dans un triangle équilateral symbolisant la foudre est
prévu pour sensibiliser l’utilisateur à la présence de tension de voltage non isolée
à l’intérieur de l’appareil. Elle pourrait constituer un danger de risque de
décharge électrique pour les utilisateurs. Le point d’exclamation dans le triangle
équilatérale alerte l’utilisateur de la présence de consignes qu’il doit d’abord
consulter avant d’utiliser l’appareil.
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Lisez ces instructions.
Conservez ces instructions.
Observez les avertissements.
Suivez ces instructions.
Pour réduire le risque de feu ou la décharge électrique,
ne pas exposer cet appareil pour pleuvoir ou l'humidité.
Ne pas utiliser l’appareil près de l’eau.
Le nettoyer à l’aide d’un tissus sec.
Ne pas bloquer les ouvertures de ventilation, installer
selon les consignes du fabricant.
Eloigner des sources de chaleur tel: radiateurs,
fourneaux ou autres appareils qui produisent de la
chaleur.
Ne pas modifier ou amputer le système de la mise à
terre. Une prise avec mise à terre comprend deux lames
dont une plus large ainsi qu’une mise à terre: ne pas la
couper ou la modifier. Si la prise murale n’accepte pas
la fiche, consulter un électricien pour qu’il remplace la
prise désuète.
Protéger le cordon de secteur contre tous bris ou
pincement qui pourraient l’endommager, soit à la fiche
murale ou à l’appareil.
N’employer que les accessoires recommandés par le
fabricant.
N’utiliser qu’avec les systèmes de fixation,chariots,
trépied ou autres, approuvés par le fabricant ou vendus
avec l’appareil.
Débrancher l’appareil lors des orages électriques ou si
inutilisé pendant une longue période de temps.
Un entretient effectué par un centre de service accrédité
est exigé si l’appareil a été endommagé de quelque
façon: si il a été exposé à la pluie,, l’humidité ou s’il ne
fonctionne pas normalement ou qu’il a été échappé.
All Rights Reserved
Troubleshooting - 9
Dimensions - 9
Specifications - 10
Warranty - 11
This manual uses a
Perpetual Table Of
Contents. Each page
has a copy of the
manual’s contents in a
gray box just like this
one. The section you are
in will always be bold
with the other sections
“grayed out.” The feature
allows you to jump
directly to another
section without having to
return to a Table Of
Contents page.
Page - 4
Operator Manual – LX-308B Mixer
Safety Instructions – 3
Introduction - 4
LX-308B Mixer – 5
Connectors & Cables – 5
Physical Description - 6
Installation – 7
Typical Applications - 8
Troubleshooting - 9
Dimensions - 9
Specifications - 10
Warranty - 11
Introduction
Congratulations on your purchase of an Ashly LX-308B stereo line-level mixer. In one
compact rack-mount package we have combined features, reliability, and sonic performance
you have come to expect from Ashly. Features of this unit include:
Eight balanced stereo inputs for line level sources
On/Off switches to all eight inputs
Peak signal detection on all inputs
The first two inputs have a switchable 30dB gain for low impedance mics
Concentric level and pan controls for each input
Submaster inputs and outputs
Ultra low-noise summing amplifiers
6-segment LED meter arrays
Separate level controls for stereo, mono, and headphone outputs.
About Ashly
Ashly Audio was founded in 1974 by a group of recording engineers, sound professionals,
and electronics designers. The first products were custom consoles for friends and
associates, but business quickly grew. The philosophy established from the very beginning
holds true today: to offer only the highest quality audio tools at an affordable cost to the
professional user – ensuring reliability and long life. More than thirty years later, Ashly
remains committed to these principles.
Copyright© 2007 – Ashly Audio Inc.
Operator Manual – LX-308B Mixer
Page - 5
Safety Instructions – 3
LX-308B Mixer
Introduction - 4
The LX-308B is a versatile rack-mountable mixer capable of supporting the following
applications:
Small Sound Reinforcement
Church or School Mixing
MIDI Recording System
Sub-mixing in a larger system
These applications are discussed in detail on Page 8.
LX-308B Mixer – 5
Connectors & Cables – 5
Grounding
Physical Description - 6
Installation – 7
Typical Applications - 8
Troubleshooting - 9
Dimensions - 9
Connectors & Cables
Specifications - 10
The LX-308B Mixer uses 1/4” TRS connectors for all inputs and outputs. Stereo inputs use
two 1/4" TRS jacks per channel, with (+) signal on the tip, the (-) signal on the ring, and
ground on the sleeve. If you wish to drive a mono source into the stereo mix, simply plug
your signal into the right channel input.
LX-308B Connector Polarities
If low level and high level lines, or if either of these lines and speaker cables are run parallel
for long distances, crosstalk may be significant. In fact, the crosstalk can cause an electronic
feedback loop, oscillation, and possibly damage to the equipment. To minimize crosstalk,
physically separate low-level cables from speaker cables. 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.
Unbalanced Connections and Grounding
If you must use unbalanced connectors, the negative lead of the connector should be tied to
the ground lead. Using unbalanced connections could result in chassis ground-loop noise.
Altering the signal/chassis ground relationship in equipment connected to your unit may
eliminate the noise.
All Rights Reserved
Warranty - 11
Page - 6
Operator Manual – LX-308B Mixer
Safety Instructions – 3
Introduction - 4
LX-308B Mixer – 5
Connectors & Cables – 5
Physical Description
The LX-308B is 1RU, and weighs 10 pounds.
LX-308B Front Panel
Physical Description - 6
Front Panel
Rear Panel
Installation – 7
Typical Applications - 8
Troubleshooting - 9
1.
Dimensions - 9
Specifications - 10
2.
Warranty - 11
3.
4.
5.
Channel Level - This is the individual channel
volume control, which feeds a channel to the
main mix.
Channel Pan - This control adjusts the position
of the channel in the stereo mix.
Mic/Line Switch - This switch on the first two
inputs increases the channel input sensitivity by
30 dB to allow the use of low impedance
dynamic microphones.
On/Off (mute) Switch - This switch on each
channel will turn the channel completely off
allowing the channel level to remain at its
desired setting when the input is not needed.
Output Meters - A pair of peak detecting 6segment 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. This meter pair monitors the main
stereo output (0 VU = +4dBu). The red clipping
LED's also monitor the summing amplifiers,
making it possible for these indicators to
illuminate even with the stereo output level
turned off.
6.
Stereo Output Level - This is the main master
gain, which sets the operating level for the
entire mixer. This control does not effect the
mono output level.
7. Stereo Output Mute - This switch entirely
mutes the main stereo output. The headphone
and mono output are not affected. This is
particularly useful when the LX-308 is used as
a sub-mixer.
8. Mono Level - This is the master gain control
for the mono output, which is the combined
signal of the left and right outputs. It has no
effect on the stereo output.
9. Stereo Headphones Level - This adjusts the
volume level of the front panel headphone jack
10. Power Indicator LED – When illuminated,
indicates that the rear power switch is in the
ON position.
Copyright© 2007 – Ashly Audio Inc.
Operator Manual – LX-308B Mixer
Page - 7
LX-308B Rear Panel
Safety Instructions – 3
Introduction - 4
LX-308B Mixer – 5
Connectors & Cables – 5
1.
2.
Power Switch - This switches the AC power to
the LX-308B. When switched ON the frontpanel LED will illuminate.
Inputs - The LX-308B stereo inputs use two
20K balanced 1/4" TRS jacks per channel,
with (+) signal on the tip, the (-) signal on the
ring, and ground on the sleeve. If you wish to
drive a mono source into the stereo mix, simply
plug your signal into the right channel input.
Channels 1 and 2 are switchable to add 30dB
gain for low impedance dynamic microphones.
3.
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Sub Inputs - The Sub inputs are nominal
10K unbalanced types on 1/4" TRS jacks.
They feed directly to the mix busses at a
nominal +4dBu level and are useful for coupling
multiple mixers.
Sub Outputs - The Sub Outputs are
unbalanced types on 1/4" TRS jacks. Typically,
they will feed sub inputs on additional mixers.
Nominal operating level is +4 dBu.
Main Outputs - Outputs are 200 1/4" TRS
jacks and can be wired balanced or
unbalanced. Nominal operating level is +4 dBu
and maximum headroom is +22dBu.
Installation
Always switch the unit off before making substantial changes to the settings or connectors. Use
four screws and washers when rack mounting. This unit has specific electrical and signal
requirements, please take special care to double check all connections and settings and refer to
the specifications section of this manual. The unit should be connected to a standard 3-wire
grounded electrical outlet supplying 100-240 Volts, 50-60 Hz. To reduce the risk of ground
loop hum, connect all audio equipment to the same electrical power source. Removal of the
ground pin is both unlawful and dangerous, as a potential shock hazard could result. Overall
power consumption is less than 12 watts.
NOTE: The power switch does NOT isolate the appliance from mains. Make sure the mains
power socket or an alternative disconnect device is near by and easily accessible. When the
product is connected to mains, the line-filter and the input of the fuse are energized.
All Rights Reserved
Physical Description - 6
Front Panel
Rear Panel
Installation – 7
Typical Applications - 8
Troubleshooting - 9
Dimensions - 9
Specifications - 10
Warranty - 11
Page - 8
Operator Manual – LX-308B Mixer
Safety Instructions – 3
Introduction - 4
Typical Applications
LX-308B Mixer – 5
The following information will help you make the most of your new mixer:
Connectors & Cables – 5
Small Sound Reinforcement System
Physical Description - 6
Installation – 7
Typical Applications - 8
Small Reinforcement
Church/School
MIDI Recording
Submixing
Troubleshooting - 9
Dimensions - 9
Specifications - 10
Warranty - 11
The LX-308B can be used to mix typical sound sources that might be found in a small
club, school theater or similar environment. INPUT channels 1 & 2 are used for
microphones for live vocal or instrumental pickup. INPUT channels 3-8 are used for the
output of electronic music devices such as keyboards, MIDI sound modules, drum
machines, etc. The SUB OUT jacks provide feeds to a cassette deck (or any recording
device) for making a recording of the mix. The power amplifier (or any additional graphic
equalizers or electronic crossovers which may be used) is fed from the MAIN OUTPUT
connectors.
Church School or Meeting Room Mixing
The LX-308B can be used to mix sources typically found in a church, classroom, or
meeting room. The first two INPUTS are used for microphones for live vocal or
instrumental pickup. The third INPUT can be a feed from an electronic keyboard. The
remaining INPUT channels are used for audio devices such as film projector or video
player, a cassette deck, a CD player, and perhaps even a turntable (with user-supplied
RIAA preamp). One input channel is reserved as a spare. The SUB OUT jacks feed a
cassette deck (or any recording device) for making a recording of the mix. The power
amplifier (or any additional equalizer or electronic crossover which may be used) is fed
from the MAIN OUTPUT connectors.
MIDI Recording
The LX-308B can be used to record directly from a MIDI studio setup. INPUTS one and
two are from MIDI keyboards. INPUTS 3-6 are from MIDI sound modules, and INPUTS 7
& 8 are from a multitrack tape recorder, synced externally to the MIDI controller. The
MAIN OUTPUTS provide a stereo feed directly to a two-track mixdown tape recorder.
Submixer In Larger Sound System:
The LX-308B can be used to provide a mix from the MIDI keyboard setup to the main
mixer without tying up a number of channels on the main console. Up to eight INPUTS
(more if several LX-308B units are linked) can be "pre-mixed" in stereo. Either the main
OUTPUT or the SUB OUT connectors can be used to feed the mixed keyboard signal to
the main mixer.
Copyright© 2007 – Ashly Audio Inc.
Operator Manual – LX-308B Mixer
Page - 9
Safety Instructions – 3
Troubleshooting
Introduction - 4
Situation
Action
LX-308B Mixer – 5
No Sound
Check the AC power. Is the power switch 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.
Something is being overdriven in the signal path. If the clip indicators are active, reduce the
channel level controls. If the clip indicators are still active, reduce the input signal level. 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.
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.
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.
Connectors & Cables – 5
Distorted Sound
Excessive Noise
Excessive Hum or Noise
Note: Unshielded cables, improperly wired connections, and cable with broken strands are
the most common problems. Make sure you use good quality cable with connectors
soldered firmly on the correct pin. When in doubt, get in touch with your Ashly dealer.
Dimensions
In Inches
All Rights Reserved
Physical Description - 6
Installation – 7
Typical Applications - 8
Troubleshooting - 9
Dimensions - 9
Specifications - 10
Warranty - 11
Page - 10
Safety Instructions – 3
Introduction - 4
Operator Manual – LX-308B Mixer
Specifications
LX-308B
LX-308B Mixer – 5
SPECIFICATION
DISTORTION
Connectors & Cables – 5
THD at +20 dBu, 20Hz-20KHz, input switch at -40dB
<0.02%
IMD (SMPTE) at +20dBu
<0.01%
Physical Description - 6
Installation – 7
Typical Applications - 8
Troubleshooting - 9
Dimensions - 9
Specifications - 10
Warranty - 11
HUM & NOISE (20Hz-20Khz)
<-98dBu
<-90dBu
Residual output noise, all levels at minimum
MASTER OUT, MASTER LEVEL and one INPUT LEVEL at unity gain
VOLTAGE GAIN (dB ± 1)
0dB
INPUTS or SUB INPUTS to MASTER OUTPUTS (levels at nominal)
INPUT to MASTER OUTPUT (levels at max)
25dB
Ch.1 or Ch.2 INPUT in MIC position to MASTER OUTPUTS
SUB INPUTS to MASTER OUTPUTS (master level at max)
56dB
18dB
±0.2dB
Frequency Response - 20Hz-20Khz
0VU = +4dBu
VU METERS - Two 6-segment LED meters
Peak Clip indicator on each input channel and left and right
outputs, illuminates 3dB below clipping
13 lbs. Maximum
PEAK INDICATORS
SHIPPING WEIGHT
100-240 Volts, 50-60 Hz, 30 watts
POWER REQUIREMENTS
Input Specifications
Input
Balanced/
Unbalanced
Load Impedance
For use w/
Nominal
Max Input before
Clip
Connector
Line Inputs 1-2
Line Inputs 3-8
Balanced
Balanced
20K 20K 600
600
+21 dBu
+21 dBu
L & R 1/4” TRS
L & R 1/4” TRS
Mic Inputs (1-2)
Balanced
20K 600
-10 dBu
L & R 1/4” TRS
Sub Inputs
10K L & R 1/4” TRS
Unbalanced
600
+22 dBu
Unless otherwise stated, specification conditions are: 150 source, all levels set at nominal, outputs into 2.7K or greater
Output Specifications
Output
Balanced/
Unbalanced
For use w/
Nominal
Output Level
Nominal
Output Level Max
before Clip
Connector
Balanced
Source
Impedance
200 Master Out (L, R)
10 K lines
+4 dBu
+22 dBu
1/4” TRS
Mono Out
Balanced
200 10 K lines
+4 dBu
+22 dBu
1/4” TRS
Sub Out (L, R)
Unbalanced
200 10 K lines
-4 dBu
+22 dBu
1/4” TRS
Notes: 1. 0 dBu = 0.775 Vrms 2. Sensitivity is input signal level which will produce +4 dBu out with all levels maximum
Copyright© 2007 – Ashly Audio Inc.
Operator Manual – LX-308B Mixer
Page - 11
Introduction
Safety
Instructions
-2
–3
Limited Warranty
The PE Series
Introduction
- 4- 3
Warranty service for this unit will be provided by ASHLY AUDIO INC. in accordance with
the following warrant statement.
ASHLY AUDIO INC. warrants to the owner of this product that this product and the
components thereof, will be free from defects in workmanship and materials for a period of
FIVE years from the date of purchase. ASHLY AUDIO INC. (ASHLY AUDIO) will,
without charge, repair or replace, at its option, defective product or component parts upon
prepaid delivery to the factory service department or authorized service center, accompanied
by proof of purchase date 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. This warranty is void if the serial number is altered,
defaced, or removed. ASHLY AUDIO 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 date of purchase of the product. Ashly Audio shall be liable only
to correct defects in the product itself, and not for any damage or injury which may result from
or be incidental to or a consequence of such defect. Some states do not allow either 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 in the United States
For warranty service in the United States, please follow this procedure:
Return the product to Ashly, freight prepaid, with a written statement describing the defect
and application the product is used in. Ashly Audio will examine the product and perform
any necessary service, including replacement of defective parts, at no further cost to you.
Ship your product to:
Ashly Audio Inc.
Attn: Service Department
847 Holt Road
Webster, NY 14580-9103
For units purchased outside The United States of America, service will be provided by an
authorized distributor of ASHLY AUDIO INC.
Obtaining Warranty Service Outside the United States For units purchased outside The
United States of America, service will be provided by an authorized distributor of ASHLY
AUDIO INC.
All Rights Reserved
Physical Description
LX-308B
Mixer – 5 - 4
Installation –&5Cables – 5
Connectors
OperationDescription
Physical
–7
-6
Troubleshooting
Installation
–7 -8
Spec Table
Typical
Applications
-9
-8
Measurements - -109
Troubleshooting
Dimensions - 11
9
Warranty - 12 - 10
Specifications
Warranty - 11
Copyright© 2007 – Ashly Audio Inc.