LX-308B
Stereo
Line/Microphone
Mixer
Operating Manual
Ch.1
Line
4
Mic
(+30dB)
5
Ch.2
6
Line
4
Mic
(+30dB)
7
5
Ch.3
7
8
8
1
L
R
Mute
On Level
Pan
9
4
6
1
L
Mute
On Level
R
Pan
9
5
Ch.4
6
3
4
7
2
1
8
L
Mute
On Level
R
9
Pan
5
Ch.5
6
3
4
7
2
1
8
L
Mute
On Level
R
9
Pan
5
Ch.6
6
3
4
7
2
1
8
L
Mute
On Level
R
9
Pan
5
Ch.7
6
3
7
2
1
4
8
L
Mute
On Level
R
9
5
3
4
7
2
1
8
L
Mute
On Level
-L-
Ch.8
6
R
9
Pan
5
3
7
2
1
8
L
Mute
On Level
R
Clip
Stereo
Output
-R-
+6
6
9
Pan
0
-6
-12
-20
Output
VU
4
5
Mono/Phones
Output
4
6
3
8
1
L
Level
R
Pan
5
6
3
7
2
1
9
Stereo
Output
Mute
7
2
0
Mono
10
LX308B
Stereo
Eight Channel
Line Level Mixer
9
On
Phones
ASHLY AUDIO INC.
847 Holt Road Webster, NY 14580-9103 Phone: (716) 872-0010
Toll-Free: (800) 828-6308 Fax: (716) 872-0739
www.ashly.com
Power
Operating Manual - LX-308B Stereo Line/Microphone Mixer
Table Of Contents
1
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2
UNPACKING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3
AC POWER REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4
SECURITY COVERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
5
CONTROLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
6
CONNECTIONS AND CABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
7
TYPICAL APPLICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7.1 Small Sound Reinforcement System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7.2 Church, School Or Meeting Room Sound System . . . . . . . . . . . . . . . . . . . . . . . . .
7.3 MIDI Recording System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7.4 Submixer In Larger Sound System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8
TROUBLESHOOTING TIPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
9
DIMENSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6
6
6
7
7
10 SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
11 WARRANTY INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
12 SCHEMATIC DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2
Operating Manual - LX-308B Stereo Line/Microphone Mixer
ing 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.
1. INTRODUCTION
Congratulations on your purchase of an Ashly
LX-308B stereo line level mixer. The LX308B improves
upon the LX308 with the addition of On/Off switches to all
eight inputs, and peak signal detection on all inputs. Other
features include eight balanced stereo inputs for line level
sources, the first two inputs with switchable 30dB gain for
low impedance dynamic microphones. A concentric level
and pan control for each input adjusts channel volume and
stereo position. Submaster inputs and outputs are provided
for cascading two or more mixers. Ultra low-noise summing amplifiers combine the channel signals for the main
outputs. A pair of 6-segment LED meter arrays monitor the
main output levels. Separate level controls are provided for
stereo, mono, and headphone outputs.
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 LX-308B mixer will perform normally from
95 to 125 volts AC. Use only properly grounded AC receptacles. To reduce the risk of ground loop hum, use a
central point for system AC power distribution. The AC
line fuse is internal, and should only be changed by a
qualified service technician.
2. UNPACKING
4. SECURITY COVERS
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 pack-
For installations where it is desirable to protect
the front panel controls from tampering or accidental
misadjustment, use the Ashly security cover, which is
available in both single and double rack space sizes. Installation is simple and does not require removal of the
equipment from your rack. See your Ashly dealer for
details.
Ashly Security Cover Installation
3
Operating Manual - LX-308B Stereo Line/Microphone Mixer
Ch.1
Line
Mic
4
5
6
(+ 3 0 dB)
Ch.2
Line
Mic
4
(+ 3 0 dB)
7
5
Ch.3
6
7
L
Mute
On Level
R
Pan
AC
1
9
L
Mute
On Level
50-60Hz
12W
4
7
2
9
8
1
L
Mute
On Level
Pan
6
R
Pan
5
Ch.
6
3
4
7
2
9
Made In USA
LX308B
Mic/Line
Mixer
3
8
1
Mute
On
L
Level
R
9
2
1
L
Mute
On Leve
Pan
-L-
Outputs
Ch.8
-R120VAC .1A
5. CONTROLS
5.1 Channel Level
This is the individual channel volume control
which feeds a channel to the main mix.
5.2 Channel Pan
This control adjusts the position of the channel
in the stereo mix.
5.3 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.
5.4 On/Off 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.
5.5 Output Meters
A pair of peak detecting 6-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. This meter pair monitors the main stereo output (0 VU = +4dBu). The red clipping LED's also moni-
4
R
Ch.4
3
8
8
1
4
5
Mono
-L-
-R-
Sub Out
Sub In
tor the summing amplifiers, making it possible for these
indicators to illuminate even with the stereo output level
turned off.
5.6 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.
5.7 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.
5.8 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.
5.9 Stereo Headphones Level
This adjusts the volume level of the front panel
headphone jack.
5.10 Power Switch
This switches the AC power to the LX-308B.
When it is pressed in the adjacent LED will become lit.
-L-
-R-
(M o n
Operating Manual - LX-308B Stereo Line/Microphone Mixer
-L-
Ch.8
5
4
+6
6
3
R
Mute
On Level
9
Pan
Output
VU
-L-
L
R
Level
-R-
(M o no )
-L-
1
Stereo
Output
Mute
0
10
-R-
-L-
Stereo
Eight Channel
Line Level Mixer
9
On
Mono
Ch.3
(M o no )
LX308B
7
2
9
Pan
Ch.4
6
3
7
8
1
-20
5
4
6
2
-12
Ch.5
5
Mono/Phones
Output
3
-6
8
L
4
0
7
2
1
Stereo
Output
-RClip
Phones
Ch.2
-R-
(M o no )
-L-
6. CONNECTIONS AND CABLES
6.1 Inputs
The LX-308B stereo inputs use two 20KΩ
balanced 1/4" phone 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.
6.2 Sub Inputs
The Sub inputs are nominal 10KΩ unbalanced
types on 1/4" phone jacks. They feed directly to the mix
busses at a nominal +4dBu level and are useful for coupling multiple mixers
6.3 Sub Outputs
The Sub Outputs are unbalanced types on 1/4"
phone jacks. Typically, they will feed sub inputs on additional mixers. Nominal operating level is +4 dBu.
Power
Ch.1
-R-
(Mic/Mo no )
-L-
-R-
(Mic/Mo no )
6.4 Main Outputs
Outputs are 200Ω "pseudo-balanced" 1/4" phone
jacks, which means they have balanced impedance with a
single-ended signal source and can be wired balanced or
unbalanced. Nominal operating level is +4 dBu and maximum headroom is +22dBu.
6.5 Wiring Suggestions:
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.
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Operating Manual - LX-308B Stereo Line/Microphone Mixer
7. TYPICAL APPLICATIONS
7.1 Small Sound
Reinforcement System:
In the setup shown
here, the LX-308B is 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.
(Note: Connections shown are AUDIO connections only. MIDI connections are not illustrated.)
7.2 Church, School Or Meeting Room Sound System:
Here the LX-308B is 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 receives 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.
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Operating Manual - LX-308B Stereo Line/Microphone Mixer
7.3 Midi Recording System:
In this setup the
LX-308B is used to create a recording 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 twotrack mixdown tape recorder.
(NOTE: Connections shown are
AUDIO connections only.
MIDI connections are not illustrated)
7.4 Submixer In Larger
Sound System:
In this application the
LX-308B is 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.
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Operating Manual - LX-308B Stereo Line/Microphone Mixer
8. TROUBLESHOOTING TIPS
8.1 No Sound
Check the AC power. Is the power switch on and
illuminated? Check the level meters. If they are operating, the problem between the mixer and the later components in the system. If not, check to see you really have
an input signal and that it is on the desired channel. Check
that you have the master gain controls at the desired operating level.
8.2 Distorted Sound
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.
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. Turn up the
channel level 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.
If you need help, get in touch with your Ashly
dealer or call an Ashly technical service representative at
1-800-828-6308.
9. DIMENSIONS
17.00
6.00
0.10
1.25
1.75
1.15
Figure 9.1: Dimensional Drawing for LX-308B Mic/Line Mixer
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Operating Manual - LX-308B Stereo Line/Microphone Mixer
10. SPECIFICATIONS
DISTORTION
THD at +20 dBu, 20Hz-20KHz . . . . . . . . . . . . . <0.02%
IMD (SMPTE) at +20dBu . . . . . . . . . . . . . . . . . . <0.01%
HUM & NOISE (20Hz-20KHz)
residual output noise, all levels at minimum <-100dBu
MASTER OUT, MASTER LEVEL and one
INPUT LEVEL at nominal (unity gain) . . . . . <-87dBu
FREQUENCY RESPONSE
20Hz-20KHz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±0.2dB
VOLTAGE GAIN (dB±1)
INPUTS or SUB INPUTS to
MASTER OUTPUTS (levels at nominal) . . . . . . . . 0dB
INPUT to MASTER OUTPUT (levels at max) . . . 25dB
Ch.1 or Ch.2 INPUT in MIC position to
MASTER OUTPUTS . . . . . . . . . . . . . . . . . . . . . . . . 56dB
SUB INPUTS to MASTER OUTPUTS
(master level at max) . . . . . . . . . . . . . . . . . . . . . . . . 18dB
CROSSTALK
adjacent inputs or input to output at 1KHz . . . . <-80dB
adjacent inputs or input to output at 20KHz . . <-60dB
VU METERS
Two 5-segment LED meters. . . . . . . . . . . . . 0VU=+4dBu
PEAK INDICATORS
activated when internal signal is 3dB below clipping
SHIPPING WEIGHT
9 lbs. maximum
POWER REQUIREMENTS
120 VAC nominal, 93 VAC minimum, 50-60 Hz,
12 watts (240 VAC available)
*unless otherwise stated, specification conditions are:
150Ω source, all levels set at nominal, outputs into 2.7KΩ
or greater.
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Operating Manual - LX-308B Stereo Line/Microphone Mixer
11. WARRANTY INFORMATION
Thank you for your expression of confidence in Ashly products. The unit you have just purchased is protected
by a five-year warranty. To establish the warranty, be sure to fill out and mail the warranty card attached to your
product. Fill out the information below for your records.
Model Number _______________________________________________________________________________
Serial Number ________________________________________________________________________________
Dealer ______________________________________________________________________________________
Date of Purchase _____________________________________________________________________________
Dealer’s Address ______________________________________________________________________________
____________________________________________________________________________________________
Dealer’s Phone _______________________________________________________________________________
Salesperson __________________________________________________________________________________
10
12. SCHEMATIC DIAGRAMS
Operating Manual - LX-308B Stereo Line/Microphone Mixer
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Operating Manual - LX-308B Stereo Line/Microphone Mixer
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Operating Manual - LX-308B Stereo Line/Microphone Mixer
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Operating Manual - LX-308B Stereo Line/Microphone Mixer
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Operating Manual - LX-308B Stereo Line/Microphone Mixer
NOTES:
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Operating Manual - LX-308B Stereo Line/Microphone Mixer
ASHLY AUDIO INC. 847 Holt Road Webster, NY 14580-9103
Phone: (716) 872-0010 Fax: (716) 872-0739
Toll Free (800) 828-6308
www.ashly.com
 1996-2000 by Ashly Audio Corporation. All rights reserved worldwide.
Printed in USA 10/00
LX Rev 1