RedSeven Amplification DOUBLE STEREO LINE MIXER User manual

DOUBLE stereo LINE MIXER
model: DSLM
User Manual
INPUT OUT LEFT OUT RIGHT
SENDFX1 RTN 9VDC
DOUBLE
STEREO
LINE MIXER
TRANSFORMER ISOLATED
T = mono R = stereo
T = mono R = stereo
FX2 RTN
T = mono R = stereo
(MONO) (STEREO)(MONO)

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2!
INDIEX
INTRODUCTION pg 3
POWER SUPPLY pg3
!! WARNING !! pg 3
TECHNICAL FEATURES pg 4
CONNECTION EXAMPLES pg 6
TROUBLESHOTTING pg 11
WARRANTY pg 11

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3!
INTRODUCTION
Double Stereo Line Mixer is a line level professional device for parallel processing, with a fixed mix of
50/50 (dry/wet).
Thought as the ultimate and most compact solution in the business to mix up to two stereo returns
with incoming dry signal into a single stereo output.
To avoid any ground loop issue, sends and returns are transformer isolated.
The whole unit can operate at nominal +4db line level signal.
POWER SUPPLY
Double Stereo Line Mixer must operate ONLY at 9 volte negative center @100mA. Any other voltage
could seriously damage the unit. His internal charge pump guarantees the optimal headroom. Do not
try to apply 12 or more volts in the aim to increase the headroom, this will 100% break down the unit.
!! WARNING !!
This is a line mixer with an internal dedicated DRY PATH. This mean you MUST set the mix of your
external effects to 100% wet, or where you can, to turn on KILL DRY.
The goal with this mixer is to preserve your dry tone and let the mixer take care of it, so don’t let any
portion of dry signal passing thru your external effects.

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4!
TECHNICAL FEATURES
(right side)
• INPUT (mono):this is the main input of the mixer, mono.
• OUT LEFT (mono):left output of the system. If only the left output is used (right
output is not plugged in) the mixer will sum right and left into this output).
• OUT LEFT (stereo):right output of the system. If right output is plugged in, the
stereo signal will be preserved as left and right on respective outputs.
(left side)
• SEND: this output will split incoming signal from INPUT to other two equal copy.
If you use a mono connector, you will have one outgoing signal (on TIP), if you
use a stereo connector you will have two equal copies of INPUT signal (first one
on TIP, second one on RING). Suggestion: if you want to split SEND signal use a Y cable (stereo
– mono/mono cable).
• 9VDC: 9 volts negative center power supply connector. Use only high quality
power supply with at least clean 100mA supply.
• FX1 RETURN: this input will accommodate the mono or stereo return of your
first effect. If you’re using a mono effect, a mono cable will work, if you’re using a
stereo output from your effect you must use a Y cable to accommodate left and
right signal into FX1 RETURN jack.
• FX2 RETURN:this input will accommodate the mono or stereo return of your
second effect. If you’re using a mono effect, a mono cable will work, if you’re
INPUT OUT LEFT OUT RIGHT
SENDFX1 RTN 9VDC
DOUBLE
STEREO
LINE MIXER
TRANSFORMER ISOLATED
T = mono R = stereo
T = mono R = stereo
FX2 RTN
T = mono R = stereo
(MONO) (STEREO)(MONO)

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5!
using a stereo output from your effect you must use a Y cable to accommodate
left and right signal into FX2 RETURN jack

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6!
CONNECTION EXAMPLES
Example 1 - One mono effect with a mono guitar amplifier.
Signal comes from amp’s loop fx send (INPUT), one copy is sent to external effect input
(SEND) then the output of external effect is sent back to FX1 RETURN. OUT LEFT is
routed back into amp’s loop fx RETURN.
Suggestion: use mono (unbalanced) connectors and wire for this particular application.
INPUT OUT LEFT OUT RIGHT
SENDFX1 RTN 9VDC
DOUBLE
STEREO
LINE MIXER
TRANSFORMER ISOLATED
T = mono R = stereo
T = mono R = stereo
FX2 RTN
T = mono R = stereo
(MONO) (STEREO)(MONO)
AMP
RETURN
AMP
SEND
FX1
output
FX1
input

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7!
Example 2 - Two mono effects with a mono guitar amplifier.
Signal comes from amp’s loop fx send (INPUT), first copy is sent to external effect input
1, second copy is sent to external effect input 2 with a Y CABLE (SEND).
The output of external effect 1 is sent to FX1 RETURN, output of external effect 2 is sent
to FX2 RETURN. OUT LEFT is routed back into amp’s loop fx RETURN by putting in
parallel FX1 and FX2 returns.
Suggestion: use Y cable with stereo connector only where indicated.
INPUT OUT LEFT OUT RIGHT
SENDFX1 RTN 9VDC
DOUBLE
STEREO
LINE MIXER
TRANSFORMER ISOLATED
T = mono R = stereo
T = mono R = stereo
FX2 RTN
T = mono R = stereo
(MONO) (STEREO)(MONO)
AMP
RETURN
AMP
SEND
FX1
output
FX2
input
FX1
input
FX2
output
(FX 1 + FX2)

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8!
Example 3 - Two mono effects with two guitar amplifiers (or stereo power amplifier).
Signal comes from amp’s loop fx send (INPUT), first copy is sent to external effect input
1, second copy is sent to external effect input 2 with a Y CABLE (SEND).
The output of external effect 1 is sent to FX1 RETURN, output of external effect 2 is sent
to FX2 RETURN. OUT LEFT is routed back into left power section of the amplifier, OUT
RIGHT is routed back into right power section of the amplifier.
Suggestion: use Y cable with stereo connector only where indicated.
Suggestion: if you desire mixing two effects but you want to go back to a mono out, you can always use only OUT
LEFT. In this way FX1 & FX2 retursn will automatically mixed in mono on OUT LEFT.
INPUT OUT LEFT OUT RIGHT
SENDFX1 RTN 9VDC
DOUBLE
STEREO
LINE MIXER
TRANSFORMER ISOLATED
T = mono R = stereo
T = mono R = stereo
FX2 RTN
T = mono R = stereo
(MONO) (STEREO)(MONO)
AMP
RETURN L
AMP
SEND
FX1
output
FX2
input
AMP
RETURN R
FX2
output
FX1
input

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9!
Example 4 - One stereo effect with two guitar amplifiers (or stereo power amplifier).
Signal comes from amp’s loop fx send (INPUT), first copy is sent to left side of effect
input , second copy is sent to right side of effect input with a Y CABLE (SEND).
Left output of external effect is sent to FX1 RETURN (tip), right output of external effect
is sent to FX1 RETURN (ring) with a Y CABLE.
OUT LEFT is routed back into left power section of the amplifier, OUT RIGHT is routed
back into right power section of the amplifier.
Suggestion: use Y cable with stereo connectors only where indicated.
Suggestion: if you desire mixing two effects but you want to go back to a mono out, you can always use only OUT
LEFT. In this way FX1 & FX2 retursn will automatically mixed in mono on OUT LEFT.
INPUT OUT LEFT OUT RIGHT
SENDFX1 RTN 9VDC
DOUBLE
STEREO
LINE MIXER
TRANSFORMER ISOLATED
T = mono R = stereo
T = mono R = stereo
FX2 RTN
T = mono R = stereo
(MONO) (STEREO)(MONO)
AMP
RETURN L
AMP
SEND
FX1
output L
FX1
input R
AMP
RETURN R
FX1
output R
FX1
input L

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10!
Example 5 - Two stereo effects with two guitar amplifiers (or stereo power amplifier).
Signal comes from amp’s loop fx send (INPUT), first copy is sent to external effect input
1, second copy is sent to external effect input 2 with a Y CABLE (SEND).
Left output of external effect 1 is sent to FX1 RETURN (tip), right output of external
effect 1 is sent to FX1 RETURN (ring) with an Y CABLE.
Left output of external effect 2 is sent to FX2 RETURN (tip), right output of external
effect 2 is sent to FX2 RETURN (ring) with an Y CABLE.
OUT LEFT is routed back into left power section of the amplifier, OUT RIGHT is routed
back into right power section of the amplifier.
Suggestion: use Y cable with stereo connectors only where indicated.
Suggestion: if you desire mixing two effects but you want to go back to a mono out, you can always use only OUT
LEFT. In this way FX1 & FX2 retursn will automatically mixed in mono on OUT LEFT.
INPUT OUT LEFT OUT RIGHT
SENDFX1 RTN 9VDC
DOUBLE
STEREO
LINE MIXER
TRANSFORMER ISOLATED
T = mono R = stereo
T = mono R = stereo
FX2 RTN
T = mono R = stereo
(MONO) (STEREO)(MONO)
AMP
RETURN L
AMP
SEND
FX1
output L
FX1
input R
AMP
RETURN R
FX1
output R
FX2
output L
FX2
output R
FX1
input L

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11!
TROUBLESHOTTING
• Dual Stereo Line Mixer is not turning on (led indicator is not turning on) .
Please, check you power supply and be sure it will output 9V with negative center
connector with a multimeter. If the problem persist, contact RedSeven
Amplificaton.
• Dual Stereo Line Mixer is turning on but with no sound.
First of all check and double check all of your cables, and we mean, ALL OF THEM.
99% of the time the problem is a faulty cable. Then check your external effects
by trying them in series as any traditional overdrive.
If the problem persist, contact RedSeven Amplificaton.
• I’m hearing a strange chorused/flangy sound coming form the OUT
LEFT/RIGHT
Be sure to set your external effects in KILLDRY mode or if there’s no possibility to
do this, be sure to put the mix on your external effects on 100%.
The goal is to NOT have any dry signal passing thru external effects.
For any problem and in any moment you can contact a qualified tech at:
[e-mail]
We will replay to you as soon as possibile.
WARRANTY DESCLAMER
Please, do not try to open the amplifier in any case. For any problem contact your seller
or write to us. This amplifier runs at very high voltage that can lead to death. Any
inexpert person should not even think of do anything inside this amplifier. RedSeven
Amplification offer a standard two year fully warranty for any component (except to
wear subjects).
By removing the amplifier form his wood cabinet or by making any modification to the
original state will violate standard warranty and RedSeven Amplification will not
responsible for any damage to people, things or animals.

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Revision 1.0
September 2019