N-audio 8X7 User manual

Models 8X7 and 4X4
User Manual
Amplifier Cabinet Switching Systems

THANK YOU for choosing the N-audio Amp Cabinet
Switcher, and welcome to the N-audio family!
This manual will help you make the most of your Switcher
Front panel
1. INPUT - plug your guitar here. It disables the back input when in use.
2. MUTE/MIDI learn button for quickly muting the Switcher or adding a
preset via MIDI.
3. Amplifier buttons for switching between the connected amplifiers.
4. Power attenuator button for activating an external power attenuator.
5. Cabinet buttons for selecting the desired speaker cabinets.
6. Power button for turning the device on/off.
Introduction
These Switchers have been designed to make it easy for you to switch
between amplifiers and speaker cabinets, without having to manually
route cables. With the ability to handle up to 8 (4) amplifiers and up to 7 (4)
cabinets, along with an external power attenuator, they are great choice
for anyone looking to compare different guitar tones, change the sound
while recording, playing on stage or testing a lot of equipment quickly.
One of the great features of these Amp Cabinet Switchers is that they
work seamlessly with any type of amplifier, including tube, solid-state and
bridged mono amplifiers. They also include built-in hardware and
software protection to keep your amplifiers safe. The signal path consists
of relays only, ensuring a pure tone with no active electronics. A special
circuit has been implemented to reduce pops when switching, and there
are no dead spots when switching between amplifiers or cabinets,
making them perfect for use on stage or in the studio.
Controls and connectors

1. Mains IEC power supply connector.
2. Outputs to cabinets for sending signals to the speaker cabinets.
3. Send/return jack plugs for using an external power attenuator.
4. Jack plugs for connecting the speaker outputs from your amplifiers,
where you would normally plug in your cabinet.
5. MIDI IN and OUT connectors for external MIDI control.
6. Jack plugs for connecting to the inputs of your amplifiers, where you
would normally plug in your guitar.
7. Slave guitar input. It turns off when the front panel jack is used.
8. Tuner out jack plug for connecting an external tuner.
Connecting the whole rig
It's important to ensure that you have the right cables for your setup.
There are two types of cables commonly used: Guitar cables and
speaker cables. The use of quality shielded guitar cables and proper
2 2
speaker cables, where 2x1.5mm or 2x2.5mm is highly recommended.
Connecting the amplifiers
To connect the amplifiers, you will need two cables for each amplifier.
Follow these steps:
• Connect a shielded guitar cable from the input on the amplifier where
you would typically plug your guitar into the "to amplifiers inputs" jack.
• Connect a speaker cable from the cabinet jack on the back of your
amplifier, where you would normally connect an external speaker
cabinet, to the "from amplifiers speaker output" jack.
The jacks on the back of the Switcher correspond to the amplifier button
numbers on the front. It is crucial to connect each amplifier between
the same numbers on the back. Therefore, the cables from the first
amplifier should be connected to the first "to amplifiers inputs" and the
first "from amplifiers speaker outputs". Repeat this procedure for all other
amplifiers when connecting them to the Switcher.
!NEVER CONNECT ONE AMPLIFIER TO DIFFERENT JACK
NUMBERS ON THE BACK OF THE SWITCHER!
Back panel
!

AMP 1
To the guitar input
From the speaker
output on back
From
output To input
Cabinets
To tuner
AMP 2 To the
guitar input
From the speaker
output on back
GUITAR CABLES
SPEAKER CABLES
321
MIDI controller
MIDI cable
Guitar
Combo
GUITAR IN
/SLAVE/
Typical wiring
Please pay close attention when connecting the amplifiers. For optimal
performance and reducing the interferences among the cables, try to
keep some distance between the input guitar cables and output speaker
cables, if possible.
Connecting a guitar combo
Connect a shielded guitar cable from the input on the combo where you
would typically plug your guitar into the "to amplifiers inputs" jack of any of
the amplifier's inputs. Note that the second "from amplifiers speaker
output" jack plug is not used when playing with a combo. To enable
playing through a guitar combo, you will need to bypass the implemented
speaker cabinet protection of the Switcher. This can be done by enabling
one of the connected cabinets or the power attenuator by pressing and
holding the Power Att. button.
Connecting an external power attenuator
To use an external power attenuator with the N-audio 8X7 or 4X4
Switcher, simply follow these steps:
• Connect the input of the attenuator to the "to input/send" jack of the
amplifier using only speaker cable.
• Connect the output of the attenuator to the "from output/return" jack of
the amplifier using only speaker cable.
Connecting the cabinets
Connect the cabinets using speaker cables to the "to cabinets" jacks
Power On/Off sequences
Power-on sequence
1. Turn on the 4X4 Switcher.
2. Turn on the amplifiers.
3. Test each amplifier and cabinet with reduced volume.

Power-off sequence
1. Turn off the amplifiers
2. Turn off the 4X4 Switcher
When the Switcher is powered off, all amplifier inputs are
automatically muted and the outputs are connected to an internal
resistive load.
First use
When you first power on the device, it will perform an LED sequential
test while in a muted state. Each cabinet button on top of the device has a
dual-color LED: green indicates a connected cabinet, while if it is OFF, it
can't be selected.
Follow these steps to start playing:
1. Choose a cabinet by pressing its button. The active cabinet will be
indicated by a red LED.
2. Enable the attenuator, if needed.
3. Select an amplifier.
To avoid mistakes while routing the whole rig, start with reduced
master volume and increase it only when you hear a signal. During play,
you can select any possible cabinet, attenuator or amplifier using the
front panel buttons or via MIDI. If you press the Mute switch, you'll need to
start over by selecting a cabinet.
Extra features
Using more than one cabinet in parallel
To use more than one cabinet in parallel, simply press and hold the
button for the first cabinet, then press the button for the second cabinet.
Repeat this step to add a third cabinet. The unit can drive up to three
cabinets in parallel simultaneously. To exit this mode, press any of the
allowed cabinet buttons.
Press
and hold
Press to enable
second cabinet
Press
and hold
Press to enable
third cabinet

CAUTION! When adding cabinets in parallel, the output impedance
of the unit is reduced. For instance, two 8 Ohm cabinets in parallel have 4
Ohm output impedance. It is highly recommended to use 16 Ohm
cabinets when using this mode. Using more than one 4 Ohm cabinets
simulateniously can cause damage to the amplifier!
Silent recording via an external power attenuator
The Switcher normally only turns on an amplifier and the attenuator
when a cabinet is selected. However, it also offers an extra feature for
silent recording without driving a cabinet. To enable this mode, press and
hold the power attenuator button until its LED starts flashing. Once the
LED stays on, the attenuator is turned on and you can enable an amplifier
without a cabinet. To exit this mode, simply press the MUTE or POWER
ATT button.
CAUTION! Use this mode only when you have a power attenuator
connected to the Switcher!
Press and hold until stops flashing and stays on
Enable the desired amplifier
Hardware and software protections
The N-audio Switcher has built-in hardware and software protection to
safeguard the amplifiers:
• Only connected cabinets can be turned on, thanks to the sense circuit
in each cabinet jack plug that detects connected jacks. Green LEDs
indicate that cabinets are connected to the switcher.
• When a cabinet is selected and its jack is removed from the Switcher,
it turns into mute state.
• If there is a missing cabinet corresponding to the MIDI preset, the
Switcher turns into mute state.
• Each amplifier has a grounded input and a resistive load connected to
the output when not in use.
• The Switcher has a resistive load connected before the attenuator
input to protect against cable routing mistakes.
• Each amplifier is completely galvanically isolated, enabling the use of
any amplifier including bridged mono amplifiers.
!
!

MIDI implementation
The N-audio 8X7 and 4X4 Switcher has two ways to be controlled via
MIDI by preset mode and fixed Control Changes. In preset mode, you
select the desired amp and cabinets for any program change from your
MIDI controller, which is handy for live performance. Fixed Control
Change allows you to control each amplifier and cabinet individually
using a fixed CC, making it a better choice for studio use.
To select a MIDI channel, follow these steps
• While holding the MUTE button, power on the unit. The MIDI and
MUTE LEDs will start flashing sequentially.
• Release the MUTE button. A red LED will indicate the active MIDI
channel. Channel 1 is the default MIDI channel.
• Press one of the red buttons, which corresponds to a specific MIDI
channel.
• The selected MIDI channel will flash, followed by the power on
sequential LED lights.
NOTE: The N-audio 8X7 Switcher supports all 16 MIDI channels,
while the N-audio 4X4 Switcher only supports MIDI channels 1 through 9.
MIDI Preset Mode programming steps
• Select the desired cabinets and amplifier from their buttons.
• Press and hold the MUTE/MIDI button until the MIDI LED starts
flashing.
• Send a MIDI command from the MIDI controller. The MIDI LED will
stop flashing.
• Done. The preset is stored.
Deleting all stored MIDI presets
• Turn off the unit.
• While holding down the MUTE button, turn on the unit. The MIDI and
MUTE LEDs will start flashing in sequence.
• Release the MUTE button and press it again.
12345678910 11 12 13 14 15 16
MIDI channels
123456789
MIDI channels

• The MIDI LED will continue flashing followed by the startup LED
sequence lights.
All stored MIDI presets will be deleted.
If you want to cancel the preset mode procedure, press the
MUTE/MIDI button while the MIDI LED is flashing.
Fixed MIDI Control Changes
Each button on the N-audio Switcher can be controlled remotely via
fixed Control Changes. The table below shows the available control
changes.
NOTE: If a control change from the table above is sent when preset
mode is activated, the switcher cancels it and enables the specific device
if available.
NOTE: If a MIDI preset or control change from the table above is sent to
the Switcher and one or more cabinets from the preset are not connected,
their LEDs will flash and the Switcher goes to MUTE state.
8X7 Switcher
4X4 Switcher
CC#
Value
MUTE
MUTE
102
any
Amp 1
Amp 1
103
any
Amp 2
Amp 2
104
any
Amp 3
Amp 3
105
any
Amp 4
Amp 4
106
any
Amp 5
N/A
107
any
Amp 6
N/A
108
any
Amp 7
N/A
109
any
Amp 8
N/A
110
any
Attenuator ON
Attenuator ON
111
any
Attenuator OFF
Attenuator OFF
112
any
Cabinet 1
Cabinet 1
113
any
Cabinet 2
Cabinet 2
114
any
Cabinet 3
Cabinet 3
115
any
Cabinet 4
Cabinet 4
116
any
Cabinet 5
N/A
117
any
Cabinet 6
N/A
118
any
Cabinet 7
N/A
119
any

Tips for impedance limitations and impedance
mismatch in amplifiers
Impedance mismatch with tube amplifiers has been widely discussed,
and there is a lot of information available on what is and isn't possible.
Here are some quick tips and limitations to keep in mind regarding
impedance and impedance mismatch based on the type of amplifier.
Solid-state Amplifiers
Most solid-state amplifiers work with any impedance greater than 4
Ohm. However, they typically have a minimum listed impedance. Lower
impedance should be avoided! Increasing the impedance will reduce the
power output. It's generally recommended to use 4 or 8 Ohm cabinets,
but when using more than one cabinet simultaneously, the impedance
will decrease. In such cases, it's highly recommended to use 16 Ohm
cabinets. Bridged mono amplifiers and some modern class D amplifiers
can work with impedance as low as 2 Ohm, but this is not the case for all
other class AB amplifiers. Always refer to the amplifier manual for its
specific specs. A good practice when using solid-state amplifiers is to
keep the speaker cabinet impedance at or above 4 Ohm.
Tube Amplifiers
The tube amplifiers have an output transformer that match the output
impedance of the power tubes to the impedance of the connected
speaker. Impedance selectors on the back of most tube amplifiers offer
the flexibility to use different cabinets with varying impedances. It is
recommended to match the impedance of the amplifier and cabinet for
the best tone. Using mismatched impedance won't harm the amplifier but
will affect the tone slightly. To use an amplifier and cabinet with different
impedance, try to keep the impedance ratio within one step, such as 4
and 8 Ohm or 8 and 16 Ohm. Avoid using a 16 Ohm amplifier with a 4
Ohm or less cabinet.
Practical tips
When using more than one cabinet simultaneously, use 16 Ohm
cabinets with the 8 Ohm output of the tube amplifiers. If some impedance
mismatch occurs, keep the master level slightly below from its maximum
for safety. When the amplifier's output impedance is lower than the
speaker cabinet's impedance, it will increase the mids in the sound.
Conversely, if the amplifier's impedance is higher than the cabinet's
impedance, it will decrease the mids.

The table below summarizes different impedance matching and
mismatching restrictions for the tube amplifiers:
Tube Amplifier impedance Speaker cabinet impedance
4Ω8Ω16Ω
Acceptable
Perfect Not good
4Ω
4Ω8Ω16Ω
Acceptable Perfect
Not good
8Ω
16Ω
4Ω8Ω16Ω
Acceptable
Perfect
Acceptable
What is in the box
When you purchase the N-audio 8X7 or 4X4 Switcher, you will receive
a mains IEC cable and a user manual in the package. The 4X4 Switcher
comes with four rubber feet. However, please note that the 4X4 unit does
not include 1U mounting brackets as standard, but these can be
purchased separately if needed.
Technical specifications
Dimensions: 8X7 Switcher: 19" 1U rack W/H/D: 48/4.5/13cm
4X4 Switcher: W/H/D: 30/4.5/13cm
Weight: 8X7 Switcher: 2kg, 4X4 Switcher: 1.3kg
Mains Supply: Universal mains power supply 90-260VAC
Power Consumption: Max 10W @ 110VAC, Max 5W @ 230VAC
Warranty
N-audio 8X7 and 4X4 switchers comes with lifetime warranty.