Intellijel Pedal I/O 1U User manual

Pedal I/O 1U Manual
Pedal I/O 1U System
Effects Pedal Send/Return and High Impedance Instrument Input for Eurorack
Manual Revision: 2017.12.06

Pedal I/O 1U Manual
Table of Contents
Table of Contents
Overview
System
Features
Installation
Before Your Start
Powering Your Module
Connecting The Pedal I/O Jacks 1U Module
Connecting The Pedal I/O 7U Case Adapter
Front Panel (Pedal I/O 1U)
Controls
Inputs & Outputs
Front Panel (Pedal I/O Jacks 1U)
Inputs & Outputs
Technical Specifications
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Pedal I/O 1U Manual
Overview
Eurorack is a synthesist’s toy chest. Stompboxes are a guitarist’s toy chest. Each industry offers
a seemingly infinite variety of products that enable musicians to build systems unique to their
needs, and to create a signature sound. Each is also somewhat addictive. Rare is the musician
who doesn’t eventually need a larger toy chest to house the accumulated toys.
Fortunately for the budget conscious musician, Eurorack modules and stompboxes have always
existed in separate worlds — someone whose eurorack system consumes an entire wall in their
home is usually not the same person whose pedalboard now requires a dedicated roadie just to
transport it to the gig.
But those worlds have now collided. Thanks to the release of the Pedal I/O 1U system, Intellijel
has knocked down the barrier between eurorack and stompbox. This seemingly innocuous little
product is both a modular synthesist’s portal to stompbox nirvana, and a guitarist’s wormhole to
the sonic manipulations of eurorack modules.
The Pedal I/O 1U system enables the modular synthesist to interact with the impressive
assortment of delays, choruses, flangers, phasers, fuzz boxes, tremolos, wah-wahs, amp
simulators, compressors and pitch shifter pedals available to guitarists. Conversely, it also
grants guitarists access to the myriad filters, ring mods, wavefolders and — most importantly —
the near infinite CV modulation delights inherent in eurorack.
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Pedal I/O 1U Manual
System
A complete eurorack/stompbox solution requires the purchase of two components:
● A Pedal I/O 1U Module
The Pedal I/O 1U module houses all the
necessary gain and impedance-matching
circuitry, along with the ⅛” jacks required to
interface with eurorack modules. It also includes
the link cable for connecting one of the two ¼”
jack options outlined below.
● Either a Pedal I/O 7U Case Adapter, or a Pedal I/O Jacks 1U module.
Pedal I/O 7U Case Adapter
If you own an Intellijel 7U case (and if you wish to
use the case’s built-in ¼” jacks to connect the
guitar/stompbox) then you need the Pedal I/O
7U Case Adapter, which connects the Pedal I/O
1U module to the ¼” jacks. Since a 7U case has
two ¼” inputs and two ¼” outputs, you can
connect two Pedal I/O 1U modules to a single 7U
adapter.
Pedal I/O Jacks 1U Module
If you don’t own an Intellijel 7U case (or if you
prefer not to use its built-in ¼” jacks for pedal
interface purposes), then you need to purchase a
Pedal I/O Jacks 1U module, which connects
behind-the-panel to the Pedal Interface 1U
module, and provides a pair of ¼” in/out jacks for
connecting guitars or stompboxes.
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Pedal I/O 1U Manual
Features 
● Signals arriving at the Pedal I/O System through the RETURN jack (or from a 7U case’s
IN jack if using the Pedal I/O 7U Case Adapter) pass through a Class A triode emulator,
allowing for some tube-like overdrive at high gain setting.
● The Pedal I/O is more than just a simple level shifter — it’s also an impedance converter,
which provides proper drive and loading for any FX pedals or instruments you connect.
● Separate gain controls on both the SEND and RETURN. This enables you to adjust the
level of any audio being sent to the FX pedals as well as any audio coming back into the
modular. Not only does this allow you to optimize the signal-to-noise ratio, but by
significantly boosting the RETURN level, you can achieve some pleasingly overdriven
tones.
● Use the Pedal I/O’s RETURN circuit as a “direct box” for connecting any instrument.
● The high input impedance of the RETURN circuit allows it to be used as a piezo pickup
preamp for acoustic instruments.
● Use Pedal I/O in the studio as an active “re-amping” device to play pre-recorded tracks
back through guitar amplifiers or pedals.
● All inputs are protected for minimum RF interference.
● Low MIX output impedance for driving long cables, lower noise, and minimum
interference from outside sources.
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Pedal I/O 1U Manual
Installation
Intellijel Eurorack modules are designed to be used with a Eurorack-compatible case and power
supply.
Before Your Start
Before installing a new module in your case you must ensure your case’s power supply has
sufficient available capacity to power the module:
● Sum up the specified +12V current draw for all modules, including the new one. Do the
same for the -12 V and +5V current draw. The current draw will be specified in the
manufacturer's technical specifications for each module.
● Compare each of the sums to specifications for your case’s power supply.
● Only proceed with installation if none of the values exceeds the power supply’s
specifications. Otherwise you must remove modules to free up capacity or upgrade your
power supply.
You will also need to ensure you have enough free space (hp)  as well as free power headers in
your case to fit the new module.
You can use a tool like ModularGrid to assist in your planning. Failure to adequately power your
modules may result in damage to your modules or power supply. If you are unsure, please
contact us before proceeding.
Powering Your Module
When installing or removing a module from your case always turn off the power to the case and
disconnect the power cable. Failure to do so may result in serious injury or equipment damage.
Ensure the 10-pin connector on the power cable is connected correctly to the module before
proceeding. The red stripe on the cable must line up with the -12V pins on the module’s power
connector. The pins are indicated with the label -12V, a white stripe next to the connector, the
words “red stripe”, or some combination of those indicators.
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Pedal I/O 1U Manual
Most modules will come with the cable already connected but it is good to double check the
orientation. Be aware that some modules may have headers that serve other purposes so
ensure the cable is connected to the right one.
The other end of the cable, with a 16-pin connector, connects to the power bus board of your
Eurorack case. Ensure the red stripe on the cable lines up with the -12V pins on the bus board.
On Intellijel power supplies the pins are labelled with the label “-12V” and a thick white stripe:
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Pedal I/O 1U Manual
If you are using another manufacturer’s power supply, check their documentation for
instructions.
Once connected, the cabling between a module and power supply should resemble the picture
below:
Before reconnecting power and turning on your modular system, double check that the ribbon
cable is fully seated on both ends and that all the pins are correctly aligned. If the pins are
misaligned in any direction or the ribbon is backwards you can cause damage to your module,
power supply, or other modules.
After you have confirmed all the connections, you can reconnect the power cable and turn on
your modular system. You should immediately check that all your modules have powered on
and are functioning correctly. If you notice any anomalies, turn your system off right away and
check your cabling again for mistakes.

 
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Pedal I/O 1U Manual
Connecting The Pedal I/O Jacks 1U Module
The main Pedal I/O   module ships with a 3-wire link cable. Connect one end of this cable to the
Pedal I/O   module and the other end to either the Pedal I/O Jacks   module or the Pedal   I/O   7U
Case   Adapter   (one of which is needed to connect your external pedal’s ¼” jacks to your
eurorack modular).
If you purchased
the Pedal I/O Jacks
modules, simply
connect it to the
Pedal I/O   module
with the link cable
as shown to the
right.
The connectors are
keyed, so you can
orient them only
one way —
ensuring that you
can’t connect the
cable backwards. The Pedal I/O Jacks   does not require power, and the link cable is long
enough that the two module don’t have to be installed side-by-side if you don’t wish.
NOTE:   Never   use   the   3-wire   link   cable   to   connect   a   Pedal   I/O   module   to   an   Intellijel   Mixup
module.   Although   both   modules   use   this   same   cable/connector   —   they   serve   different   purposes
and   carry   different   signals.

 
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Pedal I/O 1U Manual
Connecting The Pedal I/O 7U Case Adapter
The main Pedal I/O   module ships with a 3-wire link cable. Use this to connect the Pedal I/O
module to either the Pedal I/O Jacks   module or the Pedal   I/O   7U   Case   Adapter   (one of which is
needed to connect your external pedal’s ¼” jacks to your eurorack modular).
If you purchased the
Pedal I/O 7U   Case
Adapter  , simply connect it
to the Pedal I/O   module
with the link cable as
shown to the right. Note
that you can connect two
Pedal I/O   modules to a
single Pedal I/O 7U   Case
Adapter   (since there is a
pair if ¼” I/O jacks on the
7U case).
Next, plug the Pedal I/O 7U   Case
Adapter   into the your case’s
built-in Audio I/O   board, making
sure to align the white lines on
the two boards:
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Pedal I/O 1U Manual
Front Panel (Pedal I/O 1U)
Controls 
A. SEND LEVEL knob - Adjusts the level of the signal arriving at the Pedal I/O’s IN jack
before it’s sent out of your modular and into your FX pedals (by way of either the ¼”
SEND jack on the Pedal I/O Jacks, or a ¼” OUT on a 7U case fitted with the
Pedal I/O 7U case adapter).
B. RETURN LEVEL knob - Adjusts the signal level coming back into the modular from your
external effects pedals, or from an instrument plugged directly into either the ¼”
RETURN jack on the Pedal I/O Jacks, or a ¼” IN on a 7U case fitted with the
Pedal I/O 7U case adapter.
C. CLIP Indicator LED - This LED monitors the signal level coming back into the modular
from either your external effects pedals, or from a connected instrument input. It lights
slightly before clipping, giving you a bit of headroom before actual clipping occurs. This
lets you maximize levels by allowing the CLIP LED to light occasionally on the highest
peaks. But as with all things musical — use your ears as the deciding factor!
D. MIX (DRY/WET) knob - Determines the wet/dry balance of the signal sent to the
module’s MIX output. Fully counterclockwise, only the DRY (unprocessed) signal is
heard in the MIX. Fully clockwise, only the WET (processed) signal is heard in the MIX.
At the noon position, equal amounts of WET and DRY appear in the MIX.
NOTE:   Not   every   pedal   is   designed   to   have   its   input   signal   mixed   in   with   its   output.
Some   (for   example,   phase   shifters)   may   return   a   signal   that   is   out   of   phase   with   the
original   audio,   so   balancing   the   Wet   &   Dry   levels   could   result   in   phase   cancellation.   In
such   cases,   you’ll   probably   want   to   set   the   MIX   knob   to   maximum   wetness.
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Pedal I/O 1U Manual
Inputs & Outputs
1. IN - Connect the audio signal you want processed by your external pedals to the IN jack.
Modular-level audio arriving at this jack is converted to instrument-level audio and
impedance-matched before it’s sent to either the Pedal I/O Jacks’ SEND jack or to one
of the 7U case’s ¼” OUT jacks (if fit with a Pedal I/O 7U Case Adapter).
2. MIX - Any audio that’s returned from your FX pedals is converted back to modular-level
and impedance-matched prior to appearing here at the MIX jack. If you plug a guitar or
other instrument into the Pedal I/O Jacks’ RETURN jack (or into one of the 7U case’s ¼”
IN jacks if fit with a Pedal I/O 7U Case Adapter), then the modular-level and
impedance-matched signal from that instrument appears at the MIX jack.

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Pedal I/O 1U Manual
Front Panel (Pedal I/O Jacks 1U)
Inputs & Outputs
1. SEND - Connect a ¼” instrument cable from the SEND jack to the input of your external
FX pedal. The audio coming out the SEND jack is an instrument-level &
impedance-matched version of the modular-level audio signal you connected to the
Pedal I/O   module’s IN jack.
NOTE:   This   is   an   unbalanced   TS   cable   (standard   for   guitars   and   FX   pedals),   though   you
can   use   TRS   cables   —   you   just   won’t   get   any   benefit   from   doing   so.
2. RETURN - Connect a ¼” instrument cable from the output of your external FX pedal to
the RETURN jack on this module. The audio arriving at this jack is impedance-matched
and converted to modular-level by the Pedal I/O   module, where it’s then made available
at that module’s MIX jack.
You can also plug a guitar or other instrument directly into the RETURN jack and
process it with your modular synth. This is a high impedance input, allowing the
Pedal I/O system to act as a piezo pickup preamp for acoustic instruments. Audio
arriving at the RETURN jack passes through a Class A triode emulator (enabling
anything from clean to tube-like distortion) and an impedance converter and level shifter
to insure full integration in a modular synth environment.
NOTE:   This   is   an   unbalanced   TS   cable   (standard   for   guitars   and   FX   pedals),   though   you
can   use   TRS   cables   —   you   just   won’t   get   any   benefit   from   doing   so.
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Pedal I/O 1U Manual
Technical Specifications
Pedal I/O IN jack:
● Input level = 0 dBV nominal, +17 dBV max
● Input impedance = 60 KΩ
● Gain = -30 dB to -20 dB
● RF filter protected
Pedal I/O Jack SEND (or 7U Case Adapter OUT):
● Output level = -20 dBV to -30 dbV nominal based on Send Level
● Output impedance = 12 KΩ to simulate the impedance of magnetic guitar pickup
Pedal I/O Jack RETURN (or 7U Case Adapter IN):
● Input level = -20 dBV to -30 dBV nominal based on Return Level
● Input impedance = 1 MegΩ
● Return Gain = fully off to +30 dB
● RF filter protected
Pedal I/O MIX jack:
● Output level = 0 dBV nominal, +17dB max
● Output impedance = 100Ω
● Frequency response is 20Hz to 22KHz
● THD = 0.002% to 0.085% at Vin = 0dBV to +17dBV
(Pedal In to Pedal Out, Mix = effect, Return Level = min, Send Level = max)
THD = 0.04% to 4.0% at Vin = 0dBV to +17dBV
(Pedal In to Pedal Out, Mix = effect, Return Level = max, Send Level = max)
Pedal I/O Width
Pedal I/O Jacks Width
16 hp
8 hp
Pedal I/O Maximum Depth
Pedal I/O Jacks Depth
29 mm
44 mm
Current Draw
10 mA @ +12V
10 mA @ -12V
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