E-RM midiclock User manual

Manual
midiclock
Function, Utilization and technical Details

00 – Box contents
01 – Hello!
02 – Quick Start Guide
03 – Function Overview
3.1 – User Interface
3.2 – Modes of Operation
04 – Hints for Synchronisation with MIDI clock
05 – Technical Details
5.1 – Electrical Properties, Dimensions and Weight
5.2 – MIDI command Reference
06 – Operating Notes
07 – Declaration of Conformity
08 – Contact
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03
04 - 05
06 - 09
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11 - 13
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15
16 - 17
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Simply play together.

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Included in the box are a midiclock, a USB cable (1.8m, A/B ) and this
manual.
00
Box contents
01
Hello!
Congratulations for purchasing your midiclock. With this tool you are
able to completely control the tempo of your live-sets, your perfor-
mance or improvisation.
It's easy now to sync multiple DAWs and sequencers with a uniquely
low jitter, control the tempo, and start and stop your gear whenever
you want. The midiclock opens up new possibilities for you to interact
with other artists.
Please read this manual carefully and follow the advice to be rewarded
from the beginning with a great and powerful tool!
Have fun and simply play together,
Maximilian Rest & Rudolph Maier

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02
Quick Start Guide
To get started with the midiclock, you need at least a sequencer, a
computer running a software-sequencer or any other instrument that
is able to sync to a MIDI clock signal.
Connect the devices as pictured. Set them into MIDI slave mode accor-
ding to their respective manuals if necessary so that they can sync to
MIDI clock.
USB
USB/FW
Computer
If you use a software-sequencer, please adjust the correct settings to
compensate the latencies. For further information, please consider
chapter 04 - 'Hints for synchronisation with MIDI Clock'. Set your
required tempo with the rotary encoder and conrm by pressing it
down. If all devices are connected and ready for playback, you can start
by pressing 'Play/Pause'.
MIDI Interface
MIDI OUT
MIDI OUT
MIDI IN
USB/FW
USB
MIDI IN Sequencer

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03.1
User Interface
01
Display & LEDs
The display shows the current tempo in beats per minute.
The upper LED M shows the operating mode.
When lit, the 'Live' mode is active, otherwise the midiclock is in its
'Normal' mode. During playback the lower LED ashes with
the beat. It is constantly lit when paused and turns o if all devices are
reset at the next beginning of a playback.
02
Rotary encoder
The rotary encoder is used to set the tempo. The respective function
depends on the current operating mode: In the 'Live' mode, tempo
changes are applied immediately. In the 'Normal' mode, the tempo is
only changed if you press down the encoder after your setting. You can
switch between both operating modes by double-clicking the encoder.
LED
rotary encoder
display
02
01

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03
Play/Pause - Button
This button starts and stops all connected devices if they support
'MIDI Start', 'MIDI Stop', and 'MIDI Continue' commands. After pressing
the button at the beginning of a session the song position of all slaves
is reset to the beginning and the clients are started. During playback,
'MIDI Stop' and 'MIDI Continue' are sent alternately.
04
Resync/Reset - Button
If pressed during playback, this button causes a reset of the song
position pointer in all connected devices at the beginning of the next
bar, followed by 'MIDI Start'. With this feature you are able to re-sync
slaves during playback without interruption.
If it is pressed while the playback is paused, it acts like a 'Stop' button.
If you now press 'Play' again, all devices start their playback from the
beginning.
03.1
User Interface
Resync/Reset - button
04
Play/Pause - button03

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03.2
Modes of Operation
The midiclock has two modes of operation that are indicated by the
LED and the display brightness.
If the LED is o, the midiclock is in the 'Normal' mode. In the 'Normal'
mode, it is intended to be used as a stable clock generator that works
in the background. If you change the tempo by turning the rotary
encoder, the midiclock displays the new tempo and you can conrm it
within a timeout of two seconds by pressing down the encoder. If you
do not conrm it in time, the changes will be discarded and the actual
tempo is displayed again. In this mode, accidental adjustments won't
aect the tempo of your performance.
You can change the operating mode by double clicking the encoder.
When the LED is lit permanently, the midiclock is in 'Live' mode. The
'Live' mode is useful if you want to be able to change the tempo at any
time during the playback. In this case the tempo changes are applied
immediately and without conrmation. During 'Live' mode, the BPM
shown in the display is always the actual tempo.
You can always get back into the 'Normal' mode by double-clicking the
encoder again.
04
Hints for Synchronisation
with MIDI clock
Synchronising multiple MIDI devices is a known topic for almost any
electronic musician. The midiclock is an essential tool for a low-jitter
sound setup, but please keep in mind, that also the midiclock cannot
compensate all the malfunctions of other devices. There are numerous
manufacturers that make MIDI capable devices, but not all of these
instruments are able to react immediately and precisely to MIDI clock.
There are two main problems that a MIDI slave has to solve, especially
a DAW:
First, it needs to take care of the synchronisation of the tracks to the
master clock.
Second, it should implement functions like 'start', 'pause' and 'stop'.
These actions should be applied immediately and without any delay
or run-out time.

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04
It is technically possible to synchronise a system to a jittering external
clock source. To be prepared for jitter, some products make use of
complex signal processing.
With a PLL for example, it is possible to manage dicult clock signals.
That implies that the slave calculates an average value for the tempo
to compensate the jitter. This calculated moving average is then used
for the playback. This average tempo is continuously refreshed by the
incoming clock ticks but the playback is freewheeling on the calculated
BPM. Sometimes you can observe that the song position is not based
on the counted beats, but on the calculated tempo and the elapsed
time.
Moreover, most devices for electronic music production are equipped
with a buer for the sound output.
These buers cause constant latencies that have to be merged with
the playback time. It depends on the implementation what happens
when a 'stop' command is received. Sometimes you can recognize
some sort of a run-out time. In this run-out time the data in the audio
buer is played till the end and the playback does not stop immedia-
tely. This causes that some sequencers do not stop instantly with the
arrival of the 'stop' command, but with delay of the buer. If now the
master does not dene a new song position, the slaves are shifted to
each other on a 'continue' command. In this case all slaves run with the
same tempo, but not in sync with the beat.
Please consider the following hints to prevent those problems:
First, use a sound card with a small buer size if you use DAWs and
software-sequencers.
Furthermore, a professional MIDI interface is essential for good
results.
Avoid merging midiclock signals with MIDI commands from other
sources, since you cannot ensure beat accuracy in this case..
It is possible that you still notice shifted tracks after pausing. In this
case you can get around this by sending a 'MIDI song position pointer'.
The midiclock sends this pointer at the beginning of playback and
re-sync, but not on 'MIDI continue'.
That's the only way to ensure that all slaves are situated at the same
song position and start in sync.

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05.1
Technical details
Electrical Properties
MIDI OUT
The midiclock has two MIDI ports (DIN, 5-pole). They provide a current
loop and are designed for opto-coupler driven slaves, like documented
in the MIDI specs. The no-load voltage is 3.3V, the short-circuit current
is 20mA.
Power
The USB port (Type B) acts only as a power supply. You can use either
a computer or an external power adaptor. The power consumption is
max. 75mA at 5V when used properly.
Please note that the input voltage must not exceed 7V under any
circumstances.
Dimensions and Weight
The dimensions with knob and rubber feet are 48mm high, 95mm long
and 62mm wide. The weight is 235g without cable.
05.2
Table of MIDI commands
The midiclock uses the following MIDI commands to synchronise and
control all connected slaves:
The MIDI clock command (0xF8) is always being sent when a power
supply is connected. The jitter is 0.1µs on average, the maximum devi-
ation is 0.46µs.
Function MIDI command
Synchronisation MIDI clock: 0xF8
Start Song Position Pointer: 0xF2, 0x00, 0x00
MIDI start: 0xFA
Pause MIDI stop: 0xFC
Continue MIDI continue: 0xFB
Reset like 'Start'
Resync like 'Start', but on the next downbeat

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06
Operating Notes
Please note the following advice to help you
enjoy your midiclock. Failure to observe may void
your warranty.
Use a soft and clean cloth to wipe your midiclock. Do not use any deter-
gents on the surface.
Do not expose your midiclock to temperatures below -10 °C (14 °F) or
above 60 °C (140 °F) and avoid direct sunlight.
If you face a high dierence in temperature during transport, wait a
sucient time before you use your midiclock. Otherwise there may be
condensation which can destroy the electronics inside.
The midiclock must not be used in wet environments and the ingress of
any uids must be avoided.
Usually, the power is supplied by a computer USB port. If you want to
use a wall plug, be sure to meet the electrical specications!
Damages, which are caused by third party wall plugs are not included
in any warranty. You also void your warranty with rough handling,
excessive strain, manipulation, mechanical or chemical inuences, as
well as damage due to other reasons that we are not responsible for.

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07
Declaration of Conformity &
Disposal Note
It is hereby con rmed, that the midiclock meets
all rules and regulations regarding EU-directive
2004/108/EG for electromagnetic compliance to
protect humans and the environment.
The midiclock is compliant with the RoHS directive.
If you wish to dispose your midiclock, please contact
your local dealer for recycling. Do not put it in your
household waste.
RoHS
08
Contact
We, that is Er ndungsbüro Rest & Maier, made the midiclock meet
our own high expectations on value and functionality of a product. If
you have any questions or suggestions, do not hesitate to contact us.
A small production batch for professional users makes it possible to
adapt to your personal requirements.
Erfi ndungsbüro Rest & Maier GbR
[email protected]
www.midiclock.de

Composition and Layout: Aaron Winter
Contributing editors to the English version: Matthew Thomas and Kathrin Schalper
Erndungsbüro Rest & Maier GbR – Berlin, 2013
www.midiclock.de