Full Text Searchable PDF User Manual

WAV Recorder
4ms Company
User Manual 1.0.1 – June 27, 2018
for f
irmware v1.0
The
WAV Recorder
from 4ms Company is a high fidelity, two-channel stereo audio recorder with basic playback
features. Accepting a wide range of input signals, from line-level to modular-level, the
WAV Recorder
stores
audio onto a microSD card in lossless .wav format up to 96kHz/24-bit. The trigger jack can be used for capturing
rhythmic loops or synchronizing multiple
WAV Recorder
modules for multi-track recording. In
Playback
mode,
the trigger jack or button plays the most recent recording. A simple file/folder navigation system can be used to
browse the folders on the card for playing back .wav files. A
Gain
knob allows for up to +20dB of boost, and an
LED Signal Meter indicates clipping and the signal level.
• Records up to 96kHz/24-bit, creating stereo or mono .wav files on the microSD card
• Gain knob and LED level meter make it easy to record a wide range of signal levels
• Plays standard .wav files from the card, without renaming files
• Browse any folder on the card for playback
• Card can be hot-swapped without rebooting module
• Extremely low noise, high-fidelity design
• Includes 16GB microSD card (Class 10), SD adaptor, 10-to-16 pin power cable and M3 screws
• Can be used as a stereo pre-amp (line to modular level), providing up to +20dB of gain
Record
WAV RECORDER
Left
Right
IN
OUT
Clip
Input Gain
Busy
Playback
Record
0dB
-
∞
+20dB

Table of Contents
Setting up your WAV Recorder
1. Power your Eurorack modular case off and find 6HP of available space.
2. Connect the free end of the power cable to a 16-pin Eurorack power header on
your power supply distribution system, with the red stripe towards to the -12V.
The other end of the power cable is a 10-pin connector which should already be
connected to the WAV Recorder with the red stripe on the power cable orientated
towards the bottom of the module.
Note: The
WAV Recorder
is reverse-polarity
protected, but other modules being incorrectly connected could damage
anything on the power bus.
3. Using the included Knurlie screws, securely fasten the
WAV Recorder
to the rails
of your case.
4. Power the system on.
5. Begin with
Tutorial: Basic Recording
on page 4 of this manual.
Setting up your WAV Recorder
2
..............................................................................
Controls: Button, Knob, Switch and Jacks
3
............................................................
Tutorial: Basic Recording
4
.......................................................................................
Folders and File Organization
5
................................................................................
Playback
5
................................................................................................................
Browsing Files for Playback
6
...................................................................................
Trigger Jack
7
...........................................................................................................
Pausing Recording
7
.................................................................................................
Example Patch: Multi-track Recording
8
..................................................................
Using the WAV Recorder as a Pre-amp
9
.................................................................
Busy Light
9
..............................................................................................................
Checking for Free Space
9
.......................................................................................
Hot Swapping the microSD Card
10
........................................................................
LED Signal Meter and Clipping
10
............................................................................
Recording For Long Periods
10
................................................................................
System Mode
11
.......................................................................................................
Recording Rates and Selecting microSD Cards
12
..................................................
Checking the Firmware Version
13
...........................................................................
Updating Firmware (Audio Bootloader)
13
...............................................................
microSD Card
14
......................................................................................................
Electrical and Mechanical Specifications
15
............................................................
Jumpers
15
...............................................................................................................
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Important!
Never remove the microSD card when the
Busy
light is on. This could corrupt the files on
the card.
If you remove the
Wav Recorder
from your
case, a
lways
store and transport it in the
included anti-static bag.

Controls: Button, Knob, Switch and Jacks
Record/Playback switch
The
WAV Recorder
has two main functions: recording and playing .wav files. This switch
toggles between these functions.
Flip the switch up to enter
Record
mode. Flip the switch down to enter
Playback
mode.
Button
In
Record
mode, press the button once to start recording a new .wav file onto the card. Press
it again to stop recording. The button will turn red while recording.
In
Play
mode, press the button once to play the currently selected .wav file from the card.
Press it again to stop playing. The button will turn green while playing.
Audio IN jacks
Patch the audio signal you want to record into the
IN
jacks. The jacks are normalized so that
if you patch a mono signal into the
Left IN
jack and have nothing plugged into the
Right IN
jack, the signal will be routed to both channels. To record a stereo signal, patch into both
Left
IN
and
Right IN
jacks. These jacks accept a wide range of signal levels, from line level up to
modular level.
Audio OUT jacks
The
Audio OUT
jacks can be used for monitoring the signal while recording and for listening
to playback of .wav files. The
Left OUT
jack outputs the left channel, and the
Right OUT
jack outputs the right channel. The Signal Meter
shows the level of the signal present on
these jacks.
Signal Meter
These eight lights will show the level of the signal being output on the
OUT
jacks. If you are
recording, this is equivalent to the signal being recorded. The left column represents the left
audio channel, and the right column represents the right audio channel. More lights turned on
means there’s a louder signal. The top red lights indicate clipping. If the Signal Meter shows
that your signal is either too loud (clipping) or too quiet, you can use the the
Gain
knob to
adjust the level.
Gain knob
The volume (level) of the signal being recorded or played can be adjusted using this knob.
Turning the
Gain
knob up will make the output louder, while turning it down will make the
signal quieter. When the knob is turned all the way to the left, the signal is muted. When the
knob is pointed directly up, the signal is neither boosted nor cut. When the knob is turned all
the way up, +20dB of gain is applied (which is enough to boost a line level signal to a
modular level signal).
Record Trigger jack
This jack accepts a trigger. In
Record
mode, a trigger signal will toggle recording. In
Play
mode, a trigger will make playback start or re-start. The
Record Trigger
jack allows you to
connect and synchronize your
WAV Recorder
with a clock, other
WAV Recorders
or other
modules. It also allows you to remotely control recording and playback.
SD Card slot and Busy Light
The
WAV Recorder
records and plays back from a microSD card inserted into the card slot.
Insert the end of the card with the shiny pins facing to the left.
The
Busy
light will turn on whenever the card is being read or written.
NEVER REMOVE THE SD CARD OR POWER OFF WHEN THE BUSY LIGHT IS ON!
Always wait until the light is off. The light will turn off after you stop recording or playing.
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Playback
Record
Left
Right
IN
OUT
Clip
Input Gain
0dB
-
∞
+20dB
Record
Busy

Tutorial: Basic Recording
Recording on the
WAV Recorder
is easy!
1. Find something you want to record. It can be audio from your modular, another synth or musical
instrument, your phone or computer, or anything that outputs a line-level, headphone-level, or
modular-level signal.
2. Patch the audio signal into the
Left IN
jack. If you have a
stereo signal, you can patch the right channel into the
Right IN
jack.
3. Patch the
OUT
jacks to something that lets you hear the
audio (speakers, amp, or a mixer).
4. The lights on the
Signal Meter
should be responding to the signal you patched in. Turn the
Gain
knob so that some lights turn on, but not so high up that the red lights turn on. You should also
hear the audio output change volume as you turn the
Gain
knob.
5. Make sure the switch is flipped to
Record
and press the button. The button will turn red, and the
Busy
light will start to flash.
6. Record as much as you want and then press the button again. Wait for the
Busy
light to turn off.
7. Congratulations! You just made a high-quality recording!
The
WAV Recorder
has now created a .wav file on the microSD card. You can listen to your recording
by flipping the switch to
Playback
and then pressing the button. The button will turn green and you’ll
hear your recording. You can press the button again to stop playback.
You also can listen to the recording on your computer. Wait until the
Busy
light has turned off and then
pull out the microSD card. Insert it into your computer or card reader and browse the
WAV Recorder
folders for the folder and file with the highest number. See the
Folders and File Organization
section for
more details.
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15
Tip:
Use an adaptor cable to convert to
1/8” (3.5mm) if necessary. You can
patch a stereo cable into the
IN
jacks, but the right channel will be
ignored.

Folders and File Organization
Every time you power on the
WAV Recorder,
a new session is started. All of the recordings you make
in each session are saved in the same session folder. Session folders are named like this:
WAV Recorder - 0001
WAV Recorder - 0002
The most recent session folder will always be the highest
numbered folder.
Inside each folder are your recordings, named in numerical
order:
001 - recording.wav
002 - recording.wav
Once it reaches
999 - recording.wav
, it’ll automatically
create a new session folder and start over at
001
.
The most recent recording will always be the highest
numbered file in the highest numbered folder.
If the system gets powered down unexpectedly while recording
(and luckily it happens while the
Busy
light is off), you might find
your recording in the
_tmp
folder.
Note: This naming system is what the
WAV Recorder
uses when
you make a new recording. In
Playback
mode, any file with any name can be accessed. You do not
need to rename your files to play them.
Playback
Playing .wav files with the
WAV Recorder
is easy.
Flip the switch to
Playback
and press the button. The most recent recording will play. The button will
turn green while a recording is playing. Turn the
Gain
knob to adjust the playback volume. You can
press the button again to stop playback, or it will stop by itself when the .wav file has finished playing.
If you haven’t recorded anything yet this session, but you’ve made previous recordings, the the
WAV
Recorder
will play the most recent recording it finds (the highest numbered file in the highest
numbered session folder on the microSD card). See
Folders and File Organization
for an explanation
of the naming system. If no session folders are found, the
WAV Recorder
will pick the first .wav file in
the first folder on the microSD Card, alphabetically.
You’re not stuck with only playing the most recent recording! Use the browsing feature to choose a
different file in a different folder. See the next section for details.
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Browsing Files for Playback
When you first flip the switch to
Playback
, the most recent recording in the most
recent session folder will be selected as the current playback file. If there are no
session folders on the card, then the folders will be scanned alphabetically and the
first file in the first folder will be selected.
Hold down the button while turning the knob to browse the folder of the currently
selected file. As soon as you start turning the knob with the button down, the lights
will show you how many files are in the folder. Any light that’s turned on represents
a file in the folder. For example, if six lights are on, then there are six files in the
selected folder. The files are in alphabetical/numerical order.
The light corresponding to the currently selected file will be brighter than the others. As you turn the
knob( while still holding the button down), the bright light will move through all the available files. See
diagram below.
If you want to hear the new file that you've
selected, you can play it like you would play any
other file: just tap the button or fire a trigger into
the jack. If you’re playing a long file, you can
continue to browse while the file is playing without
interrupting it. As long as you are holding the
button down while turning the knob, the playback
volume won’t change.
Folders with lots of files
If there are more than eight files in a folder, then
the files will be split up into “pages” of eight files
each. The first and/or last light will flicker a bit to
indicate there’s another “page” of files before or after it. The
number of flickers indicates the next or previous “page”
number (i.e, one flicker means you can access the 1st page
by turning past that light, two flickers means the 2nd page
is past that light, etc…) Turn the knob to the first or last
light, and then keep turning it a little bit more to jump to the
next or previous page. The light will jump from the first to
last position, or vice-versa, when you change pages.
Browsing to a new folder
If you want to select a file in a different folder,
press and hold the button while turning the knob
just like you do for file selection. Turn the knob all
the way up (to access the next folder) or all the
way down (to access the previous folder), and
leave it there for about two seconds (while still
holding the button down). The four lights on the
left or right column will flash rapidly to tell you that
you’re about to go to the previous or next folder,
respectively. Release the button when you see the
flashing, and you will jump to the next or previous
folder. The folders are browsed alphabetically/
numerically.
If you see the column lights flashing, but don’t
want to change folders, turn the knob up or down to cancel the action.
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…and turn
Playback
Record
Hold…
Clip
Current
File
Other
Browsing a folder containing 6 files:
Tip
:
If you can’t quite reach the top or
bottom file, just let go of the button,
turn the knob to a new position,
and then resume the button+knob
motion. This will also change the
playback volume, so another
technique is to turn the knob
rapidly to advance by more files.
Clip
Hold 2 sec., then release
+
Go to Previous Folder
Clip
Hold 2 sec., then release
+
Go to Next Folder

Trigger Jack
In
Record
mode, the
Record Trigger
jack can be used to synchronize the starting and/or
stopping points of a recording: simply patch a trigger or gate into this jack. When a trigger or
rising edge of a gate is received, recording will start (if it’s not already started) or stop (if it’s
not already stopped). There are several uses for this:
Multi-track recording
Using two or more
WAV Recorder
modules, you can patch the same trigger into all of the trigger
jacks. Firing a trigger will start recording on all units simultaneously. Since each module is a two-track
recorder, the number of tracks you can record will be twice the number of modules: two
WAV
Recorders
can function as a four-track recorder, three
WAV Recorders
can
function as a six-track
recorder, and so on…
Combining the .wav files from the microSD cards on all of your units is easy to do with most audio-
editing software packages. For example, the freely-available program Audacity can combine stereo
recordings by copy/pasting the individual stereo tracks into one multi-track file.
See the
Example Patch: Multi-track Recording
.
You could even combine tracks in a computer-free environment by using a mixer to combine the
playback outputs of all the
WAV Recorders
which were used to make the recording. Feed the stereo
output of the mixer to an additional
WAV Recorder
and record the mix-down “live”.
Recording timed loops
If you have a rhythmic patch, you can feed a slow clock into the trigger jack to record a “bar” or
“measure” of the patch. If you just want to capture just one measure, plug in the trigger while the clock
gate is low. When the clock goes high, recording will begin on the start of the measure (assuming your
clock is synced to the start of the measure). When the next measure starts, the clock will go high again
and cause the recording to stop, create a recording that’s exactly one measure long. If you’re making
variations to the patch as it plays, you can keep recording more measures to capture a variety of
loops.
Once the recording is stopped (the button is not lit up), flip the switch down to
Playback
. When the
next trigger fires on the next measure, your loop will play in time. This technique allows you to create a
new loop while the old one is playing (you’ll need to route/split/mix your signals in way that you can
independently adjust the level of the
WAV Recorder
’s output and your source audio). You can even
use the file browsing techniques to go between different variations of the loop you captured (see
Browsing Files for Playback
section).
Pausing Recording
If you start recording and then flip the switch to
Playback
, the recording will be paused. The button
flashes red to indicate recording is paused. You’ll continue to hear the audio pass through, but it won’t
be recording. To continue recording, flip the switch up to
Record
and then press the button again. It’ll
turn solid red to show that you’ve resumed recording.
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Record

Example Patch: Multi-track Recording
Six-track recording
The diagram above shows how you can use multiple
WAV Recorder
modules to record more than two
tracks at a time. A common trigger can start and stop all the recordings at the same time. The trigger
can be from a touch pad or any module that generates a manual gate or trigger. Using a passive mult,
active mult, or stacking cables, split this trigger signal and run it to all the
Record Trigger
jacks.
Patch your audio signals into the
IN
jacks on the
WAV Recorders.
Check that the switch is set to
Record
on all the modules, and remember to refresh any cards that you’ve recently inserted. You also
may wish to verify the recording rate settings and set all the modules to the same values.
Turn all the
Gain
knobs to the same position unless you have a reason to record some channels louder
than others. When you’re ready to record, fire the trigger to start recording. When you’re done, fire
another trigger to stop. Copy the .wav file from each of the microSD cards onto a computer and
combine the files into a multi-track file using any audio-editing software.
High precision phase alignment
For most purposes, the files can be combined simply by snapping the beginnings to the same point.
However, if you are doing some specific work that requires the phase differences between tracks to be
exact, then you may need to line up the tracks manually. In our tests, a typical difference was between
340uS and 1.7ms (15 to 75 samples at 44.1kHz). This is well under the perceivable latency threshold
of human hearing. If your project requires a tighter tolerance than this, we recommend beginning the
recording with a “clap” or some signal common to all tracks: this will make it easy to see how far to
adjust each track along the time axis.
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Record
WAV RECORDER
Left
Right
IN
OUT
Clip
Input Gain
Busy
Playback
Record
0dB
-
∞
+20dB
Record
WAV RECORDER
Left
Right
IN
OUT
Clip
Input Gain
Busy
Playback
Record
0dB
-
∞
+20dB
Record
WAV RECORDER
Left
Right
IN
OUT
Clip
Input Gain
Busy
Playback
Record
0dB
-
∞
+20dB
Trigger (start/stop
Audio channel 1
Audio channel 2
Audio channel 3
Audio channel 4
Audio channel 5
Audio channel 6
OUT jacks can be used
for monitoring (optional)

Using the WAV Recorder as a Pre-amp
Since the
WAV Recorder
can provide a wide range of gain or attenuation to stereo signals, it can also
be used as pre-amp to interface external equipment with Eurorack modules.
Patch any line-level, headphone-level, or modular-level signal into the
IN
jacks and turn the
Gain
knob
until you see some signal but no clipping. The signal on the
OUT
jacks will now be at standard
Eurorack audio signal levels and can be patched to any other Eurorack module.
For example, if you wanted to use your Eurorack modular system to process an online live stream from
your smart phone, you could patch the phone directly into the
Left IN
jack using a mono or stereo
cable. (If you want to get a stereo signal from the smart phone, use a stereo-to-mono adaptor and
patch into the
Right IN
jack as well.) Turn the volume up on the smart phone, and turn the
Gain
knob
so that you see some blue lights. You can now patch the
OUT
jacks to any other module that works
with normal Eurorack audio signals.
Note: The WAV Recorder does not work with microphones that require voltage from the pre-amp.
Busy Light
The microSD card is safe to remove if you stop recording and wait until the
Busy
light turns off. If
you’re in
Playback
mode and not currently playing anything, it’s also safe to remove the card. It’s
not
safe to remove it while
Paused
(you’ll lose the file you recorded).
You can corrupt the files on your microSD card if you pull it out while the
Busy
light is on. This is similar
to unplugging a USB thumb drive or external hard drive from your computer while copying files. You
might get lucky and keep your files; but, if the card starts to act weird, do a disk repair or “first aid”
using Disk Utility on MacOS or fsck (or something similar) on Linux. After repairing the disk, copy all
your files off, format it in ExFAT, and copy your files back on. Always keep backups of important files!
Checking for Free Space
You can check the amount of free space on the card by holding the button down
for 2 seconds while in
Record
mode. An animation of the lights will display while
the card is being scanned. Once the lights stop animating, the number of lights
that are off will show how many hours of free space you have available.
If there
are 8 or more hours of recording time available, all the lights will turn off when the
animation stops.
For example, let’s say you hold down the button and the animation stops with five lights on and three
off (see diagram below):
The fact that there are three lights off means that there are three to four hours of
recording time available on the card.
Changing recording settings will change the amount of time available. If you went
into System Mode and changed to mono recording, the next time you check for
free space it will show six lights off (six hours mono = three hours stereo).
Checking for free space serves a dual purpose: if you insert a microSD card into the module while it’s
powered on, the card will need to be mounted before it can be used for recording or playback.
Checking for free space will mount the card safely and report the free space available. See
Hot
Swapping
(next section).
If the card is ever detected as being full (or having less than 50MB in available storage), all 8 lights will
flash brightly twice when you press record. The lights will keep flashing every 5-10 seconds until you
flip to
Playback
mode or insert a new card and refresh it.
Note:
The
WAV Recorder
will always leave about 50MB available for swap space.
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Clip
Hold 2 sec
Playback
Record

Hot Swapping the microSD Card
As long as the
Busy
light is off, it is acceptable to remove the microSD card (and put it into a
computer to check the files, etc) without powering down the
WAV Recorder
. You can even re-insert a
different card.
When you reinsert the microSD card into the
WAV Recorder
while the module is powered on, you
must re-mount it (refresh it) by holding the button down for 2 seconds while in
Record
mode. This will
display an animation which shows how much available space is on the card (see
Checking for Free
Space
section). After the animation is complete, the card is ready for recording and playback.
If you forget to refresh a newly inserted card and try to start recording or playing immediately, the
WAV
Recorder
will attempt to re-mount the card before recording or playing. This can cause a delay and
sometimes a “hiccup” in playback or recording.
You do not need to refresh a card if it’s already inserted when you power up the
WAV Recorder
. The
module always mounts the current card as part of its normal boot-up sequence.
LED Signal Meter and Clipping
The LED Signal Meter shows the output signal level:
-0.4dBFS
(20Vpp): The red LEDs turn bright solid (clipping)
-2.6dBFS
(16Vpp): The red LEDs turn on dimly
-8dBFS
(8.5Vpp): The white LEDs turn on
-12dBFS
(5Vpp): The upper blue LEDs turn on
-21dBFS
(1.75Vpp): The lower blue LEDs turn on
The Signal Meter shows the actual signal present on the output jacks-whether you are recording or
playing. By adjusting the
Gain
knob while watching the Signal Meter, you can set your level
appropriately and avoid clipping.
Recording For Long Periods
The maximum size of any .wav file is about 4GB. Depending on the recording rate, this could mean
anywhere from 2 to 13 hours. The
WAV Recorder
can continue recording beyond this limit by splitting
ultra-long recording sessions into a series of files. Once a file becomes about 4GB large, the
WAV
Recorder
will close the file and keep recording into a new file. In this way, you can fill your entire card
with recordings if you leave the module recording without interruption. The
Wav Recorder
can even
record for days or weeks (depending on the size of you card and the sample rate you select in System
Mode). The included card is 16GB and will record for about 27 hours before stopping at the default
recording rate (44.1kHz, 16-bit, stereo).
We highly recommend using a faster card for any long recording (see Recording Rates section).
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Clip
dim
bright

System Mode
You can change the recording sample rate, bit depth, and number of channels in
System Mode.
To enter System Mode, first make sure that the switch is flipped up to
Record
, and
that the
WAV Recorder
isn’t recording or paused. Then, hold the button down for
5 seconds. As you wait, the lights will show you the free space available (see
Checking for Free Space
); keep holding the button down. After about 5 seconds, the button will turn
blue and you can release it. You are now in System Mode.
The left column of lights indicates which parameter you are editing, and the right column indicates the
value of that parameter.
To select the parameter you wish to edit, tap the button. The light on the left column will cycle through
the three options.
To change the value of the parameter you’ve selected on the left side, turn the
Gain
knob. The LEDs in
the right column will change when you turn fully to the left (0%), fully to the right (100%) and/or to the
center (50%). The lights on the right column will tell you the value of the parameter you selected as
follows:
A red light in the left column indicates the Sample Frequency menu; its options, listed in the right
column, are 96kHz (red), 48kHz (white), or 44.1kHz (blue).
A white light in the right column indicates the Bits menu; its options, listed in the right column, are
24 bits (white) or 16 bits (blue).
A blue light in the left column indicates the Channels menu; its options, listed in the right column are:
stereo (red and blue), mono (white).
Note: The System Mode feature only changes what happens when you record, not when you play.
Playback always happens at the file’s native sample rate and bit depth.
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Clip
Sample Freq.
96kHz
48kHz
44.1kHz
Clip
24 bits
16 bits
Bits
Hold 5 sec
Playback
Record
Tap to select
parameter
Turn to set value
Clip
Channels
Mono
Stereo

Recording Rates and Selecting microSD Cards
The microSD card included with the
WAV Recorder
is a Class 10 card and is sufficient for recording at
many high-fidelity rates. With the included Class 10 card, we recommend 44.1kHz/16-bit/stereo,
48kHz/24-bit/mono, or 96kHz/16-bit/mono. The default factory setting is 44.1kHz/16-bit/stereo.
To achieve faster rates such as 96kHz/24bit, or 48kHz/24bit/stereo, a high-speed UHS Speed Class 3
(U3) card is required. Specifically, our tests found one card to be of sufficient speed to record at the
fastest rates of the WAV Recorder:
•
Samsung MicroSDXC EVO Plus (64GB) MB-MC64GA
We found another card which performed well, but had a very occasional glitch at 96kHz/24bit/stereo:
•
SanDisk Extreme PLUS microSDHC (32GB) SDSQXBG-032G-GN6MA
At time of printing, the cost of either of these cards is typically around $20-$30, and they’re available
on Amazon or any number of electronics retailers. Beware of cheap look-alikes, and only purchase
from a reputable seller. Avoid cards with a price under USD 20, they are likely to be fakes.
The following table reports our findings:
*At 44.1kHz/24bit/Stereo on the included Class 10 card, a 1 hour recording has a 4% chance of
dropping samples. Using a faster card is recommended.
**At 48kHz/24bit/Stereo or 96kHz/24bit/Mono on the included Class 10 card, a 1 hour recording
has a 25% chance of dropping samples. Using a faster card is recommended.
While dropping samples is typically not acceptable, we allow the
WAV Recorder
to attempt to record
beyond the limits of the card you choose for several reasons:
•
Short samples have almost no chance of containing glitches. Thus, capturing percussive or brief
samples at high rates is OK, even with slower cards.
Freq.
Bits
Stereo/Mono Included card
(Class 10)
Recommended card
(Samsung EVO Plus)
44.1kHz
16 bit
Mono
√
√
Stereo
√
√
24 bit
Mono
√
√
Stereo
√
*
√
48kHz
16 bit
Mono
√
√
Stereo
√
√
24 bit
Mono
√
√
Stereo
√
/X**
√
96kHz
16 bit
Mono
√
√
Stereo
X
√
24 bit
Mono
√
/X**
√
Stereo
X
√
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•
For some field recordings and other purposes where the recording will be heavily edited, dropped
samples may be acceptable.
•
When recording repetitive sounds where it’s easy to record a sound multiple times in one take,
having one bad section may not be a problem.
If none of these circumstances apply, use a faster card, record at a slower rate, or record in mono.
For most audio recording purposes, 44.1kHz or 48kHz is excellent quality. If the recording level is
sufficiently high, a bit depth of 16-bits will be of high fidelity. If you only require mono samples, we
recommend changing to mono recording mode, and you will be able to record at a higher rate if you
wish.
Dropped Sample Log
The
WAV Recorder
will allow you to record at any sample rate using any card, but if you surpass the
limits of your card, there is a chance the recording will have some dropped samples. The longer the
recording time, the greater the chance this will happen. You may find that making short recordings
(under a few minutes) works perfectly for you at any rate. However, you run the risk of dropping
samples in the recording or creating an artifact in the playback of the .wav file. Depending on your
purposes, this might be unacceptable. The solution is to use a faster card (see list of recommended
cards above).
If any samples are dropped during recording, the
WAV Recorder
will create a text file and log the exact
time position of the dropped samples. The name of the log file will be the same as the name of the
recording, with “.txt” on the end. If you find such a file on your microSD card, open it up and read the
time position of the glitches. Play the .wav file at those times to determine if the glitch needs to be
cleaned up, or if it isn’t a problem. This is just a band-aid (in case you accidentally record at a higher
rate than your card can allow, and there’s no chance of a re-take). To avoid the possibility of dropped
samples when recording at any rate, either use a fast microSD card or keep your settings at a lower
rate.
Checking the Firmware Version
When you power on the module, the LED Signal Meter will briefly show the firmware version number.
The button will be magenta (pink) while the version is being shown.
The left column of lights indicates the major version number (e.g 1.x, 2.x, etc..). The right column
indicates the minor version number (e.g. 1.0, 1.1, 1.2, etc..). The bottom light represents “1”, and the
top light represents “4”. A “0” is represented by no lights on that side.
For version 1.0 (this version), the bottom left blue light will be on, and the other seven lights will be off.
Updating Firmware (Audio Bootloader)
You can update the firmware by playing an special audio file into the
Record
jack. When new firmware
versions are released, the firmware audio files can be downloaded at http://4mscompany.com/
wavrec.php. Check/Follow/Like the 4ms Twitter, Facebook, or Instagram social media feeds to be
notified of firmware upgrade availability, or email us via our website.
1. Unplug all cables and power off the module.
2. Connect a computer or smart phone audio output to the
Left
IN
jack. Remove your phone case, it
may be preventing the cable from fully plugging in.
3. Connect the
Left
OUT
jack to an amp/speakers so you can listen. Turn the amp/speaker volume
down — this is going to be LOUD!
4.
Set the computer/phone's volume to 100%
and the audio player software to 100% volume. Turn
off all audio and vibrate notifications. Close any applications that make notification sounds.
5. Hold down the button while powering up the
WAV Recorder
. The button should start flashing
green. Release the button.
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6. Begin playing the file. Immediately you should see the button flash white, and the other lights flash
a lot. You should be hearing the sounds very loudly out the
Left
OUT
jack.
7. If the sound stops before the file is done playing, there was an error. The button will flash red.
a. Stop the file and rewind to the beginning.
b. Check all cables are plugged in tightly.
c. Tap the button. It should turn green again.
d. Play the file again from the beginning.
8. If the file loads successfully, the
WAV Recorder
will display a chase sequence on the LEDs and the
button will alternate green and blue. Press the button to start using the new firmware.
Tip: some audio interfaces play a pop when they first start playing a file. If this happens, the button
light will turn red as soon as you start playing. One way to overcome this is to hit the button light
immediately after pressing play on the computer, but before the noise starts playing (there’s a 2
second lead time of silence). Or, an easier way to get around this is to use a different device (smart
phones seem to work better than computers for the purpose of updating our firmware).
Tip: Do not play from software like Ableton. We have seen that some software will alter the playback,
which is not desirable here. Play from simple, basic software such as VLC, QuickTime, Windows
Media Player, or Chrome. Turn off any EQ or “Bass Boost” settings.
The open-source licensed source files (in C, for compiling with gcc-arm) can be found at https://
github.com/4ms/ (note: as of printing of this manual, this is not yet posted).
microSD Card
We include a Class 10 card with the
WAV Recorder
, which is sufficient for recording at 44.1kHz. If you
need to record at a higher rate, use a faster card. See
Recording Rates
section for recommended
cards.
Never remove the microSD card while the
Busy
light is on!
It’s OK to remove it if the
Busy
light is off. After inserting a card while the module is powered up, flip to
Record
mode and hold the button down for 2 seconds
to refresh the card. This will mount the card and
display the available free space on the card.
How to format a new microSD Card
Format new cards as ExFAT (preferred) or FAT32
(acceptable). See screenshot (right) for how to set
MacOS standard “Disk Utility” program.
We recommend formatting a cards from time to time
to defragment. A freshly formatted card will perform
better than a card that had its files deleted.
Formatting de-fragments a card, while dragging files
to the trash can does not.
Future Integration with 4ms Listen modules
There’s a header on the back to connect to the
4ms Listen
headphone/line mixer modules. This will
allow you to record directly off the output mixer without any patch cables. See the
Listen
user
manuals.
*Note: at time of printing, the Listen modules are not yet released. See the Listen manuals for
connection details when those modules are released.
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Electrical and Mechanical Specifications
• 6HP Eurorack format module
• 0.98” (25mm) maximum depth
• 10-pin Eurorack power header
• Power consumption (maximums):
• +12V @ 112mA
• -12V @ 12mA
• +5V rail not used
• Audio
OUT
jacks
•
Frequency Response:
•
File:Out = +/-0.1dB max deviation at 20Hz - 20kHz
•
21V peak-to-peak = full scale
•
Up to +20dB digital gain can be applied while playing using Gain knob
• Audio
IN
jacks
•
Signal-to-Noise Ratio (SNR)
•
Measurements taken from recordings made in a typical Eurorack case, powered by a 4ms Row
Power 40 module:
•
-91.7dB @ 16-bit, 44.1kHz
•
-88.9dB @ 24-bit, 96kHz
•
Frequency Response:
•
Out:In = max +/-0.1dB from 20Hz to 15kHz. -0.5dB at 20kHz
•
20V peak-to-peak maximum before clipping
•
Up to +20dB digital gain can be applied while recording or monitoring using
Gain
knob
•
Record
jack
•
Incoming trigger starts/stops recording, or starts/re-starts playback
•
Trigger voltage must be > 1.6V, rising edge is detected
•
microSD card slot accessible from front panel
•
Class 10 card included (16GB)
Jumpers
The PCB has one jumper labeled “JUMP”, which fits on a 2-pin header
located at the bottom right of the PCB.
The jumper must be installed to enable the normalization of the
Left IN
jack to
the
Right IN
jack. If this jumper is missing, patching a signal into the
Left IN
with nothing plugged into the
Right IN
jack will record silence on the right
channel.
The jumper should only be removed if you are connecting the
WAV Recorder
to a 4ms Company Listen module. See the Listen manual for connection
details.
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