DUTCH IM2.3 User manual

DuTCH audio IM2.3 manual (v1.0 24-05-2018)
Thank you for purchasing the DuTCH audio mastering Insert Matrix IM2.3. In this manual I
will explain how this de ice works and how to use it. Because this is not really a beginner’s
de ice, I assume you already know quite some things so I will skip the basics. I will go from
the inputs, to the inserts and finally to the outputs, basically how the de ice handles
signals.
Inputs:
Rearpanel:
The IM2.3 has two balanced inputs which can be ound on the back o the unit. Both inputs
consist o Neutrik XLR’s.
Input switches:
On the rontpanel you can choose between the 2 inputs by pushing the corresponding
switch. It’s also possible to use both inputs at the same time, but keep in mind that this will
cause some impedance changes.
Polarity:
Above the 2 input selector switches you will ind the ‘polarity switch’ which will swap the
polarity o the balanced inputs on both Le t and Right. Sometimes swapping polarity will
give a better impulse response, mostly in the low requencies. In most cases swapping
polarity is not needed, but in the cases where you want to, this button comes in very
handy.
Active gain:
Both inputs are totally passive with just relays, but by pushing the ‘active gain’ switch you
will enable the active gain stage which enables you to change the input gain to your liking.
In the mid position, so at the 12 o’ clock position, there is no gain applied though it passes
the active gain circuit. You can change the gain in 23 x0.5dB steps rom +5.5dB to -5.5dB
with stepped switches.

Inserts:
Rearpanel:
The IM2.3 has 8 inserts connected on the back with industry standard Tascam DB25 analog
connectors. Each connector holds 2 inserts corresponding with the rontpanel numbering.
Be careful with DB25 tascam standard premade cables. The digital AES/EBU cables like the
Hosa AES-803T ha e their XLR’s connected in the wrong way which swaps send/return.
Though it’s an easy fix (swap male and female), you might want to look at this carefully.
Insert 1 and 2:
This is a 100% passive insert section with just relays. When disabled, it will directly pass
the signal internally to the next stage. When you enable the insert (1 and/or 2), it will pass
the signal to the corresponding send/return. It will irst pass insert 1 and then it goes into
insert 2. When you push the ‘swap 1 /2 button, it will swap the order o the inserts. So
instead o 1>2 it will be 2>1.
Insert 3 and 4:
Insert 3 and 4 are the same as insert 1 and 2.
Insert 5 and 6 ( id/side):
Insert 5 and 6 are more special, they can be used or Mid/Side processing.
When set to stereo, it will be 100% passive and it will not pass the active MS circuit at all.
The active MS circuit is based around THAT and BurrBrown chips and is an extended
version o the Wayne Kirkwood circuit.
Mid Side:
When the MS button is engaged, both inserts 5 and 6 will work in MS mode. Le t channel is
Mid (sum), Right channel is Side (di ). When the width switch is disabled, no gain changes
are done on mid or side. But you should keep in mind that the sum (mid) will be louder
then the side channel because o the LR summing/gain buildup. So you should be care ul
with ‘distortion sensitive equipment’ but in practice this will not lead to any problems.
Width:
When you enable the width button, the width circuit becomes active and you can change
the gain o the side channel, making it more wide or narrow. I choose to take it out o the
circuit because o the extra stage needed to take care o the width control and also or
AB’ing. I picked a de ault gain range o +/- 3dB up with 23 steps. In practice you will not

boost or cut the side channel more then 3dB, so I thought it was better to have a more
precise and recallable range, then going or a wide but less precise range.
Mid / Side ute:
The mid and side mute buttons will let you mute mid or side so that you can listen to just
the sum or the di .
Other MS functions:
When you don’t use the insert switches 5 or 6, you can still make use o the mid/side
unctionality. When the stereo/MS switch is set to MS, it passes through the mid/side
circuit. What you can do or instance, is making the side channel a bit more wide or narrow
by changing the gain on the side channel with the width knob. You can also listen to just
the mid or side channel by muting the corresponding channel.
Insert 7 and 8:
Insert 7 and 8 are the same as insert 1 and 2, so 100% passive.
Outputs:
Rearpanel:
On the rearpanel you will ind 2 outputs with balanced Neutrik XLR’s.
Output switches:
On the rontpanel you can choose between the 2 outputs by pushing the corresponding
switch. It’s also possible to use both outputs at the same time, but keep in mind that this
could cause some impedance and so level changes.
Ins Bypass:
When you engage the ‘Ins bypass button’ all inserts will be bypassed at once. You will see
that all lights on the insert switches rom 1/8 will go out, giving you extra visual eedback.
Out 1:
Out 1 is a passive output selector with just relays, so no active circuit. So basically, it’s
passing the signal rom the inserts straight into the output. But when you push the ‘out 1
bypass button’, it will bypass all inserts and the active gain stage ‘out 1 monitor trim’
comes active. The monitor trim will allow you to change the bypass gain to make up or the
processing o the inserts. This way you can A/B between the analog processing and level-
matched bypassed signal. The gain range is set rom -1dB till + 12dB done with a potmeter
instead o a stepped switch or a more precise adjustment. And since this is just an AB
unction no recall is needed. Internally the gain range o the monitor trim can be calibrated
with 2 multiturn trimmers.
Out 2:
Out 2 is a passive output selector with relays and no active stages.
Technical:
Hardware:
This device is built around mostly passive circuits, but some parts need to be active, but
always with transparency in mind. The sturdy rontpanel-switches have, depending on their
unction, 2 color leds or visual eedback. All relays are high sensitive, long-li e (15.000.000
cycles) Omron Relays. Stepped switches are high quality Blore Edwards or long li e and
really nice mechanical eel. In and output connectors are gold plated Neutrik and industrial
DB25 connectors or inserts. Active sections make use o SSM214x and Burr Brown drivers,
Mid/Side section makes use o THAT drivers, known or their clean and transparent sound.

PSU’s consist o long-li e industrial Meanwell SMPS’s which run more quietly and e icient
then linear PSU’s.
When this device is used in passive mode, so input without active gain, no mid/side and no
gain compensation on the output, it’s 100% passive and only relay-contacts are inline. This
means it’s basically a straight wire.
Pushswitch labeling:
To have some extra visual eedback on the push-switches you can put labels under the
switch-covers. You can simply, but care ully, remove the switch cover with a small
screwdriver and put something like a transparent dymo letratag sticker on the white plastic
piece inside the switch-cover.
Specifications:
Some real-world measurement igures done with RMAA on a Lynx Hilo at 24bit 96khz.
When doing the measurements, the inserts where not activated. The inserts themselves
hardly add noise or distortion by itsel because the only di erence is that it will be send to
the DB25 connector instead.
Lynx Hilo @
2496 with
no cables
on inserts
straight
cable
(cable
directly
rom
DA/AD)
passive
ode
(input to
output in
passive
mode)
active
gain on
(active
input on
set to 0)
MS + width
on
(MS enabled
and width
set to 0)
bypass
gain co p
on
(output byp
comp set to
0)
active gain
MS and
width on
(input gain at
0, MS and
width on)
Noise level,
dB (A): -119.3 -119.3 -116.5 -115.8 -115.2 -114.1
Dyna ic
range, dB
(A):
119.3 119.3 116.4 115.8 115.2 114.0
THD, %: 0.0005 0.0005 0.0006 0.0006 0.0006 0.0007
IMD +
Noise, %: 0.0007 0.0007 0.0008 0.0009 0.0010 0.0012
Stereo
crosstalk,
dB:
-116.7 -104.3 -92.9 -61.8 -105.6 -61.6
Input voltage 100 to 240VAC 50/60HZ.
Power consumption minimum 5 watt
Power consumption maximum 30 watt
(Power consumption depends on the amount o inserts, input, output etc activated)
Unit size: standard 2u 19 inch, depth 25cm
Weight: approx 4kg
Speci ications subject to change because always improving
© DuTCH.audio 2018
Handmade in Holland on Solarpower
in [e-mail]
https://dutch.audio
Phone: [phone]