Heritage Audio MCM-32 User manual

USER MANUAL
32-CHANNEL
SUMMING MIXER
MCM-32
September/2022+Rev.+

2
INTRODUCTION
CONTENTS
DESCRIPTION
GETTING STARTED
APPLICATIONS
WIRING FOR DB25 CONNECTORS!
SPECIFICATIONS!
SIGNAL FLOW!
TROUBLE SHOOTING
WARRANTY STATEMENT
REGISTRATION!
RECALL SHEETS
2
2
3
4
6
10
12
13
14
15
15
16
INTRODUCTION
TABLE OF CONTENTS
Thank you for choosing the MCM-32 Summing Mixer. Heritage Audio is dedicated to bringing you ´the sound of
yesterday for tomorrow´. We specialize in capturing that unique, enticing sound that everybody has fallen in love with.
For years engineers, producers and musicians have been yearning for that classic vibe. Usually the only option is to
search for old, used original equipment that is almost always in a questionable state of operation. This brings with it a
whole lot of other issues, making the experience less than desirable. Not to mention the very high prices asked for this
equipment, which makes them virtually unobtainable for the great majority. Now it´s possible to obtain that same sound
with a brand new piece that will give you all the problem-free, heavy-duty use you´ll need for years of music making
history.
Peter Rodriguez
CEO!
Heritage Audio - Madrid, Spain
© 2022 Heritage Audio S.L. is the sole owner of the copyright of all information and drawings contained in this manual which are not to be copied or
reproduced by any means or disclosed in part or whole to any third party without written permission.
Heritage Audio reserves the right to alter specifications without notice. The information in this manual has been carefully checked and is believed to
be accurate at the time of publication. However, no responsibility is taken by us for inaccuracies, errors or omissions nor any liability assumed for any
loss or damage resulting either directly or indirectly from use of the information contained within it.
MCM-32
AC POWER CORD EU & US
POWER SUPPLY HA-PSU02

DESCRIPTION
The MCM-32 from Heritage Audio takes mountable analog summing mixers to a whole new level. By combining vintage
quality sound with sophisticated routing options, they are the perfect partner for popular hybrid setups by integrating
analog gear with your DAW. The routing options are simply incredible as there are enough inputs and outputs for every
imaginable scenario. Now you can finally connect all of your equipment to one central piece for the ultimate control.
The smart summing topology employed in the MCM series of mixers allows for an impressive headroom and surprisingly
low noise figure for a 32 channel, vintage topology mixer. Special care has been taken on improving crosstalk and self-
noise figures from those of vintage designs in order to accommodate the new MCM mixers into the digital era.
Much has been written on the pros and cons between active (current) and passive (voltage) summing topologies. Some
may claim one is better than the other but the truth is active summing is less susceptible to noise and voltage, passive
summing has a nice, vintage sound associated with its gain makeup circuit.
The smart hybrid summing topology used in the MCM-32, where the channels are current-summed ( active ) into their
corresponding subgroups and the subgroups voltage summed ( passive ) into the master section, has proven to give
massive headroom and lower noise without making any compromises to its vintage characteristic sound.
"
The MCM-32 employs a unique configuration, offering 32 input channels arranged into 4 stereo subgroups of 8
channels. Each channel features center detent Pan and Fader concentric controls plus balanced insert and mute
switches.
The insert send points always have the signal present, so they can also be used as direct outputs for recording without
additional patch bays.
Each group has its own stereo fader and balanced insert point and all 4 stereo subgroups are passively summed into
the master bus. The gain is restored by means of a 73-style class A, transformer coupled, mic preamplifier, featuring a
total of 4 of our exclusive Carnhill transformers (an input and an output transformer for each channel of the stereo
master bus), capable of delivering a full +26 dBu output. This master section is also provided with its own balanced
insert point."There is also a stereo MONITOR OUTPUT that mirrors the MIX OUTPUT for extra convenience.
All connections on the back are made by DB-25 connectors following the Tascam protocol, with the exception of the MIX
OUTPUT and the MONITOR OUTPUT connections, which are on dedicated gold plated XLRs.
3

GETTING STARTED
4
FRONT
1
2
3
4
5
PAN
Places the signal within the
stereo spectrum, left, center,
right or any setting in between.
FADER
Attenuates the signal sent to
the Master Bus from unity to
minus infinity. The control has a
stepped feel for easy recall of
settings."All the way clockwise
equals unity gain, while at 12
o’clock means an approximate
20 dB of attenuation. (Or -20
dB of gain).
ON (CHANNEL)
When pressed, the related input
is added to the subgroup bus.
INS (CHANNEL)
Turns the insert on. The insert
send always has the signal
present, while pressing the INS
switch activates the insert
return input.
ON (SUBGROUP)
When pressed, the output of
the subgroup is sent to the
Master Bus.
1
2
3
4
5
6
7
8
9
11
10
6
7
8
9
10
FADER
Attenuates the signal sent to
the Subgroup bus from unity to
minus infinity. All the way
clockwise equals unity gain,
while at 12 o’clock means an
a p p r o x i m a t e 2 0 d B o f
attenuation. (Or -20 dB of gain).
INS (SUBGROUP)
Turns the insert on. The insert
send always has the signal
present, while pressing the INS
switch activates the insert
return input.
VU Meters
Measures the average level at
the Master outputs.
0 VU = +8 dBu.
Reads post fader and post
insert.
ON (MASTER)
When pressed, the output of
the Master is sent to the Output
connectors.
MASTER FADER
Attenuates the Mix’s output
from unity to minus infinity. The
control has a stepped feel for
easy recall of settings. All the
way clockwise equals unity
gain, while at 12 o’clock means
an approximate 20 dB of
attenuation. +
11
12
13
14
5
INS (MASTER)
Turns the insert on. The insert
send always has the signal
present, while pressing the INS
switch activates the insert
return input.
PHANTOM POWER SWITCH
Activates 48V
MIC PAD BUTTON
20dB Reduction Ahead of Input
Transformer
INPUT GAIN SWITCH
5dB Steps From 30 to 80
HI SHELF ± 15dB at 12 kHz
GAIN STRUCTURE
"
The gain structure in the MCM-32 is quite simple and intuitive with no compromises being made on the “secondary” inputs and
outputs, like the insert sends and returns.
Therefore, all connections are balanced and all outputs are nominal +4 dBu and able to drive 600 Ω.
The gain structure is such that with all faders up, any input to any output is unity gain.
+4 dBu at one channel input, fader all the way up, subgroup fader all the way up, gives +4 dBu at the channel and subgroup insert
send points, and at the main send and output as well.
+4 dBu at the channel or subgroup insert returns will give +4 dBu at the main send and output as well.
+4 dBu at the main insert return will give +4 dBu at the main output.

5
All XLRs are:
Pin 1: GND!
Pin 2: Hot!
Pin 3: Cold
1
2
3
3
2
1
GND!
Hot (+)!
Cold (-)
MALE XLR
FEMALE XLR
REAR
1
2
3
4
5
MIX OUTPUT
XLRs for Mix Output L and R.+
MONITOR OUTPUT
XLRs for Monitor Output L and
R.+
MASTER INSERT SEND
XLRs (2) for Master Insert Send
L and R.+
MASTER INSERT RETURN
XLRs (2) for Master Insert
Return L and R.+
INS. SENDS 1-32
DB25 (4) for Insert sends 1-8,
9-16, 17-24, 25-36.+
3
4
1
2
7
8
9
5
10
6
6
7
8
9
10
POWER
5 pin XLR for the external HA-
PSU02 power supply unit.+
SUBGROUP 1-8
INSERT SENDS
DB25 for Subgroup 1-8 Insert
sends.+
SUBGROUP 1-8
INSERT RETURNS
DB25 for Subgroups 1-8 Insert
Returns.
INPUTS 1-32
DB25 (4) for Channel Input 1-8,
9-16, 17-24, 25-36.+
INS. RETURNS 1-32
DB25 (4) for Insert Returns 1-8,
9-16, 17-24, 25-36.+
* All XLR connections are Gold Plated

6
8 CHANNEL
SUMMING
MONITOR
SPEAKERS
THUNDERBOLT
COMPUTER
LINE
OUTPUTS
INPUT 1-8
INPUT 1-2 (L&R)
CHANNEL 1-8
SUBGROUP 1&2
MASTER
APPLICATIONS

7
8 CHANNEL SUMMING
+ INSERTS
MONITOR
SPEAKERS
THUNDERBOLT
COMPUTER
LINE
OUTPUTS
INPUT 1-8 FROM DAW
INPUT 1-2 (L&R)
CHANNEL 1-8
SUBGROUP 1&2
MASTER
INPUT L&R
OUTPUT L&R
MASTER INPUT!
(COMPRESSOR)
MIX OUTPUT TO DAW
CHANNEL 1-8 INSERTS!
(EQUALIZER)
INSERT SEND 1-8 TO EQ
EQ TO INSERT RETURN 1-8

8
32 CHANNEL TO
8 SUBGROUPS
CHANNEL 1-32
SUBGROUP 1-8
MASTER
THUNDERBOLT
COMPUTER
MONITOR L
MONITOR R
AUDIO INTERFACE
I/O 32x32
SUBGROUP 1-8
TO CHANNELS 1-8
MIX OUTPUT (L&R)
TO CHANNELS
9 &10
TRACKS 1-32
TO CHANNELS 1-32
25-32
17-24
9 -16
1- 8

9
32 CHANNEL TO
8 SUBGROUPS + INSERTS
CHANNEL 1-32
SUBGROUP 1-8
MASTER
TRACKS 1-32
TO CHANNELS 1-32
OUTPUT
L&R
INPUT
L&R
STEREO MASTER
L & R!
(COMPRESSOR)
SUBGROUP INSERTS
1-8
(4X STEREO COMPRESSORS)
INSERTS
25-32
25-32
17-24
WORD CLOCK OUT
THUNDERBOLT
PORTS 1 & 2
9 -16
1- 8
AUDIO INTERFACE 1
I/O 32x32
CHANNEL INSERTS 1 - 32
SENDS & RETURNS
AUDIO INTERFACE 2
I/O 32x32
25-32
17-24
9 -16
1- 8
WORD CLOCK IN
CHANNELS 1 - 32
STEREO MASTER
INSERT RETURNS 1-32
INSERT SENDS 1-32
INSERTS EXPLAINED
Channels 1-32 - DAW (Plug-in)
Subgroups 1-8 - Hardware
Stereo Master - Hardware
MONITOR L
MONITOR R

1
INPUT 1
2
INPUT 2
3
INPUT 3
4
INPUT 4
5
INPUT 5
6
INPUT 6
7
INPUT 7
8
INPUT 8
All DB25 multi pin connectors are TASCAM protocol. This same protocol is also used by AVID amongst many others,
and is a follows:
The list of the DB25 connectors used and their corresponding channels are as follows:
TASCAM DSUB
CHANNEL #
CHANNEL I/P
1-8
1
OUTPUT 1
2
OUTPUT 2
3
OUTPUT 3
4
OUTPUT 4
5
OUTPUT 5
6
OUTPUT 6
7
OUTPUT 7
8
OUTPUT 8
It is worth noting that, in order to avoid ground loops, the DB25 ground connections are lifted on the MCM-32 side,
leaving the ground paths of your DB25 snakes only acting as shields and preventing any current returns.
TASCAM DSUB
CHANNEL #
CHANNEL O/P
1-8
Pin-out for TASCAM DB25 8 Channel Balanced Connector
INSERT RETURNS 1-8:
INSERT SENDS 1-8:
H = HOT
C = COLD
G = GROUND
WIRING FOR DB25 CONNECTORS
10
SUBGROUP SEND & RETURNS

11
1
INPUT 9
2
INPUT 10
3
INPUT 11
4
INPUT 12
5
INPUT 13
6
INPUT 14
7
INPUT 15
8
INPUT 16
TASCAM DSUB
CHANNEL #
CHANNEL I/P
9-16
CHANNEL INPUTS 9-16:
1
INPUT 1
2
INPUT 2
3
INPUT 3
4
INPUT 4
5
INPUT 5
6
INPUT 6
7
INPUT 7
8
INPUT 8
TASCAM DSUB
CHANNEL #
CHANNEL I/P
1-8
CHANNEL INPUTS 1-8:
1
INPUT 17
2
INPUT 18
3
INPUT 19
4
INPUT 20
5
INPUT 21
6
INPUT 22
7
INPUT 23
8
INPUT 24
TASCAM DSUB
CHANNEL #
CHANNEL I/P
17-24
CHANNEL INPUTS 17-24:
1
INPUT 25
2
INPUT 26
3
INPUT 27
4
INPUT 28
5
INPUT 29
6
INPUT 30
7
INPUT 31
8
INPUT 32
TASCAM DSUB
CHANNEL #
CHANNEL I/P
25-32
CHANNEL INPUTS 25-32:
CHANNEL INPUTS
1
INS SEND 9
2
INS SEND 10
3
INS SEND 11
4
INS SEND 12
5
INS SEND 13
6
INS SEND 14
7
INS SEND 15
8
INS SEND 16
TASCAM DSUB
CHANNEL #
INSERT SENDS
9-16
INSERT SENDS 9-16:
1
INS SEND 1
2
INS SEND 2
3
INS SEND 3
4
INS SEND 4
5
INS SEND 5
6
INS SEND 6
7
INS SEND 7
8
INS SEND 8
TASCAM DSUB
CHANNEL #
INSERT SENDS
1-8
INSERT SENDS 1-8:
1
INS SEND 17
2
INS SEND 18
3
IINS SEND 19
4
INS SEND 20
5
INS SEND 21
6
INS SEND 22
7
INS SEND 23
8
INS SEND 24
TASCAM DSUB
CHANNEL #
INSERT SENDS
17-24
INSERT SENDS 17-24:
1
INS SEND 25
2
INS SEND 26
3
INS SEND 27
4
INS SEND 28
5
INS SEND 29
6
INS SEND 30
7
INS SEND 31
8
INS SEND 32
TASCAM DSUB
CHANNEL #
INSERT SENDS
25-32
INSERT SENDS 25-32:
INSERT SENDS
1
INS RETURN 9
2
INS RETURN 10
3
INS RETURN 11
4
INS RETURN 12
5
INS RETURN 13
6
INS RETURN 14
7
INS RETURN 15
8
INS RETURN 16
TASCAM DSUB
CHANNEL #
INS RETURNS
9-16
INSERT RETURNS 9-16:
1
INS RETURN 1
2
INS RETURN 2
3
INS RETURN 3
4
INS RETURN 4
5
INS RETURN 5
6
INS RETURN 6
7
INS RETURN 7
8
INS RETURN 8
TASCAM DSUB
CHANNEL #
INS RETURNS
1-8
INSERT RETURNS 1-8:
1
INS RETURN 17
2
INS RETURN 18
3
INS RETURN 19
4
INS RETURN 20
5
INS RETURN 21
6
INS RETURN 22
7
INS RETURN 23
8
INS RETURN 24
TASCAM DSUB
CHANNEL #
INS RETURNS
17-24
INSERT RETURNS 17-24:
1
INS RETURN 25
2
INS RETURN 26
3
INS RETURN 27
4
INS RETURN 28
5
INS RETURN 29
6
INS RETURN 30
7
INS RETURN 31
8
INS RETURN 32
TASCAM DSUB
CHANNEL #
INS RETURNS
25-32
INSERT RETURNS 25-32:
INSERT RETURNS

SPECIFICATIONS
•Channel Input Impedance: Greater than 20 kΩ.
•Maximum channel input level: Greater than"+26 dBu.
•Maximum insert return input level: Greater than"+26 dBu.
•Maximum insert send level: Greater than +27 dBu, able to drive 600 Ω.
•Maximum output level: Greater than +26 dBu into 600 Ω.
•Frequency response: ±0.5 dB 20 Hz to 20 kHz.
•THD + N: Not more than 0.07% from 50 Hz to 10 kHz at +20 dBu output (22 Hz to 22 kHz bandwidth) into 600 Ω.
•Noise: All faders up, all subgroups in, measured at the main output, 22 Hz to 22 kHz. Better than -80 dBu.
12
MCM-32&POWER&SUPPLY&
The MCM range of summing mixers features a hybrid power supply concept, in a very similar way to famous On Slot
Technology (OST) employed in Heritage Audio´s successful 500 series enclosures range.
An external switching power supply enters the unit by means of a 5 pin XLR connector, where it is further filtered using
a PI configuration, using a big common mode choke.
Further, linear regulation stages are used. Different regulation is used for channels and buses, and output stages.

SIGNAL FLOW
13
INPUTS/INSERTS TLA AMP ON FADER PAN
SUBGROUP O/P 1, 3, 5, 7
SUBGROUP O/P 2, 4, 6, 8
1, 9, 17, 25
2, 10, 18, 26
3, 11, 19, 27
4, 12, 20, 28
5, 13, 21, 29
6, 14, 22, 30
7, 15, 23, 31
8, 16, 24, 32
CHANNEL 1-32 SECTION
MASTER SECTION
SUBGROUP O/P 1
SUBGROUP O/P 3
SUBGROUP O/P 5
SUBGROUP O/P 7
SUBGROUP O/P 2
SUBGROUP O/P 4
SUBGROUP O/P 6
SUBGROUP O/P 8
MASTER OUT L
MONITOR OUT L
MASTER OUT R
MONITOR OUT R

TROUBLE SHOOTING
PROBLEMS
SOLUTIONS
My audio signal is not appearing at the Stereo Master.
Have you pushed the white ´ON´ button for that channel?.
Still no audio signal at the Stereo Master.
You need to increase the inner grey knob for more
channel volume.
Yet still no signal arriving at the Stereo Master.+
You might need to increase the volume on the blue
Subgroup knob.
Even still, no signal arriving at the Stereo Master.+
Have you pushed the white ´ON´ button for that
Subgroup?
Even after checking all of that, the signal still isn´t arriving
at the Stereo Master.
Make sure you haven´t pushed an INS (Insert) button
without having anything inserted or the without the
patchbay"being ´normalled´.+
I´m only receiving audio on the ´Left´ side of the Stereo
Master.
Check to see if the outer ring ´PAN´ control has been set
to the extreme left side.""""""+
There is a center detent to assure equal signal to both
sides.+
There is no signal at all appearing at the Stereo Master.+
Double check your cables and connections.
I´d like to get a Direct Out from each channel."Is it
possible?+
Yes, of course."Just tap the INSERT SEND signal, which
is always active."This goes for Channels as well as
Subgroups and Stereo Master.+
I´d like to have a 12 channel bus for my drums."How
could I configure it?+
Just use the first 8 channels, sent to their Subgroup 1&2."
Take the output from Subgroup 1&2 and send it to
channels 9&10."Then at the Subgroup 3&4 you will have
channels 1-8 and channels 11-16."So that would allow
you a drum bus of up to 14 channels.+
14
* For any further doubts or questions please get in contact with us at: [email protected]!

LIMITED 2 YEAR WARRANTY
Heritage Audio MCM-32 Summing Mixer is warranted by Heritage Audio SL to be free from defects in materials and
workmanship for the period of 2 years to the original purchaser. In the event of such defects, the product will be repaired
without charge or, at our option, replaced with a new one if delivered to Heritage Audio prepaid, together with a copy of
the sales slip or other proof of purchase date. The warranty excludes problems due to normal wear, abuse, shipping
damage or failure to use the product in accordance with the specifications.
Heritage Audio shall not be liable for damages based upon inconvenience, loss of use of the product, loss of time,
interrupted operation or commercial loss or any other damages, whether incidental, consequential or otherwise.
This warranty is not transferable.
Heritage Audio and the Heritage Audio “H” logos are registered Trademarks owned and/or licensed by Heritage Audio.
REGISTRATION
15
Please visit our website:
WARRANTY STATEMENT
https://heritageaudio.com/registration/

RECALL SHEETS
16
Session / Title: Track: Connected Equipment: !
Date: Instrument: Notes:
Switch ON
Switch OFF
MASTER
FADER
7-8
L R
FADER
PAN
L R
FADER
PAN
ON
INS
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
5-6
3-4
1-2
FADER
FADER
FADER
FADER
ON
ON
ON
ON
INS
INS
INS
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
Session / Title: Track: Connected Equipment: !
Date: Instrument: Notes:
Switch ON
Switch OFF
MASTER
FADER
7-8
L R
FADER
PAN
L R
FADER
PAN
ON
INS
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
L R
FADER
PAN
5-6
3-4
1-2
FADER
FADER
FADER
FADER
ON
ON
ON
ON
INS
INS
INS
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS
ON
INS

www.heritageaudio.com
HERITAGE AUDIO. C/ Alfonso Gómez, 38, 3C. 28037 Madrid – Spain. Tel: [phone]
[email protected]