Summing Mixer Setup – Documentation – Additional Options – Components
see diagrams and descriptions – select additional features – components
if you have any questions don’t hesitate to contact me
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YOUTUBE CHANNEL
Table of contents
- Connection standards
- Input number and type
- Output number and type
- Output ON/OFF - Mute control
- Output Select - A or B Switch
- Master mono switch
- Master Phase switch
- Built In Monitor Controller
- Direct Monitoring switch
- Direct Monitoring switch + Bypass sum
- Expansion AUX stereo Input
- 21 step Precision gain control
- Vari Gain Switch -10/-15/-20/-25
- Master Active/Passive 2in1 Switch
- Master Active/Passive 2in1 Relay
- Master Insert Send Return
- Multiple Master Insert Send Return
- Auto TRS Master Insert Send Return
- Mono input conversion switch
- Channel Insert Send Return
- MultiBus Sub Group with fixed inputs
- MultiBus Sub Group Matrix routing
- Knob style & colour
- Block Diagram Basic
- External Power Supply
- Passive Summing Gain Reduction
Summing Mixer – Standard Connections
Connector Type – Studio Standards – TRS – XLR – DSUB DB25 Tascam Analog Balanced
READ MOREBalanced XLR / TRS / DSUB are the same from side of the signal conduction. All three types conducts 3 ( three) signals.
D-Sub DB25 Tascam Standard Analog Balanced
TRS 1/4″ balanced : Tip=hot (+), Ring=cold(-) Sleeve=GND
XLR balanced: 1=GND, 2=hot (+), 3=cold (-)
Be sure you’re using Analog DB-25 – NOT (AES/EBU digital)!
AES/EBU pinout scheme follows the analog one closely.
The original AES/EBU pinout was indeed based on the analog pinout, but using the first four balanced lines for AES/EBU in, and the last four balanced lines for AES/EBU out.
Always use Compatible cable with standard Analogue Tascam
Input channels
Channel Count and Connection type (select)
READ MORE1U Rack:
- DSUB: up to 40-48 ch input
- TRS: up to 32 ch input
- XLR: 8 ch input
2U Rack:
- DSUB: up to 96 ch input
- TRS: up to 64 ch input
- XLR: up to 16 ch input
3U Rack: temporary out of stock
- DSUB: up to 128 ch input
- TRS: up to 96 ch input
- XLR: up to 32 ch input
*free to choose mixed mode (d-sub+trs+xrl)
Output channels
Channel Count and Connetor Type (select)
READ MORE- 2 x Stereo out as Main Rec / Monitor
- listen actual volume level print while monitoring
1U Rack:
- DSUB: up to 16 ch out (8 stereo)
- TRS: up to 8 ch out (4 stereo)
- XLR: up to 6 ch out (3 stereo)
- * in case of 16ch input by D-Sub input
2U Rack:
- order (there is no theoretical limitation)
3U Rack: (temporary out of stock)
- order (there is no theoretical limitation)
- limited availability 2020
*free to choose mixed mode (d-sub+trs+xrl)
Master Active – Passive Power ON Activated – Relay
Active mode: POWER ON
Passive mode: POWER OFF
READ MORE- Passive = External Preamp – Your DAW MIC PRE
- Active 1 = Internal Transformer Amp (Neumann/Filtek/Lawo)
- Active 2 = use Both Internal Transformer Amp + External preamp – Your DAW MIC PRE
Benefits: Different amp = Different sound COLOR / Character
Example:
Passive = UAD Apollo Preamps (your preamp)
Active 1 = Neumann Internal Transformer Amp
Active 2 = Neumann + UAD Apollo Preamps
this function enables to connect different kind of mic preamp instead of internal amp
freely can use a completely different sounding amplifier for gain makeup
Active mode: POWER ON
Passive mode: POWER OFF
Master Active – Passive – switch
It gives a DUAL OPERATION (function) for your mixer – you can select between diverse transformer amps, giving a large playground for DIFFERENT SOUND COLOR CHARACTER of your mixes – see Youtube video…
READ MOREWhat’s the 2 in 1 (two in one) Active Passive switch?
- Passive = External Preamps
- Active 1 = Internal Transformer Amp (Neumann/Filtek/Lawo)
- Active 2 = use Both Internal Transformer Amp + External preamps
Benefits: Different amp = Different sound COLOR / Character
Example:
Passive = UAD Apollo Preamps (your preamp)
Active 1 = Neumann Internal Transformer Amp
Active 2 = Neumann + UAD Apollo Preamps
this function enables to connect different kind of mic preamp instead of internal amp
freely can use a completely different sounding amplifier for gain makeup
There are two ways to control by A/P switch:
Passive mode: gain makeup by Your external micpres or DAW amplifiers
Active mode: gain makeup by inside amp Neumann/Filtek/Lawo/NE2OX
Active mode extended : Internal Transformer Amp + (your) External preamps
Active mode: both switches Up
1st switch: signal to Inside amp (passive mode disabled)
2nd switch: Inside amp signal to master out (passive excluded from signal chain)
Passive mode: both switches Down
1st switch: signal to 2nd (bypass Internal amp)
2nd switch: signal to master out (Inside amp excluded from signal chain)
use your DAW inputs or mic pres for the gain, that way you have flexibility over the character.
FAQ – Why two switches instead of one?
Discrete dual balanced signal require 2 x 12 = 24 point solid state dual stereo balanced switching network
Dual switch: keeps it clean and isolated the dual balanced stereo signal flow from input to output
Horizontal Switch placement – YouTube video
Vertical Switch placement – YouTube video
Input Channel (L/R) – convert to Mono – switch
Hard Pan L/R input to CENTER SWITCH – for monos like Kick Bass Snare Vocal…
Mono switch = extra stable real analog mono base for your mix (eg. kick and bass) – then a superior separation, 3D depth for stereo instruments – like on large-format analog recording consoles
READ MOREBenefits:
- Save precious analog channels
- True Analog Mono – center placed in the stereo pan field
- 1 Mono = 1CH – instead to waste stereo – 2 analog L/R for a mono like Kick
1 x Switch or 2 x Switch
Benefits:
- Mono switch = save analog channels from DAW
- Sending from DAW to SUMMING 2 mono instruments (2 channels), instead of 2 x stereo (4 ch’s)
- Mono switch makes center placed real analog mono like on big analog consoles, true analog mono.
You can choose switch type:
1 x Switch per channel
By this feature you can convert “SEPARATELY” choosing L or R input (Hard Panned Left / OR / Hard Panned Right) input signals to become center placed – or leave hard panned L / or / R (see benefits and example below in blue)
1 x switch per 2 channel (channel pair L/R or 1/2)
This feature converts L/R inputs “COMBINED” (two hard panned L/R Input) signals to absolute center placed Mono signal. (1 x Stereo to 2 Mono)
- (mono) SNARE on channel 1Left,
- (mono) KICK on channel 2Right
Customer question: if the panel is not too “crowded” I’d go for 1 sw per channel otherwise 1 sw per 2 channel is fine. They have the same functionality?
Answer: Almost similar. By the 1 sw per channel you can use the “hard pan” feature.
Lets see a 4 input channel setup, each input tracks are mono instruments.
Example 1
1L Input = KICK = Switch (UP) = CENTER
2R Input = Right Overhead = Switch (DOWN) = HARD PAN RIGHT
3L Input = Left Overhead = Switch (DOWN) = HARD PAN LEFT
4R Input = BASS = Switch (UP) = CENTER
Example 2
1L Input = Shaker = Switch (DOWN) = HARD PAN LEFT
2R Input = Vocal or Bass = Switch (UP) = CENTER
3L Input = Snare or Kick = Switch (UP) = CENTER
4R Input = Tambourine = Switch (DOWN) = HARD PAN RIGHT
However, for mono signals (such as kick, snares, lead vocals or bass that should appear in the middle of a mix), it would be a waste to use Stereo L/R panned channels what would amount to two (2) required converters for a mono result.
Routing from DAW to Sum
- DAW Mono Snare: —-Left side of stereo out— (interface Ch 1 Left out)—- sum Left 1IN
- DAW Mono Kick:—-Right side of stereo out (interface Ch 2 Right out)—–sum Right 2IN
- Then switch to mono mode to place Snare and Kick in the center of panorama.
Please note!
1-2 or 7-8 and then engage the MONO buttons to bring those channels to the center of the mix. Mono sounds more powerful
assigned on the VM Summing than using mono in your DAW.
and you save precious stereo CH’s for mono instruments.
With mono signals one should switch these to mono mode to combine them to single D/A converter, thereby avoiding the waste of having to use a D/A pair for one mono track.
Master Insert Send Return Switch
Allows to SEND master stereo L/R signal to external processors like EQ, Comp, Limiter, then RETURN to master out (print / record)
READ MORE- allows to switch between processed or unprocessed signals (comparison purposes)
- Master SND/RET placed before master out
- 100% of the signal routed to SEND
- 1st switch: enable Send to external (route master to SND)
- 2nd switch: enable Return from external (route return to master out)
Active mode: both switch UP (ACTIVE)
- 1st switch: signal to External (enable send out)
- 2nd switch: Return signal to master out (enable return)
Bypass mode: both switch Down (Bypass)
- 1st switch: signal to 2nd switch (bypass send)
- 2nd switch: signal to master out (bypass return)
the 100% of master signal forwarded to send out
Available by TRS DSUB XLR balanced
FAQ – Why two switches instead of one?
- Discrete dual balanced signal require 2 x 12 = 24 point solid state dual stereo balanced switching network
- Dual switch: keeps it clean and isolated the dual balanced stereo signal flow from input to output
Multi Master Insert Send Return chain
Multiple SEND/RETURN = Free Select – exclude or include – INSERT or BYPASS (any one) whichever external gear in the chain see youtube…
READ MORE- CHAINED Connection Eq + Compressor + Limiter or Mic Preamp
- Dedicated Send Return connection and control before master out
Passive summing 2 x Insert example:
- SND A/RET A: Mic Pre 1
- SND B/RET B: Compressor
Active summing 4 x Insert example:
- SND A/RET A: Equalizer
- SND B/RET B: Compressor
- SND C/RET C: Limiter
- SND D/RET D: Reverb
the 100% of master signal forwarded to send out
with BYPASS option can compare differences (eg. with compressor and without compressor)
Available by TRS DSUB XLR balanced
FAQ – Why two switches instead of one?
- Discrete dual balanced signal require 2 x 12 = 24 point solid state dual stereo balanced switching network
- Dual switch: keeps it clean and isolated the dual balanced stereo signal flow from input to output
Auto TRS – Master Insert – Send – Return
Automatically switching audio channels to SEND out when the jack plug is inserted.
- TRS JACK PLUGGED IN = SEND ACTIVE
- TRS JACK UNPLUGGED = NO SEND = Signal next to Master outputs
- The INTERNAL AUTO INSERT SEND BYPASS switch is active ONLY AFTER you actually insert a plug into the SEND TRS socket!
- The signal was non interrupted if nothing connected to SEND
- When the plug is inserted, internal switch activating insertion-detection
- AUTO TRS SWITCH – internally switched balanced routing network
- The signal was non interrupted if nothing connected to SEND
As soon as you conneany audio signal to the SEND OUTPUTS the main signal (before master outputs) gets interrupted, is then processed through an external device and is brought back to the summing mixer via the RETURN INPUTS – whether it is an INSERT or a SEND FX. The amount of SEND FX signal (like the amount of a reverb) then depends on the DRY/WET signal of the SEND FX device)
Master Out – ON/OFF – (MUTE) – switches
- Master Out A (on/off)
- Master Out B (on/off)
- Master Out C (on/off)
Out – A or B – (SELECT) – switch
Select exclusively A/B output
Master Stereo to Mono switch
Mix – Mono Compatibility Test switch
READ MOREplaced before master outputs
The word ‘Mono’ is panned absolutely center. This means both Left and Right speakers reproduce the same word ‘Mono’ at the same volume. This also sounds ‘mono’ and so panned to the middle.
Checking your mix for Mono compatibility as you go is a good preventative measure.
Sometimes just because a mix sounds good in stereo doesn’t mean it will sound good when the left and right channels are combined into a mono signal. In some cases, you may hear what is known as comb-filtering, which will color the sound of your mix and cause peaks and dips in its frequency response. In some cases, instruments may lose their integrity or even seem to completely disappear from the mix!
Phase Invert switch
Phase Invert R side of the stereo signal
READ MOREPhase Invert R + Master Mono mode
*they perform a test-type function (since you only use this function periodically) and because of passive attenuator nature recommended to use at 75 -100% attenuator volume (or max the volume)
*the efficiency of the phase decreases proportionally as the volume decreases
Built In - Inside - Integrated Monitor Control - controller
Direct Monitoring – Inut to Output – Monitor Through Summing Mixer Switch (1xSwitch)
Input 1/2 route to master out / rest summing inputs remains active (mute them from DAW)
READ MOREYou can freely select input 1/2 or 7/8 or 24/25 and so on…
You don’t have to unplug In “everyday” work DAW out 1/2 (or monitor out) routed directly to the summing mixer (pre production, programming, editing etc) just switch to OUT/DIR mode and you have the staright Input to Output routing.
- DOWN POSITION = REGULAR SUMMING INPUT
- UPPER POSITION = STRIGHT TO OUT (NO REDUCTION)
- *rest summing input remains active
For Bypass Mute exclude rest summing inputs see Direct Monitoring switch + Bypass SUM (Total Bypass)
Important!
- Power off internal amp to avoid speaker damage!
- Set Summing to Passive mode (if active)
- Active mode (first time) operate with low level DAW signals!
You can configure DAW monitor outputs for: Instrument output / or / Main Mix monitor outputs /see your DAW Mixer routing settings
No Mix (DIR / OUT) switch – route desired stereo L/R input straight to *Output
Please note: the other summing inputs are still active – you need to mute them from DAW mixer.
Direct Monitoring Switch + Bypass Summing Switch (2xSwithes)
Input 1/2 route to master out + Bypass – Mute rest summing inputs (input can be selected freely)
READ MOREYou don’t have to unplug In “everyday pre production, programming, editing etc” work DAW out 1/2 (or monitor out) routed directly to the summing mixer, simply just switch to OUT/DIR + Bypass mode and you have the staright Input to Output routing
- DIR+OUT/BYP DOWN POSITION = REGULAR SUMMING INPUT
- DIR+OUT/BYP UPPER POSITION = STRIGHT TO OUT (NO REDUCTION)
- *rest summing inputs BYPASSED – MUTED
- Switch 1. Route desired stereo input to Master out
- Switch 2. Mute/Bypass Exclude the other summing inputs
- You can freely select input 1/2 or 7/8 or 14/15 and so on…
Important note!
- Power off internal amp to avoid speaker damage!
- Set Summing to Passive mode
- Active mode (first time) operate with low level DAW signals!
Expansion AUX input
Linking another (second slave) Passive or Active summing unit or Line Input
READ MORESignal process by active summing transformers. (if available) expand up to 100 inputs
This is another stereo input based on electronically balanced XLR – TRS or D-SUB connectors.
- The Expansion Input is an additional stereo input which is routed to current summing network without gain reduction.
- Typically this stereo input would provide for linking with another Summing unit or signal process by active summing transformers.
Channel Insert Send Return
Stereo Input channel insert send return
READ MOREMono conversion by Mono switch performs after return
- Bypass switch OFF (switch down): Input—> Sum Bus—> Master out (regular summing operation)
- Bypass switch ON (switch up): Input—> Send—> E
xternal Process—> Return—> Sum Bus—> Master out - Stereo to Mono signal conversion performs after stereo signal returns to Sum network
Sending 2 x Mono instruments on a stereo L/R channel:
Panning for instruments in the DAW sequencer (cubase, protools etc.) should place the snare hard left, the kick hard on the right.
Send to external:
- Input 1L (snare)—Send—Compressor Left in
- Input 2R (kick)—Send—Compressor Right in
Return from external:
- Compressor Left out —Return 1L (snare)
- Compressor Left out —Return 2R (kick)
Convert hard Left/Right instruments to Mono by STM switch
- switch Stereo to Mono for mono conversion snare/kick
STM (stereo to mono input conversion switch) read more about
Multibus Group Send with fixed inputs
Sub Group summing for Multi–Bus Compression technique
READ MOREFixed sub mixers (slave sum ABCD) with dedicated inputs, each sub mixer (slave sum) group come with individual send/return for external process – then return to Master for final summing.
for example:
- 4 x “slave” sum (A B C D)
- 4 x Send /return
- 1 x Master sum
*you can order as many channels and options you want
Multi-bus compression routing Matrix
ABCD BUS matrix swtich for MULTI BUSS compression / external routing process.
READ MORESee ABCD multi–bus compression routing diagram
STEREO TO MONO conversion switch available only after RETURN / before /signal enter to master summing network
*Mono CHANNEL conversion available on fixed group multibus only
Separate instruments into different categories that will allow freedom of movement. (source MICHAEL BRAUER PRODUCTIONS)
- A – Instruments that are in the upper midrange of a song, such as vocals or keyboards, synths, percussion. Bring up the vocal a lot and it will only effect the instruments assigned to A Choose instruments for a buss that will compliment each other.
- B – Instruments that anchor the song such as drums, bass, maybe cello, congas. Adding more bass or kick will only have an effect on the other instruments assigned to B. Choose instruments that will compliment each other.
- C – Instruments that create transient midrange power and will have a lot of rides, such as guitars.
- D – Instruments that need the warmth of tube and are not played staccato. To be used in combination with other categories for glue factor.
The process is up to an individual’s taste and of course the application which dictates the approach towards the sound you are looking for. Sometimes only send the drums to B and the samples that support it to B and stereo buss, sometimes I don’t. What’s important is that you try every combination and see which sounds the best. Eventually, you’ll know the sound of the different combinations in your head at which point it becomes instinctual read more about : https://www.mbrauer.com/q-a
See more:
Gold Plated – Precision gain control
21 step precision resistor based internal amp gain control potentiometer
READ MORE- Number of steps: 21
- Gold-plated signal path
- Extremely short signal path
- Channel matching: +/-0.1 dB
- Polished “S” shape wiper and contact pins
FAQ: why 2 pots?
- Simply because Neumann is a dual stereo amp (2xStereo amplifiers)
- Neumann 2C/2B electronic circuit requires 2 x stereo potentiometers /side
- Neumann 2B and 2C is a DUAL STEREO summing amp, 1st one for Left, 2nd one for R side.
- Easy to set equally the both L/R side gains by 2 x 21 step precision potentiometers
Variable Headroom Gain Switch
It provides a wide range of gain and volume settings for various applications and gain stages
READ MOREPlaced after passive SUM BUS (passive mixer) determines main out (total) gain reduction – for different (pre amps) applications – gain stage – volume range.
You have a great opportunity to experiment with different gain reductions and determine what sounds better for your mix.
- whether it’s with fewer input signals and more amplification
- or the other way around, with more signals and less amplification
Benefits: you can overdrive by different gains the summing inputs to get more stauration / harmonics
2 position switch values:
- -6dB/-16dB
- -10dB/-20dB
- -15dB/-25dB
- -20dB/-30dB
- -25dB/-35dB
Knob Style and Color (please select)
READ MORESolid aluminium regular round black knob
Vintage style White cream “chicken head” knob
Vintage style Black “chicken head” knob
Vintage style Silver “chicken head” knob
Vintage style Bronze “chicken head” knob
External Power Supply
*out of Europe you need a cheap EU to US/UK/AU ac travel plug adaptor
Neumann, Lawo and Filtek transformer summing amps are equipped with INTERNAL huge voltage regulator stabilizer circuit.
The provided small Switching PSU it provide a stable 18 – 24VDC alimentation, therefore you dont need to use another one.
Please dont change the original PSU!
PSU: 110-240VAC to 18-24 VDC 0,6-1,5A (world wide) EU plug
*out of Europe you need a cheap EU to US/UK/AU plug travel power adaptor
Passive Summing Gain Reduction
Maintaining the passive summing box within the working range of your DAW interface is essential because it ensures optimal sound quality SNR and adequate headroom.

