Lawo - transparent summing mixer

Modern analog vibe sound with pleasant analog distortion and nice harmonics  great finisher of your final mix. If you’re looking for something punchy and clean ssl-ish overall blend for your final mixes, the Lawo is the best choice!

16x2 Lawo DV975 (all style) summing

769 € +shipping (basic setup)

Modern Analog Vibe – All style purposes

Basic Version D-Sub In/ TRS Out (for xlr out add 20€ extra)
  • Amp Type: Lawo DV975
  • 16 INPUT DB25 (basic) or TRS 1/4″(order) BALANCED
  • 2×21 Step Precision Lawo DV975 MASTER GAIN POT
  • PSU: 110-240VAC to 18-24 VDC 0,6-1,5A (world wide) EU/UK/US plug
  • Unique Name or Logo engrave design (order)
  • Power Led: Red, Green, Yellow or Blue
For TRS Input add 20 € extra 
For XLR Out add 20 € extra
  • Full balanced dual stereo discrete signal path from input to output!
  • *gallery picture shows 4 x stereo to mono input conversion, the basic unit come by 2xSTM

Customer Reviews

Paul’s Summing Box – the real thing!

My box is summing 32 inputs (16×2), has 2 Stereo-Outs and uses Lawo-Transformers and what can I say: it does exactly what I was looking for. Every little thing, every detail in the mix – instruments, voices, reverb, etc – seems to be placed right where I want it to be. Actually I thought, all the time there has been a curtain between my ears and my Genelecs which has finally raised.

I am very happy with this setup and I want to thank Paul for all his support and the really fine work he has done for me and my studio. Thanks!

read more on gearslutz

Lawo 32 channel summing 

Resolution and stereo image: first thing I’ve noticed was that mix is “glued together”. I have a feeling of working with a tape, like the nasty transients are smoother, thus allowing for a warmer mix. It has a certain “velvety” feel to it. I also have the feeling that haufe transformers generate additional harmonics, that make the impression of excellent equal frequency distribution all over the spectrum. Mix is not dull or over exited, just plain great analog sounding.
Stereo image is unbelivable. A huge step up from MiB (mix in a box). Bass frequencies are well balanced (from bottom mid all over to sub)

Dejan Radievic

read more on gearslutz

Custom designed 4- 96 input channel mixers

4 6 8 10 12 14 16 20 24 32 56 64 96 input channel studio summing mixer

Lawo – Haufe / Pikatron transformer summing amp

  • AMP: Lawo DV975 Dual mutually independent Vintage summing amplifier
  • (dual stereo balanced – up to 100 inputs – based on tech. doc.  Lawo GmbH)
  • Max output gain: + 36dBm
  • Max input gain: + 6dBm
  • Gain adjustment range: +6 – 36dB)
  • Standard level inputs:   Balanced, floating to ground
  • Standard level outputs: Balanced, floating to ground
  • Output impedance (load imp) : >300ohm
  • Crosstalk attenuation: >110db from channel to channel
  • Frequency response: <+0/-0,25dB (20Hz to 20kHz: <+0/-0,5dB
  • Signal/ Noise rate: <-101dBqp (measured with not connected DAW inputs)
  • Extraneous signal level with V=0db : <-99dMrms/-94dBmrms with 1/30 sources
  • Input Transformers:  2xHaufe
  • Output Transformers: 2XPikatron
  • Signal/ Noise rate: -110dB A-weighted
  • Operation voltage: 18,6 – 28V/600- 1500mA

Mixer summing network (passive side)

  • Dual Stereo Discrete Solid State Balanced: 1xStereo Left side/1xStereo Righ side
  • In/Out:Balanced, floating to ground
  • Output impedance 600-1k ohms balanced 
  • Frequency response: 0-500Khz
  • Crosstalk 1Khz: -95dB
  • Signal/ Noise rate: -110dB
  • Pure hand made! Hand wired and tested point-to-point!
  • Selected VISHAY DALE military metal-film resistors
  • D-Sub DB25 Tascam Standard Analog Balanced
  • TRS  1/4″ balanced connection : (Tip:HOT/,Ring:COLD/Sleeve:GROUND)
  • XLR (3 pin xlr) AES industry standard “pin-2 hot” 
PSU – power supply
  •  110 – 240VAC 50-60Hz 18-24VDC 0.8-1.5A  
  • world wide UK/US/EU plug

Complete control from DAW 

If you want to breathe life into your digital tracks, a summing mixer is the best way to do it. Summing mixers add real analoque harmonics and punch to the sound of your productions, letting you easily mix stems output from your DAW in the analog domain.

  • Fully balanced dual stereo solid state network & switching network from input to output.
  • Can be left “free” unconnected inputs 4-8-12 or more inputs! 
  • No unused/unconnected input problem!
  • No thermal noise on passive mode due to custom-developed balanced summing network.
  • Absolutely repeatability DAW control: Volume Panorama, EQ, and effects sends of your mix from within the DAW, and send as many as 4-8-16 different tracks or submixes to Summing Mixer.

Designed for multi-purpose applications:

  • Instrument balanced/unbalanced signal from synths like Moog, Nord, Yamaha etc.
  • handle large external instruments like samplers, tape machines, drummachines etc.
  • fit to all brand of DAW interfaces like Digidesign 192, Avid HD I/O 16X16,Universal Audio, RME Fireface, Prism, Lynx Aurora, Apogee, Motu, Focusrite, Metric Halo, Steinberg MR816, and so on..
  • external signal processors eg. EQ, Compressor, Limiter, Multi Effects Processors like Massenburg, Drawmer S3, Lexicon, Alesis, Tube-Tech LCA2B, JoeMeek, FMR Audio RNC DBX, ART etc.
  • large number of external mic preamps like AMS Neve 1073,Aphex Channel, Great River, Avalon, Chandler Limited, Crane Song, SPL, Focusrite, Presonus, Midas, Summit Audio, ART Pro and so on…
  • Extremely simple, Discrete, pure, and transparent signal path.

Can be used for external DAW summing or as a line summing mixer for effects, external mic pres, instruments, synths, drum machines or any (balanced/unbalanced) line signal! 

Headroom – Dynamic-range space

  • Headroom is how much room has your audio signal before it starts to get compressed and distorted.
  • Headroom – It provides buffer zone for harmonics, transients or loud sounds without risking clipping, which result a more dynamic open and wide, depth 3D sound. 
  • Also it provides space for Gentle Harmonics Distortion. 

Passive mixer side

  • -25dB insertion loss resistance (gain loss)
  • ideal for both Active (Neumann) and Passive (external micpre) work range

Drive it higher the passive side of summing mixer to achieve more harmonics & transients

  • Generate analog harmonics and hit the gentle harmonic distortion point
  • By proper gain staging from DAW can achieve the Analog Harmonics Sweet Spot

How to hit analog harmonic distortion ?

Simply boost up your DAW output Level (master fader) – and you get some “nice” distortion because you’re pushing the summing quite a bit over its nominal level  

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Transparent amp, with characteristic harmonics by legendary Haufe and Pikatron transformers. If you need something SSL style, punchy clean overall blend for final mixes, the Lawo is the best choice!

If you want colour: 
  • Add an EQ for colouring. 
  • Adding tone can massively redefine the tone of mix

Comparison test

No A/B comparison audio tests due to following reasons:

  • Your studio setup is total different like mine or others.
  • Completely different mixing strategy, different style, sound and production.
  • Can not be reproduced Your studio environment as inserts, sends, external processors.
  • Can not be reproduced Your studio setup, your monitor types, audio material, pre amp, amp, gain adjustment, cabling and so on..

There are plenty of customer feedback, please read about

Haufe / Pikatron transformers

The extremely high level handling of this transformer makes it useful as a line level input AND output in addition to being one of the best sounding  input transformers ever. The Haufe audio transformers used in some of the finest vintage high fidelity and professional German and European audio equipment, including Telefunken/Siemens/TAB/ recording consoles, Klangfilm theater equipment, etc.

The (Neumann/Filtek/Lawo or Tab/Telefunken) dual junction amplifier contains two(2) mutually independent stereo balanced audio frequency amplifiers designed for signal summation in high quality studio mixing desks. Special attention has been given in the design of the cards, to dependability and operational reliability, stability of the electrical parameters, good immunity to disturbance and crosstalk attenuation between the two (L/R) signal paths.

Fully balanced Solid State Discrete summing network. The components are tested and selected. (Vishay Dale resistors) Good quality components result  the correct and low noise operation. The summing network PCB is own development, and absolutely hand made. The front/rear panel design based on unique idea. Custom order: Unique ideas, plans like: channel number, design(your name or studio name) connections (DB25, TRS etc.) please contact me, to make the most appropriate gear for your studio! (build time depend of project size 5-20 working days)

Additional Options – Documentation – Technical Description – User Manual

Youtube videos


What’s the 2 in 1 (two in one) Active Passive?

  • this function enables to connect different kind of amplifier
  • freely can use a completely different sounding amplifier than the inside amp

There are two ways to control by A/P switch:

  1. Active mode: gain makeup by inside amp Neumann/Filtek/Lawo/NE2OX
  2. Passive mode: gain makeup by Your external micpres or DAW amplifiers

Benefits: Different amp = Different sound character

free to choose and use completely different sounding amplifier

Master Send/Return:

SEND out the master stereo to external processors like EQ, Comp, Limiter than return to master out

  • 2xSwitch version: Bypass or Enable switching
  • Auto TRS version: signal was non interrupted if nothing connected to SEND out TRS

STM – stereo to mono function

For example you may want to keep the Kick and the Bass in the middle of your mix, you would then flip the switch to UP ST1 to 1/2 for mono conversion
STM function converts signals meant to be in the middle of the stereo spectrum, converts the Stereo input L/R (two hard panned L/R Input) signals to absolute center placed real analog mono signal.


  • no need to waste precious stereo CH’s for mono instruments
  • clarity of position in the stereo field (mono is true mono)

Master Stereo to mono – Mono Compatibility switch

  • This provides an excellent way to check mono compatibility and to also learn spatial tricks from your favourite reference material.

The word ‘Mono’ is panned absolutelly 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!

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