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Filtek - Neumann follower analog summing mixer

Transparent and clean with great analog harmonic content adding depth, color, presence, character and warmth to sound mix by legendary Neumann Haufe transformers

16x2 Filtek DV1175 Summing (all style)

869 € +shipping (basic setup)

Modern Analog Sound – Neumann follower Haufe X-Formers
Basic Version D-Sub In/ TRS Out (for xlr out add 20€ extra)
  • Amp Type: Filtek BFE DV1175
  • 16 INPUT DB25 or TRS 1/4″ BALANCED
  • 1×21 Step Precision Filtek 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 50 € extra 
For XLR Out add 50 € extra

Customer Reviews

Filtek 32×2 Summing Mixer

Hi Paul, I’m Aleix! And yesterday I was testing the discrete summing Filtek bfe! And I liked very much!  Yesterday we tried it in my studio with a Digi 003 + Converter RME ADI 8 to have 16 tracks for summing! The Filtek is very clear, when mixed, it is very easy, because once everything is in place, treble and bass are more clear! I tried the SPL MixDream and Neve. And I love the SPL! But after testing the Filtek, both quality and price is amazing !!!!! So I like this new Filtek you’re building! Aleix Arcs from Barcelona


Filtek vintage summing unit – UK. 

I’ve bought one summing mixer from  3 months ago and I’m really happy with its sound (it is Filtek BFE option). This box does exactly what all consumer multichanel audio interfaces lack. I’m currently using it with M-audio ProFire 2626. What I would like to say is that this guy is real 🙂 and he’s making very nice equipment out there. Besides, he is very approachable and helpful regarding all questions and inquiries.


Studio  VAA

+1 to the above posts. I got the filtek 16 channel version to use in a fully treated project space at the beginning of the year… throw in a pair of ensembles and set focal twins and … well lets say this ‘compact’ set up blows clients of all genres away… Full stop. The clarity, imaging and tonality is simply astonishing for the outlay. An aural pleasure . If you are itb, got some nice valvie toys (and understand analogue gain staging within a daw – its amazing how many don’t!) and want to get the rich and silky console joy this is the best 500 quid you could possibly spend….IMHO (ok sprinkle a healthy few k for the other bits!)

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

No compromise 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 application:

  • 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! 


Transparent amp, with nice harmonics as a result of legendary Haufe transformers. 

If you want colour: 

  • Add an EQ for colouring. 
  • Adding tone can massively redefine the tone of mix, and sounds really cool..:)

Comparison test

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

  • Your studio setup is total different like mine or the 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 more…

Haufe 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)

Neumann follower Haufe transformer

  • AMP: Filtek DV1175 Dual mutually independent dual stereo haufe transformer coupled discrete amp
  • Dual Stereo Balanced: 1xStereo Left side /1xStereo Righ side In/Out
  • Input capability: up to 100 inputs (tech. doc  Neumann GmbH)
  • Max output gain: + 20db relative to 0dB
  • Max input gain: + 8dBm
  • Gain adjustment range:  +20dB by 21 step precision potentiometer
  • Standard level inputs:   Dual Balanced, floating to ground
  • Standard level outputs: Dual Balanced, floating to ground
  • Output impedance (load imp) : >300 ohm
  • Crosstalk attenuation: >110db from channel to channel
  • Frequency response: <+0/-0,25dB (20Hz to 20kHz: <+0/-0,5dB
  • Signal/ Noise rate: <-110dBqp
  • Extraneous signal level with V=0db : <-99dMrms/-94dBmrms with 1/30 sources
  • Input Transformers:  2xHaufe
  • Output Transformers: 2XHaufe
  • Signal/ Noise rate: -110dB A-weighted
  • TRS connection wiring: (Tip:HOT/,Ring:COLD/Sleeve:GROUND)
  • Operation voltage: 18,6 – 28V/600- 1500mA

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

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. 

“Gain staging is like pulling the focus of a camera lens”

You can achieve this by entering in the summing unit by higher levels” (from your DAW interface or synth, drum machine etc.)

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  

read more about

Filtek 24 x 6 Summing Mixer

2U rack unit
Filtek DV1175 (dual stereo balanced)
24 In DSUB Tascam Balanced input
3 x Stereo out XLR (Main/Monitor/VU) ABC
Master out ON/OFF switching control ABC
Monitor control linear poti on out B (-30dB) Vintage Black knob
Master Active/Passive both 2in1 switch
4 xStereo Multi Master Send Return DSUB ABCD post sum
*Multi Master insert with 4×2 SND/RET byp DSUB
4 x Stereo (1-8) Channel Insert Send Return by switch via DSUB
4 x Stereo to 8 Mono on 1/2 and 3/4 5/6, 7/8
Direct Monitoring (bypass summing) on input 1/2 (or let me know)
Master stereo to mono switch (mix mono compatibility test)
Phase Invert R side of master stereo signal switch
1 x 21 Step precision Filtek Master gain Vintage Black knob
Power Supply :110-220VAC to 18-24VDC PSU (EU Plug)

24 input 3 x group insert with 3 x 3 stereo to mono

Unique design custom name engraving

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