• A DIY audio dsp project.

    The freeDSP is an open-source digital signal processor family for the do-it-yourself community. The applications range from active loudspeaker concepts (digital crossovers, bass enhancement, ...) and room equalization over advanced musical effect processors to car audio signal processing.

  • Easy programmability with SigmaStudio.

    No advanced coding skills are necessary. The freeDSP works with a graphical development environment. The programming model is function-block based. Just drag-and-drop some processing blocks and virtual cables - and you are ready to go! The Windows based software can be downloaded from Analog Devices free of charge.

  • It's open-source.

    All freeDSP boards are published under a creative commons license (CC-BY-SA). It allows the unrestricted use and modification of the module. We would be happy if you join the team and improve or extend the freeDSP family. We really like the open hardware idea. :-)

Welcome to the freeDSP website. Here you can find instructions, examples, all necessary components and the latest freeDSP circuit board designs.


Audio Processing

Graphic & parametric EQs
Mixing
Phase shifting
Dynamics processing
IIR / FIR filtering
Low-level DSP functions
Real time tuning
...

Applications

Digital crossovers
Digital room correction
Subwoofer integration
Musical effect units
System equalization
Delay compensation
Bass enhancement
...

Getting started!

  • 1

    Order board and parts...

    Select your freeDSP main board from the overview table below. Additionally, you will need a programmer. We recommend building the freeUSBi programmer for real time tuning of your programms. Download the Gerber files and manufacture the board. You have to order all necessary parts yourself. We do not offer centralized buying at the moment!

  • 2

    Solder / Assemble...

    You can find the part list and the assembly print for soldering in the table below (e.g., in the corresponding getting started guides). Some soldering experience is required for SMD components. Hopefully, there will be preassamled freeDSP kits again in the future. :-)

  • 3

    Do the programming...

    The graphical development environment SigmaStudio can be used for easy programming. It can be downloaded for free (account needed) at the SigmaStudio website. Please have a look at the getting started guides to get your freeDSP up and running with SigmaStudio. For further questions please refer to the SigmaStudio documentation and forum.

  • ... enjoy!

freeDSP family overview


Main boards

freeDSP In Out Status Source Parts Documentation Compatibility Notes Cost
CLASSIC
2 x RCA
4 x RCA
Ready
Eagle, Arduino Reichelt, Digikey Getting started Only freeDSPx AES/SPDIF IN ADAU1701 65€ group buy
PiDSP RasPi In,
S/PDIF
RasPi Out,
S/PDIF
Beta-Ready
Altium BOM Getting started 3 I²S expansion connectors ADAU1452
INSANITY
8 x Analog
1 x S/PDIF
8 x Analog
1 x S/PDIF
Prep
KiCad 3 I²S expansion connectors ADAU1452
nanoDSP
2 x Analog
4 x Analog
Ready
Not available Getting started No expansion header ADAU1701 60 € + TH parts
CLASSIC SMD A
2 x Analog
4 x Analog
Ready
KiCad freeDSPx AES/SPDIF IN, ... ADAU1701
CLASSIC BAL A
2 x Bal
4 x Bal
Ready
KiCad 1 I²S expansion connector ADAU1701
CLASSIC SMD B
2 x RCA
4 x RCA
Prep
KiCad 2 I²S expansion connectors ADAU1701

Programmer

Name In Out Status Source Parts Documentation Compatibility Notes Cost
freeUSBi + EZ-USB
USB -
Ready
KiCad, Drivers Reichelt, Digikey Getting started All freeDSP boards

IO expansions

freeDSPx In Out Status Source Parts Documentation Compatibility Notes Cost
AES/SPDIF IN
1 x AES/EBU
1 x S/PDIF
-
Ready
Eagle Excel Getting started Only freeDSP CLASSIC
UNBAL OUT x8 -
8 x Analog
Tested
KiCad Only freeDSP CLASSIC SMD A
UNBAL IN x8
8 x Analog
-
Tested
KiCad Only freeDSP CLASSIC SMD A
STANDARD CONNECTOR ADAPTER
4 x I²S expansion connectors for in and out
Ready
KiCad Reichelt Getting started Adapter of the old freeDSP CLASSIC pin header to the new freeDSP I²S connector.
AMP x2 I²S expansion connector 2 x Terminal Block
Ready
KiCad Mouser Getting Started I²S expansion connector 0.1% THD @12W 4Ω
AMP x4 I²S expansion connector 4 x Terminal Block
Ready
KiCad Mouser Getting Started I²S expansion connector, two AMPs can be used on one I²S TDM 8 output 0.1% THD @12W 4Ω
SPDIF IO
1 x S/PDIF
1 x S/PDIF
Help wanted
KiCad I²S expansion connector
ADAT IO x4
4 x ADAT
4 x ADAT
Prep
KiCad, VHDL I²S expansion connector
BAL IO x4
4 x Analog
4 x Analog
Help wanted
I²S expansion connector
UNBAL IO x2
2 x RCA
2 x RCA
Help wanted
I²S expansion connector Maybe 4 Out
BAL OUT x16 -
16 x Analog
Prep
KiCad I²S expansion connector
PHONES AMP - 1 x Jack 6,35 mm
Prep
KiCad I²S expansion connector
HDMI IO < 4 x HDMI 1 x HDMI
Help wanted
I²S expansion connector
DOLBY/DTS/AC3 IO 1 x Toslink 1 x Toslink
Help wanted
I²S expansion connector

The freeDSP is so cool. :-)

Application notes


Contact

If you'r having questions regarding programing with SigmaStudio, please go to the Analog Devices support forum.


If you'r having questions regarding the freeDSP board:

  1. Please take the time to carefully read the getting started guide and have a look at the upcoming online application examples (coming soon).
  2. Maybe your issue has already been discussed in the freeDSP forum. There might already be a solution for the problem you are facing. Please use the ‘Digital Line Level’ subforum @ diyAudio.com to connect with other people working with the freeDSP. Please create individual threads for your topics. Link these threads in the freeDSP main thread - so that others can find them.
  3. Unfortunately, we cannot provide individual support via email or the contact form. Please keep in mind that freeDSP is an open-source spare-time project and not a commercial product. Thank you for your understanding! Please ask your questions at diyAudio.com and link them within the man thread.

If you want to join the freeDSP team or want to improve the documentation or the website, drop us a line in the contact form. You can also propose your applications, extensions, ... to be added to this website. :-) GitHub is used for file exchange. Most freeDSP PCBs will be designed using KiCad. Some guidelines were defined to make future freeDSP development and extensions as compatible as possible. These layout guidelines can be found in the freeDSP-Wiki.

Newsletter

Contact form