Introducing dsprak™ High Performance Audio

dsprak inside the box

Danville Signal’s dsprak™ high performance audio platform is a semi-custom solution for OEMs. Optimized modules are combined with a custom motherboard to create a no-compromise platform that meets specific customer requirements.

• Optimized High Performance Audio Module
• Expandable to 32 Channels
• DSP Concept’s Audio Weaver Support
• dspblok 21369zx (ADSP-21369) DSP Module
• Two Channel ADC Module (AKM AK5394A)
• 8 Channel DAC Module with Analog Attenuators (AKM AK4396 & Cirrus Logic CS3318)
• 8 Channel DIT (AES 3id/SPDIF)
• 8 Channel DIR with ASRC (AES 3id/SPDIF)
• Low Phase Noise Clock with Word Clock Sync

dsprak from the right

The basic 1U system supports 2 to 8 analog and digital inputs and 8 analog and digital outputs. Additional motherboards can be stacked to create larger systems with up to 32 channels.

Danville engineers are available to discuss your instrument requirements. Or you can start the process by completing our online Request for Quotation form.

USB Audio Class 2

Music delivery systems are rapidly changing. The days of a CD changer and a huge library of CDs is quickly being replaced by a computer with the content residing on a large harddrive.

Unfortunately, the internal soundcards in most computers are not nearly good enough for the demands of high quality audio.

USB Audio Class 2 has become the interface of choice for extracting the digital content from the music server computer to a target DAC or headphone amplifier. This is a relatively recent development. Although USB audio has been around since the early days of USB, it was basically a 48k, 16 bit stereo interface (USB Audio Class 1.1). USB Audio Class 2 can support multiple channels at high sample rate and full bit depth. It uses an external clock from the USB client that helps insure minimal jitter at the target device.

The leader in USB audio class 2 chip solutions is XMOS. Danville Signal is a third party partner with XMOS. We have utilized and extended their technology in several ways, primarily by combining their chips with Analog Devices' SHARC DSPs. This allows the XMOS device to concentrate on communications while the DSP to manages signal processing and control.

An audio class driver is mostly concerned with streaming audio data at various sample rates and bit depth. It has limited control, such as volume up and down. Danville has extended the control capability of our XMOS targets by appending a HID interface into the XMOS code. This allows us to download code or instructions to the DSP or interface to a graphical design and tuning interface such as DSP Concepts' Audio Weaver. We supply a Window DLL so that custom programs can be easily created to take advantage of these features without the need to be an XMOS programmer.

There is native USB Audio Class 2 support for Apple and Linux. Microsoft has not opted to provide similar support with their operating systems. This may be because USB Audio Class 2 places demands on the computer that not all PCs can support. We have driver support for Microsoft Windows (XP, 7 & 8). We provide these drivers with our general purpose dspblok modules such as our dspblok 21479u8a and with our more dedicated targets such as our wireless audio transmitters.

If you are considering your own design, we suggest you consider our dspblok 21479u8a. This module combines an XMOS XS1-U8A processor with an Analog Devices ADSP-21479 DSP. We use this module in many of our turnkey OEM audio products. With the dspblok, you don't need to program the XMOS device at all (XMOS programming is tricky). You also get Windows driver support. If you are interested in a more custom solution, we can provide a complete hardware and software package with optional graphical design and tuning capability. Check out the dspblok 21479u8a page for more information.


dspblok 21479u8a Xmos DSP Audio Class 2 dspblok 21479u8a
XMOS-SHARC Audio Class 2 Solution


dspMusik 2/8 Multichannel DAC

  • Up to 384 kHz sample rate
  • S/N in excess of 120 dBA
  • Balanced/Unbalanced I/O
  • USB Audio Class 2
  • Analog Devices SHARC DSP
  • Low phase jitter clocks
  • AKM DACs
  • Optional analog input module
  • Optional custom configurations

The dspMusik™ 2/8 is a stereo in, eight out multichannel DAC platform suitable for high performance DSP loudspeaker crossovers, music decoders and many other high quality audio algorithm applications. An LCD/Encoder provides source selection, volume control and access to special features. You can also use an Apple Remote for control.

Semi-customizable, Professional Audio Converter Platform

The dspMusik 2/8 platform delivers audiophile performance, featuring state-of-the-art components from Analog Devices, XMOS and AKM. Each part has been carefully selected to build a precisely integrated system.

The dspMusik starts by using low phase jitter clocks driving all the data converters. The optional ADC incorporates very high common mode rejection / low noise balanced inputs and DACs with minimum phase anti-imaging filters (desirable to avoid pre-echo effects). Signals are processed by an audio-optimized 32-bit/40-bit floating point DSP capable of up to 384 kHz performance.

Audio Weaver Programming Software

The dspMusik 2/8 is supported by a custom version of DSP Concepts’ Audio Weaver™ programming software. This is a powerful graphical design package that lets you create your signal processing chain by simply dragging and dropping highly optimized audio processing modules. You can use any of the dozens of pre-built audio functions—EQs, crossovers, mixers etc—or enhance and combine them with your own custom processing to create precisely the functions you need. Once the design is done, the file can be directly saved and run stand-alone on the dspMusik platform.

  • PC-Based Development Environment
  • Drag and Drop Signal Processing
  • Over 400 processing Modules
  • Real Time Tuning and Profiling
  • Visit for more info

Audio Weaver Software Screen Shot


OEM/ODM Customers

The dspMusik 2/8 platform is available in a variety of configurations including PCB assemblies where you provide your own housing, or it can be provided in an extruded aluminum enclosure. Panels can be rebranded with your company’s logos and trademarks to fit your company’s specific requirements and branding. Danville also provides customized display software that includes your company and product name as well as access to special features that may be part of your system design. Contact us to discuss your project needs.


dspMusik 2/8 features:


  Analog Devices SHARC ADSP-21469 or  
  Analog Devices SHARC ADSP-21489


   USB Audio Class 2: XMOS 
   SPDIF Digital Input
   Optional Analog Input Module:
       ADC: AKM AK5397 (S/N > 120 dBA)

   DACs: AKM AK4495 (S/N > 120 dBA)
Configurable Input / Output:
   Balanced or unbalanced circuits
   Consumer (-10dBV) or Pro (+4dBu) levels
   Standard 6.3mm TRS connectors
   Optional Tascam style DB-25 connections
Operating System Support:
   Microsoft Windows XP, 7, 8 &10 (included)
   Apple OS X (native support)
Input Power (Complete Version)
   IEC Mains Connector
   Autoswitching 115/230VAC, 50/60Hz


dspMusik 2/8 Options

dspMusik 2/8 Complete

Includes ADC, UAC2, S/PDIF & Display/Encoder powered by dspblok 21469uac2
P/N: A.03708E-469-AD-DE

Includes ADC, UAC2, S/PDIF & Display/Encoder powered by dspblok 21489uac2
P/N: A.03708E-489-AD-DE 

OEM/ODM Options:

There are many OEM/ODM options including individual board assemblies, power supply adapters for Pascal & Hypex power amplifiers, 16 channel expansion cappability and alternative dspblok modules with OEM/ODM quantity pricing.

Contact Danville for available options.



dspMusik 2/8 Multichannel DAC


dspMusik 2/8 Interior View 

Download the dspMusik 2/8 Multichannel DAC Platform Datasheet


Download the dspMusik 2/8 User Manual  



Snowbird DSP Crossover

The Snowbird family of Danville’s dspCrossover products are primarily intended for manufacturers of powered loudspeaker applications such as professional studio monitors and high end consumer audio systems.

Danville has a reputation for great sounding DSP crossovers. Obviously, this starts with great parts. The Snowbird uses an Analog Devices’ floating point SHARC DSP as the processor. SHARC DSPs are the gold standard for high performance audio processing. The DAC & ADC functions are provided by an AKM Velvet Sound codec operating at 192kHz. The Velvet Sound data converters are recognized as the best in the industry by many audio pundits.

Even though the Snowbird family DSP Crossovers have high performance expectations, they are priced competitively when compared against other DSP crossover solutions that rely on highly integrated, but lower performance parts. Danville has its own automated SMT manufacturing line in the United States, that helps us keep costs down and flexibility high.

Snowbird DSP Crossovers are dependent on a mating power amplifier for its power. We currently have support for amplifiers from Pascal, Hypex, ICEpower and Powersoft. Each of these amplifiers have their own specific interfacing requirements. Danville has mating adapters that convert these requirements to the DSP board so that cabling is straightforward and control features such as mute, standby and fault protection are addressed.

There are many different Snowbird configurations. The basic feature list for the models described in this manual is as follows:

• Analog Audio Inputs (1 or 2 channels, Balanced XLR)
• Amplifier Outputs (2 or 4 channels)
• S/PDIF Input and buffered S/PDIF retransmitted Output (optional)
• USB Control Port for programming and field updates.
• Toggle Switches for user defined controls

Once we understand your specific requirements, we provide the configuration that makes sense for your target. This works well since we only provide these crossovers to OEM customers. This would be very impractical for a DIY customer base.


The Snowbird DSP Crossover comes pre-installed with DSP Concepts' Audio Weaver. Danville has a licensing agreement that allows you to design and distribute your product without buying additional tools or licensing. All you need is a Windows computer.

Audio Weaver is a graphical design program that includes hundreds of optimized modules. Systems are designed in a drag and drop fashion to create signal flow. Audio Weaver runs natively on the SHARC DSP with optimized production quality modules. You design the signal processing system without the need for custom programming. Once you have your layout, you can adjust parameters in real time. For example, you can create a crossover design, make some measurements and listening tests, and then adjust parameters to fine tune the system without interruption of the test source or music.

One of the features we really think is important is that Audio Weaver includes a complete set of high performance filter modules. The precision of these modules is extremely important when creating filters with high Qs and low frequency corners, a.k.a woofer adjustments. There can be a 60dB signal to noise difference between an ordinary filter and the special high performance filters built into Audio Weaver.

DSP Crossover design might seem a bit daunting at first. As part of our support program, we will help you get started by providing live training via Skype. We will also discuss signal flow architectures choices such as IIR versus FIR, bandsplitting options (Butterworth versus Linkwitz-Riley) and other useful features. After all, we want your loudspeaker to sell well. We sell a crossover every time you sell a loudspeaker.


2017 ALMA Presentation

DSP Crossover Implementation and Design - by Al Clark and Paul Beckmann


Snowbird Manual available upon request.

Wireless Audio

The wireless revolution has been in full force for several years. Many of us use wireless connections for computer networking, hands-free cell phone communications and many other day to day activities. We all get the benefits of wireless connectivity.

So why has high quality wireless audio been missing?

The short answer is bandwidth. High quality audio takes lots of bits delivered in a timely consistant manner. Unlike WiFi, you may not have the opportunity to retransmit the data again if the data fails the first time.  The second, less obvious answer is economics. Let's explore each of these in turn.

Most wireless audio solutions aim very low. The thought is that convenience is everything and that 16 bit 48k stereo is more than enough. Anyone who has listened to MP3s understands this point of view. Suffice to say, this is not an area that we are interested in pursuing. 

If you set the bar much higher, then it is reasonable to require higher sample rates and certainly much wider bit depth. This limits the playing field to only a few candidates. If you also extend the requirements so that multichannel solutions are supported, then the field narrows even more. Imagine you would like to support either wireless surround sound for a home theatre application or a system with multiple subwoofers for a stereo application or both?

Summit Semiconductor has a premium wireless audio platform that meets these basic requirements. It supports up to a 7.4 system, sampled at 96k and 24 bit uncompressed bit depth. The Summit solution uses 24 RF channels in the 5-5.8 GHz band. It is adaptive to minimize interference from competing wireless solutions. 

This is a great start and the basic solution is supported by an industry consortium called WiSA (Wireless Speaker & Audio) Association. 

So it would seem like Summit has done a great job of addressing the "bits" problem and they have. But there is still more to creating a great wireless audio system and this is where "economics" comes into play. If we can insure that bits are delivered error free, then any platform, wired or wireless should have equivalent results given the same sample rate and bit depth. This is true as long as the bits arrive at precisely the right time. The right data at the wrong time is the wrong data!. This is why jitter performance is so important. If the data stream is improperly sample rate converted, you can permanently encode jitter into the stream and this cannot be fixed. If the data is correct but not jitter free, it can be fixed by jitter attenution techniques.

So lets get back to economics. If you are a chip manufacturer, it follows that you need to sell your products to a sufficently large audience. This means that you will need to create a sufficient least common denominator of features, performance and cost that insures that your devices are both affordable and meet the primary needs of your target audience. Summit has done this quite well. But due to economic realities, there is more that can be done.

Danville wireless audio technology uses SHARC DSPs and very low phase jitter clocks to complete the solution. There is a SHARC DSP in our transmitter implementation and SHARC DSPs in each receiver circuit. The SHARC also implements our dspCrossover functions. We complete the process with high quality DACs and related single conditioning circuits. 

At the 2013 CES show, we had a well known audio reviewer state that the wireless speaker we were showing was a wireless system that didn't sound wireless.  Isn't that the way its supposed to work?

Our wireless audio implementations are available to loudspeaker manufacturers. Let's start a conversation.

WiSA Member - Danville Signal

Danville Signal is a WiSA Member

Learn more about the WiSA Association  here. 

High Performance Audio

The world of high performance audio is changing. Sure, you can still find vinyl enthusiasts and advocates for 10 watt triode amplifiers, but you will also find many more listeners that are taking advantage of newer digital technologies. What they all have in common, is that they all want great sound.

Danville Signal is uniquely positioned in that we are a partnering company that has extensive experience in both DSP (> 20 years) and high performance audio solutions (> 35 years). We are active members of Analog Devices and XMOS third party partner programs.

Here are a few of the application areas that we address:

  • DSP-based Active Crossovers
  • High Performance Wireless Audio
  • USB Audio Class 2 DACs and Headphone Amplifiers
  • Bass Management
  • Room Correction and Beam Forming
  • Vinyl to Digital Converters (Translation Phono Preamplifiers)
  • Algorithm Decoders and Demo Systems

The bulk of our audio products are semi-custom solutions tailored to individual customer requirements (ODM & OEM). You probably won't see them on this web site, but they are in brands you know. We invite you to start a conversation.

We also have off-the-shelf products that perform well, but are not fancy. These may be useful as take off points or repackaged to fit your needs.


© Copyright 2003-2018 Danville Signal Processing, Inc. All rights reserved.

Danville Signal Processing, Inc.
29687 82nd  Avenue Way,  Cannon Falls, MN 55009
Phone: (507) 263-5854 - Fax: (877) 230-5629