signal processor

This is an updated version of my old miniD preamp from 2014 combining miniDSP and 4-channel DAC-preamplifier

Small 4-channel preamplifier with digital signal processor and digital-to-analog converter
- DSP can be used for crossover for 2-way speaker or between speaker and subwoofer, and/or digital room correction
4 digital SPDIF stereo inputs and one analog input
4-channel unbalanced analog output
DSP-solution consists of ADAU1701-based miniDSP-board and applicable software
Atmel AVR-based firmware with extensive features such as IR-remote, balance, offset for inputs and outputs, DSP bypass, selection between analog or digital volume control, etc.
Main components: SRC4392 SPDIF-receiver and sample rate converter, miniDSP-board, PCM4104 DAC, OPA1662 op-amps and PGA4311 volume control

Digital signal processor designed for my 4-channel DIY system.

6 digital stereo inputs: 2 toslinks, 2 coaxial RCAs, 1 coaxial BNC and AES/EBU (XLR)
4 coaxial BNC stereo outputs offering 8-channel output where channels are mixed/filtered from two input channels
All electrical connectors are transformer-isolated
Can be used for crossover filtering for multi-way active speakers, parametric equalisation, digital room correction; filters are given in parameters (PEQ), biquads and/or FIR coefficients; also includes level, delay, polarity, compressor/limiter
DSP-solution from miniDSP: miniSHARC OEM/DIY-board and miniSHARC plugin software; outputs with CS8406

Note that this is one of my “old” projects and is kind of obsolete. I do have bare PCBs if someone wants but I have no intentions to further develop the design, documentation, or measurements, which are not really comprehensive. However, the device was fully functional so feel free to pick tips for your own implementation.

miniD Preamp – Tiny miniDSP-based 4-Channel Preamplifier

SharcDSP – miniSHARC-based 8-Channel Digital Signal Processor