TOPIC:

I moved conversation from www.minidsp.com/forum/opendrc-series-sup...or-dacs-to-minisharc to here.

This "motherboard" for miniSHARC kit adds 6 digital stereo inputs and all 8 channels as SPDIF outputs. I have used 2 coaxial RCAs, 1 coaxial BNC, 1 balanced AES/EBU and 2 optical inputs, from which all electrical inputs are transformer-isolated. Inputs can be selected by jumper (or mechanical rotary switch) or by integrated ATmega168 microcontroller, if more complicated controlling is needed. After input selector the signal is fed to the miniSHARC by its SPDIF-input. In this specific device I have built, I have used microcontroller to imitate infrared signals to vol-fp addon card to change the filter presets in miniSHARC. All outputs are straightforward using SPDIF transmitter ICs. Clocks from miniSHARC are divided by proper clock distribution ICs.

The board has small switched mode power supply (SMPS) so it accepts wide(ish) range of input voltages. I am using 12 V which is directly fed to miniSHARC and then SMPS down-converts it to 5 V which is regulated to 3v3 by linear regulator. The SMPS can also be omitted and 5 V fed directly from 5 V wall-wart.

I used Hammond enclosure and ordered custom rear and front plates from www.schaeffer-ag.de/en/ to achieve high-quality finishing. More photos are here foto.galleria.fi/kuvat/SharcDSP/ I will update at least the front side screws when I find some fancy ones.

I was asked if I could make sth similar by order. Yes, I could. BUT. These things require so much handwork that if I wanted to get some compensation for my time, it would be so expensive that I don't dare to ask that much. I do have 6 extra bare PCBs which I can sell to fellow DIYers for affordable price. But before that, I need to run few more tests to ensure it really works. I have only quickly checked that signal comes through. In that case I also require the buyer to have good electronics skills and understand what to do. I can of course give instructions and tips for unclear things and buying the parts. I am definitely open to all comments, if there are enough interest maybe there will be next, improved revision(s). However, I won't promise anything. It is just a hobby. Unfortunately I hope something like that could become my job

It would be cool to design something similar than this but with ADC and DACs. The scheme would be similar, analog parts just need some extra precautions. 4-layer board would be the only possibility while this one is still 2. We will see, I first need to finish my 2.2 system, this is just the first component. Almost ready are also 4-channel DAC and 4-channel preamplifier

Thanks. I found you on FB and wrote message to discuss