Using wondom adau1701 in PA Active speaker
Hello,
I have some very basic newbie experience with sigma studio and wondom products.. im planning to build two way Active speakers with irs2092 amplifier and I'll like to use the simple cheap wondom adau1701 kernel board to archive a crossover.
Unfortunately I read that adau1701 as only 0,9volt input output sensivity and could be a problem if the stage mixer output will go a bit upper.
Is possibile to set the adau1701 on a professional input output sensivity value like 1,4 volts or more?
Thank you!
Audio Signal Processors
hardware
SigmaDSP Audio Processors
adau1701
Hello Jesa,
No, the DAC outputs are derived from the common mode and that is basically half of the analog supply voltage and that is 3.3V. The 0.9V is an RMS number, the peak to peak is 2.5V which as you see is close to the 3.3V max available.
what you have to do is design some OpAmp stages that is powered by +/-18V and has a lot of gain. You also can do a little filtering of the out of band energy and it is always a good idea to buffer the outputs anyway when it is going out to the real world and driving high capacitance cables etc. You also will want to make it a differential signal (balanced in the pro audio world language) which in and of itself will give you a 6dB boost.
you can look at one of our old eval boards to get some ideas. UG-45 is the user guide for the AD1938. Those DAC outputs shown have filters for a 48kHz fs and they run on +-12V so it will have decent headroom but not full professional level. Then run those into differential output driver chips.
Dave T
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