Hi There,

I am using one of your product SigmaDSP(ADAU1761 Evaluation Boards).

I am also using applied program SigmaSudio 3.7 as well.

I would like to try RIAA CURVE of Phono Amp in the SigmaStudio.

I think it would be possible by using filter

but there are too many kinds of filters and a bit confusing how much I can put it on.

It would be appreciated if you could let me know how I can make it.

Best regards,

Honggi

Hi Honggi,

The RIAA playback curve starts with a first-order drop (pole) at 50 Hz, which begins to flatten out (a zero) at 500 Hz. Finally, another first-order drop at 2122 Hz completes the curve. Accomplish this with first-order low-pass filters, as shown below:

Find the filters under Toolbox/Filters/First Order/General (First Order). The first filter produces the 50 Hz transition. The response of this filter drops with frequency until at 500 Hz, the fixed gain block has more output than the filter -- establishing the second transition point where the curve flattens. The second low-pass filter resumes the slope at 2122 Hz. Embedded gains establish the overall unity gain at 1000 Hz. Compare the simulated response below with that shown under

RIAA equalizationin Wikipedia.I gave this project a quick test by playing some music first through a EQ set to approximate the inverse (recording) curve, then through this project. It sounds OK to me.

Best regards,

Bob