Best practices for audio circuit simulation

(also posted in Simulation forum, in case this is missed!)

Hi all, I've been modeling a lot of guitar effects lately (please check my public circuits list) and tend to just run a time-domain with a 1Hz sine 100mV input to simulate the guitar. For boost circuits this seems logical as I can evaluate the output signal strength, and for clipping I can see the distorted waveform...

But I was wondering what others are doing?

by geedeebee
January 07, 2014

Some thoughts.

Doing a Frequency Domain simulation (a.k.a. frequency response or Bode Plot) will show you what is happening to the fundamental and harmonics in the frequency domain.

Beware though that, in non-linear circuits, the frequency response will vary depending on the DC bias point of the circuit, i.e. where in the non-lineariity the response is being plotted.

An example of this is here:

As the current through the transistor ladder is changed then the filter response changes.

Doing time domain responses with different waveshapes (sawtooth, triangle, square) will give you more of a feel for what happens with a real guitar waveform.

Look at some real guitar waveforms and try to synthesis a simple example waveform using additive synthesis (adding up several sinusoids with different amplitudes and phases).

If you are feeling really enthusiastic you could try sampling a real signal and then convert that into a csv list that you can paste into a CL csv source.

by signality
January 08, 2014

Thanks Signality! Great advice there. I did manage to find a waveform recorded from a clean guitar here:

I've extracted the wav and have created a csv from that using Mathcad. Still have to mess with sampling rates etc and perhaps downsample, but in theory it is working. example here:

by geedeebee
January 09, 2014

Thanks again... I'll check that out too,

by geedeebee
January 09, 2014

Wow - didn't know you could do that. I'm brand new to this software.

So is there any way I can save that "V1 PWL" so as to easily plug it in to otters circuits I design?

by djryanash
January 11, 2017

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