software simulator for audio circuit design

[Gene_Johnson]

I'm trying to locate a software simulator for audio circuit design.

I need something that not only checks tI'm trying to locate a software simulator for audio circuit design. I need something that not only checks the circuit but also produces quantifiable output regarding frequency and amplitude replication.

Does anyone have any suggestions?

Gene

[SpJonesKSU]

Try this:
Linear Technology - Design Simulation and Device Models

LTspice. free, pretty standard stuff. lots of how to's out there.

[Gene_Johnson]

SpJonesKSU thanks for the suggestion.

I’m somewhat familiar with Spice. My nephew used it while getting his EE Doctorate. We would spend hours talking about the differences in simulation software while the rest of the family would huddle around the living room screen watching some movie. And to think they would tell the two of us to “get a life.” Geez imagine that!

Spice is a nice program, but not quite made for interpreting musical equipment output.

As you read some of the DIY comments you’ll note preferences and biases which may in some cases, be a result of intervening variables. To save time and the aggravation of revisions, I just think it’s a good idea to simulate a design before building it.

With such a simulation, you can look at the output and know what to correct.

Since I looking for a specialized simulation program, I would like to think someone out there took the time to write the code. . . . . But this is not the aerospace industry where millions if not billions of dollars ride on a single circuit. There is a chance the PCB designers may be using 20 year old technology and relying on some audiophile with perfect pitch for the thumbs-up.

[SpJonesKSU]

I guess I don't understand what exactly your looking for then? How is spice not geared for music circuits? Are you looking for something to simulate the output of a guitar pick-up or the like? What's specialized about the software that you're looking for?

A simulator is only an approximation.

[godfrey]

I'm using the free version of CircuitMaker. Also spice-based. After modelling your circuit, you can poke around it with virtual instruments to check dc or rms voltages and currents, look at waveforms, frequency-response graphs etc. Includes a spectrum analyzer too, so you can look at distortion components.

[sawreyrw]

Gene,

LTspice will do exactly what you want, if you know how to use it. Hint: use the .four command.

Rick

[Gene_Johnson]

Thanks for the additional information.

I’ve used Fourier analysis to examine simple waveforms to define capacitance parameters. But I think a musical instrument is a little different. At least it looks different on an oscilloscope, as most musical instruments produce complex wave patterns. These complex waveforms are what makes music, music and that is where many of the component complains arise. For example opamps causing clipping etc.

Anyway, I envisioned a software package that first analyzes the circuit; then uses some combination of frequency modulation synthesis and subtractive synthesis to duplicate the pickups. Once this is accomplished we can start looking for clipping, unwanted distortion and so forth; then compare that to what the average person is capable of hearing and decide if the circuit is “good enough” or over-kill.

I know Yamaha has the capabilities to do that . . . but I don’t think they will send me a copy of their software.

Yes, I know the notion of defining what is and is not music is a topic that fills library shelves. But in the final analysis, defining a pleasing sound is arbitrary to a degree and the mechanics of the definitional framework is determined by the analytical tools that are available.

Thanks again guys for the information and your helpfulness. I really appreciate the information you’ve provided.

[Gene_Johnson]

Rick,

After reading your post, I responded much too quickly. I discovered there are two “Spice” programs; (B2)Spice and (LT)Spice.

When you mentioned the Fourier command, you were also referencing the LTspice harmonics iteration subroutine weren’t you?

If we are talking about the same thing, it definitely looks promising. In fact, this program looks like it’s packed full of all kinds of goodies.

Thanks Rick for your help.

Gene

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SpJonesKSU and godfrey,

Thanks guys for the help and direction. It’s much appreciated

Gene