Software simulation

[saj888]

Hi all
Is there any software that i can use to analyze the signal and dc current current flow in a audio power amplifier. Can i feed an amp schematic into the program to analyze the circuit?
Thanks

 

[ximikas]

Hi , recently microcap become free . Also there is ltspice . You can use them to check ac dc voltages,currents , frequency response ,measure distortions and so on . But you must repeat schematic there from the components it has ,or add ones which not exist there,you need to find then spice models then . If you searching for software where you just supply any schematic file in some format and can instantly analyse ,i don't know such .

 

[jan.didden]

There is a thread here about starting to use LTspice, with examples and lots of people ready to help.
https://www.diyaudio.com/community/...nner-to-advanced.260627/page-158#post-6850421
Jan

 

[steveu]

It started with Pspice but it had a limit of ~10 transistors per schematic unless you bought the professional version. Today LTspice provides a free software tool that has no such limits and therefore has become the standard. It comes with models of LTC products and some common transistors and other parts. Key to using LTspice is importing 3rd party models. Most semiconductor manufacturers provide free spice models for their products on their web sites. You can add these to the model library files in LTspice or just put a reference to the 3rd party files, or your library collection of such files on the schematic. The models are (mostly) standard ascii text files that can be concatenated together to create a library of part models. This is better because then LTspice updates do not mess with your 3rd party files. There are also a few DIYA members who have model library files available on their web sites and you can access them directly with a link on your schematic. These include Bob Cordel and Minek. There is a thread in DIYA that discusses how to use LTspice. In some cases, you will not find models for obscure parts, but by choosing a similar part model, you can still get a very good simulation. Making your own symbols and models is a bit complicated, but LTspice has done a great job of making it easier. Part models are never perfect, and Bob and others have created improved models of certain parts. It is common for some op-amp models do not model the power supply pins properly, but I have never seen that problem with LTC models. Rarely, models are just broken. There are many advanced features to LTspice such as temperature and Fourier transforms, so don't expect to master it soon. There are YouTube video tutorials.