Schematics for noobs

[Marbles]

Ay.. that looks daunting :D But thank you!
I downloaded it, but am not sure how to use it. Notice that working with it on a mac seems a lot less intuitive (no toolbar), but maybe i'll get the hang of it.

Is there a place where you can download schematics to import? Would be cool is there is something like that already. Can always build it myself ofcourse, maybe that's better to learn how to use it.

[Ed Nice]

I'd never thought of Spice as a learning tool, but as Frank_NH mentioned it, I had a look and it does make sense. Thanks Frank! :)

A quick fnuroogle unearthed this: http://cushychicken.github.io/ltspice-tube-screamer/ which seems like a decent starting point, as the [Spice] schematic is supplied as well as a bit of an explanation.

I suppose the true value with learning from Spice will be the construction of [Spice] schematics from schematics or layouts, but I'm impatient ...

Every day is a school day :)

[Frank_NH]

There are tons of spice circuits all over the internet.  As far as learning, here is a good link to get you started.

http://www.simonbramble.co.uk/lt_spice/ltspice_lt_spice.htm

Just try a simple circuit, maybe a low pass filter.  Once you start getting the hang of creating and editing components, you can gradually go to more complicated circuits with transistors, fets, and op amps.

For pedal building, you can use LTSpice two ways:

(1) Create the circuits and use an unsteady voltage source (e.g. 0.1V amplitude sine wave at 800 hz) to represent your guitar signal.  What is fascinating is to observe how the simple sine wave is distorted by an overdrive or fuzz circuit at the output.  Often you can tell what kind of sound you'll get simply by looking at the waveform (it's like having a virtual o-scope).

(2) Perform a frequency sweep to look at the response resulting from a sine wave signal at the input. The frequencies of interest for pedals typically range from 50 Hz to 10,000 Hz.  This analysis can show you if which frequencies will be accentuated, and is particularly instructive for tuning tone stacks and other filter elements in the circuit.

Some examples of these kinds of plots can be found at the Electrosmash site (tubescreamer example):

http://www.electrosmash.com/tube-screamer-analysis

[motterpaul]

Check out this diagram of one of my favorite fuzz circuits. What is cool is how it shows how many different pedals really have the same layout - just different values: