LTspice

[Andy Le Blanc]

I've been noodling with some basic sand circuits, NPN common emitter transistor, kinda fun...
In the process I stumbled over a freeware program called LTspice IV.

pretty usable, even for me, I'd rather have graph paper, A couple tutorials on the Utub were a big help too.
Seems to be a nice workable program, takes a good deal of the guess work out, and its free...

great for fx guitar pedals....

[martin manning]

Hi Andy, I'm pretty sure there are a number of folks here who are using it. I have both the Windows and Mac versions running. There are tube models available too, and those have been improving over time. The newest one, released just a week or two ago, claims to model secondary emission, and there is a program available to create and match a model of this type directly to curve tracer data taken from a real device.

[Andy Le Blanc]

pretty cool... I'm just glad its freeware, the last freeware thing I came across that was really useful was the rightmark analyzer package.
Keeper cheaper...

[rsi]

It'd be nice to find some libraries specifically for amp/pedal stuff. Like at the Hoffman site they've got all kinds of stuff for ExpressSCH and ExpressPCB. Unfortunately, those don't work with LT spice.

[Tillydog]

Steve Bench over on DIY Audio has a valve/tube library that I have found to be extraordinarily accurate for 12AX7, 12AU7, EF86, EL84 & 6V6 - it's done as a drop-down menu which makes it a breeze to use.

There's also a selection of output transformers there, but I can't vouch for them.

IIRC there's a sticky in one of the forums.

Edit: Actually they are all here (look at the stickies):

http://www.intactaudio.com/forum/viewfo ... 53b86c2448