Tonefiend Forum

Fantastic idea Larry! I don't have an electric with me at the moment or I'd 'chip in' some samples. I just started tinkering with LTSpice a couple weeks ago, but I'm still figuring it out. I would be really interested in building up a file repository of different circuits to tweak/adapt/combine. I have a few websites and could easily create a repository/project type system if people would be interested (unless Joe wants to do add something here).

Cool. I've been going over those schematics. I've been blessed/cursed to know a lot of brilliant electronics guys who have always solved my problems for me, so I'm still learning the basics for myself. So far, I've been using spice as a little project board for simple circuits to learn the different functions. I've grabbed some lib files from the yahoo group, but I haven't attempted any 'full' pedals yet or done any audio simulation. I think I'm just going to start by plotting out all the demo's from Brian Wampler's book and Joe's circuits and then mod from those.

Here's the complete tube amp schematic etc. from the YouTube video. Should include the WAVE input and output. I haven't tried an audio simulation through LTSPICE myself yet either!

https://rapidshare.com/files/3277695653/Hi-OCTANE.zip

Okey Doke. I got it all working. A couple notes.

1.When I added the standard cap and diode to the 9volt, it doused my signal. So since its unnecessary for simulation with the clean 9v, I removed it, but I'm not sure why it did that.

2. make sure that you install the full 'standard' library of components because the stock selection is pretty minimal. I've included the most recent zip in the attached file, but you can get the updated packs from the yahoo group in the future. Unzip and overwrite the files in your lib/cmp directory.

3. It takes a long while to run the simulation. My laptop was processing at about 115ms per second. So its best to keep the audio file short. I initially set things up to do multiple passes with my pots at different values. While it processed things x times, it only saved one pass to the output file so I need to figure out what that's about. So until I figure that out, I suggest just setting fixed values, running, change values, run again, etc.

If you want to do multiple passes, Add a variable in the pot settings ex. "Rtot=50K wiper={wip}"

Then create a command line such as:
".step param wip list 0.2 0.5 0.8"

It will do a pass with the pot at each of those settings

If you just want a fixed wiper setting (at 80% for example), then the pot setting would be:
"Rtot=50K wiper=0.8"

4. I did a simple transistor boost which worked great and gave a soft distortion. I plotted the fiendmaster, but the output is muted and odd. I suspect it is the germanium transistor but I could have just screwed something else up. According to various threads, no one seems satisfied with the way that AC128 is modeled. So I'm going to leave that alone for the time being, but I'd encourage you, or someone else smarter than me to take a look at the file and see if I did something wrong or if the transistor model is just bad.

I've uploaded my files here: https://www.dropbox.com/sh/syykyqweb86pf5s/TOB9I7Mk9v/spicefiles.rar

I set them up similarly to the ax project so the main I/O are on the bottom and the commands are on the top. You can just delete all the stuff in the middle and connect to the power/input/output to test a new circuit. I'd still like to figure out if there is a command to have it write multiple passes to the same file. I'm just using a short guitar clip I had laying around, but it's definitely not a good test clip. Feel free to replace it with something better or just change the input tag to call the sig generator instead of the guitar (change the circuit input tag from 'guitar' to 'siggen').

Alright, that's my progress for the night. I'll try a more detailed circuit soon. If you can figure out where I went wrong with the fiendmaster, that would be awesome.

Scott (less formal than smgear)

sorry man, Thanks for the feedback. Talk about a rookie mistake on the ground lead. My simple OD ran at around 115. The fiendmeister was about 85. The Hi Octane was crawling. I'll see if I can get the fiendmaster running now.

I've been working on some other schematics, but it doesn't appear that there are very many decent models floating around for a lot of common opamps. So I'm not sure if it is worth the effort to model the more advanced circuits for analog modeling purposes. Regardless, it's a good learning experience.