On Sat, May 1, 2010 at 8:57 PM, Tim E. Real <[email protected]> wrote:
> On April 30, 2010 10:55:09 pm you wrote: > > Tim E. Real wrote: > >Wow, man! I just spent an hour playing with > > Guitarix Distortion (ladspa plugin) + > > caps C* Amp VTS (ladspa amp sim plugin) > > in MusE's plugin rack. > Silly me! I missed a piece of the puzzle. The C* Cabinet plugins. > I was supposed to put a cabinet after the amp. > Sounds even better now! > It now approaches the type of sound that the JCM900 vst gives. > > > > Until now I have mostly been using SimulAnalog's famous JCM900 VST > > > dll plugin under dssi-vst. (I do wish they would open-source those > > > plugs!) > > > > Aha, it's for free :), http://www.simulanalog.org/GSuite.zip, until now > > I didn't use VSTs when recording with Linux, but the web says, this VST > > should be awesome, > > > http://www.google.de/#hl=de&ei=vJLbS_jPJc6YOMjj9JIH&sa=X&oi=spell&resnum=0&; > >ct=result&cd=1&ved=0CAUQBSgA&q=JCM+900+VST&spell=1&fp=af503062d682e13a > > > I have not tried their other plugins in the suite yet, but the following > statement probably applies to them as well: > That JCM900 vst is by far the most absolutely mind-blowingly realistic > recreation of a Marshall amp *ever*. Most people agree. > It is *THE* standard by which *all* other plugins are judged, commercial > or free! > > Sadly, I just found out the hard way that it has a really nasty > denormalization problem. It's so bad I may not be able to use it any more. > People have tried fancy anti-denormalization plugins ahead of it, with no > luck, apparently. > > MusE has a basic DC anti-denormalization feature, and it didn't help. > I completely agree with you: The JCM900 VST rocks! I've been using it a lot on Windows, now I'm on the Mac, so I haven't used it in a while. Too bad the source code for these plugins is not available. The papers on the website only explain the basic principles. Anyway, I also ran into the denormalization problem quickly, so I just made a small VST that mixes some -100 dB white noise into the signal. Actually, I made the noise gain adjustable, because the added noise made my synth-guitars sound much more authentic. ;-) Alternatively one could make it more convenient to use by creating a separate wrapper .dll that loads the JCM900 and just intercepts the process-calls, while passing any other call to the plugin. Jan > Also Guitarix seems to have a slight issue too, but thankfully MusE's > basic anti-denormalization feature cured it. > (Many thanks to Robert for the painstaking work on that feature!) > > Can I get some comments on an issue nagging me for years: > Maybe I never learned some golden rule about floating point, > please correct me if I'm ignorant of some crucial technique or fact > which would help: ... > > I used to be fanatical about floating point (remember the co-processor > days?) > But I've grown to dislike it. > Bankers won't use it for calculations. > (Have you ever been stung by extra or missing pennies using a 'NUMBER' > database field instead of a 'BCD' field? I have.) > > So why do we use floating point for scientific and audio work? > Considering audio can have really small values, does it not lead to errors > upon summation of signals? > Why do we not use some sort of fixed-point computations? > > I mean take this simple BASIC program: > LET A = 0 > LOOP: PRINT A > A = A + 0.000001 > GOTO LOOP > > It produces the stupidest output with wandering errors after several > iterations. A two-dollar calculator wouldn't do that. > It plagued me when I worked with 3D drawing, too. > You move an object incrementally several times in some direction > but you can't get back to the original position by the reverse > process. That's called 'non-return-to-zero'. > > > :). > > > > On the web page there are some PDFs. > > > > Perception and Congnition > > > > A perceptual approach on equalization > > <http://www.simulanalog.org/eq.pdf> > > A perceptual approach on clipping and saturation > > <http://www.simulanalog.org/clip.pdf> Volume cranked up in amp debate > > <http://www.trueaudio.com/at_eetjlm.htm> (by Brian Santo) > > > > > > Numerical methods and models > > > > State variable changes to avoid non-computational issues > > <http://www.simulanalog.org/statevariable.pdf> > > A complete model of a tube amplifier stage > > <http://www.simulanalog.org/tubestage.pdf> > > Analysis and high performance simulation of linear networks > > Polynomial interpolators for High-Quality Resampling (Olli > > Niemitalo) <http://www.student.oulu.fi/%7Eoniemita/DSP/deip.pdf> > > > > Programming Techniques > > > > Optimizing with SIMD instructions > > <http://www.simulanalog.org/optimization.htm> > > Compiler Benchmarks <http://www.simulanalog.org/compiler.htm> > > > > I have little use for it, because of a lack of knowledge, dunno, perhaps > > it's useful for some people from the list. > Yesterday I took some time to read some of those papers. > Fascinating stuff, especially when presented with an audio effects/amp > simulation goal in mind. > > Tim. > > > > > Thank you for the information Tim :), > > > > Ralf > > _______________________________________________ > Linux-audio-dev mailing list > [email protected] > http://lists.linuxaudio.org/listinfo/linux-audio-dev >
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