[LAD] [MusE-user] De-normals. (Was A small article about tools for electronic musicians)

[Tim E. Real]

On May 1, 2010 08:10:27 pm Tim E. Real wrote:
> On May 1, 2010 07:14:41 pm you wrote:
> > On Sat, May 1, 2010 at 8:57 PM, Tim E. Real <termtech at rogers.com> 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&resnu
> > >m= 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. ;-)
>
> Ha! Sounds good. Authentic hiss!
>
> > 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
>
> I tired a quick mod in MusE to do what the author of the caps ladspa suite
>  did to handle de-normals. He said "A -80dB signal at the Nyquist frequency
>  or lower". No luck.
> But yeah, obviously at some signal level and type, it should stop.
> So I'll keep trying. Noise sounds like the best way. -100dB white to start?
> OK...
>
> Ugh. A new MusE options panel: Advanced de-normalization options, he he...
>
> Cheers. Keep on rockin'.
> Tim.
>
> > > 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!)
> > >

(CC'd MusE user list.)

Hey thanks for the tip Jan! Right on!
It worked! Man that is one SOB that's been plaguing me for a while.
I didn't realize what was causing it until the other day.

Turns out Guitarix needed more than just the DC, it needed the noise.

-------------------
To MusE users: No MusE mods required. Here's the way I did it:

To avoid taking up an effect rack slot on each affected track, create a new
 Audio Input track with inputs not connected, with a single white noise 
 ladspa plugin in its effect rack, say the caps C* White noise.  
Set the plugin's noise level to the second least value available, like 0.01.

Un-mute the new Audio Input track.
Name the track 'Noise source', let's say. 
Set the track level slider to -59dB, *NOT* -infinity, which causes the symptom.
(That's the second least default minimum slider value, settable in options!) 

Now add 'Noise source' to each affected track's input routes, aside from any 
 routes they already had.

Note that if any Wave track effect rack plugins require the noise added, 
 there's no way to inject the noise to their effect rack unless the Wave 
 track's record-arm is on.
So do like I usually do anyway... route your Wave tracks to Group tracks,
 and put the plugins in the Group tracks.
Similar for other tracks like Synth tracks. Route them to Groups.
Then inject the noise into the Group tracks.

Well, you get the general idea I hope.

Now things should be ready to roll smoothly.

It's striking to adjust the 'Noise source' Audio Input track slider level 
 to -infinity and all of a sudden things freeze and slow to a crawl.

Don't do it!

Tim.