[linux-audio-dev] [ann] unmatched - a LADSPA amp tone

[Steve Harris]

On Fri, Oct 25, 2002 at 10:15:20 +0200, Tim Goetze wrote:
> >Nope, that would be hard ;) I was thinking of having a second, hard
> >clipping alg. and bringing that in for high ampltudes.
> 
> oh yes, please keep on bringing them on.

OK, I have some pending (easy) improvements to the meters, then I'l get
onto this.

> i put in a music-dsp shaper (archive credits patrice tarrabia 
> and bram) after the inverter, and with some eq (hp basically) 
> before entering the first valve, it sounds surprisingly good.
> especially with the bridge pickup, the neck pickup is still a 
> bit muddy.

OK, time for a quick lesson - whats the difference between the pickups? My
bass (cheapish active 4 string) has two sets, a single wide one and a pair
slightly offset (they say duncan on them FWIW). There is a knob that, I
think crossfades between them.

> >It doesn't. there are no time domain effects, and it doesn't adapt to
> >amplitude - just a static trasfer function. It could be an interrelation
> >with the two valves, but I dont think so...
> 
> after some more tinkering, i guess you're right. for some
> reason, guitar notes die away very quickly with this setup.

That would be the lack of compression

> there are three issues for me with the current setup: 
> 
> * it doesn't noticeably prolong sustain.
> * the attack phase is 'flat', compared to the ringing
>   of the real thing.

OK... could this be a property of the cliping? Or is it always there?

> * the sound gets muddy and faint when you turn down the 
>   volume at the instrument, instead of keeping loudness and 
>   reducing distortion.

This is another compression effect I suspect.
 
> i suppose that these could all be improved by applying the 
> right sort of compression. i've done fairly quick tests with 
> applying gain before the first valve, and with the new 
> compressor from your set. the gain fails miserably, and i 

I think that the compression effect in a guitar amp is much faster than
what you get from a general purpose compressor. I think it is more like a
slow acting saturation. My Valve rectifier plugin (valve_rect) was an
attempt to capture that, but I expect it needs adjusting, or rewriting.

- Steve