towards stateful saturation – very first audio shots

Around a year ago or so I’ve already started to look into a couple of stateful non-linear models which could be more suitable for a musical and convincing digital saturation experience. To make it even more harder, they should avoid the usual drawbacks such as huge latency or insane cpu consumption – if ever possible of course.

Meanwhile, my journey into the non-linear DSP land has made an important stopover with a first prototype implementation for such an approach, yielding a DSP core for musical harmonic distortion generation based on a stateful model. This opens the door for quite a number of interesting applications such as harmonic exciters or devices which needs convincing amp models whether thats a compressor output stage or even part of a guitar amplifier effect.

those sexy curves again

proportional EQ curves

What constitutes those smooth sounding equalizers some are raving all about? In fact the answer is pretty much simple but maybe disenchanting to someone else: It’s in the equalizers transfer curve and (almost) nothing else. That equalizer transfer curve determines the actual frequency and phase response and generally speaking, in an analog filter model the frequency response implies the according phase response (and vice versa). In the digital domain this holds not true in general as shown by linear phase filter implementations. Additional effects like the actual transient response or additionally generated harmonics are then the icing on top (if desired) but may appear quite subtle or even negligible if we just look into rather transparent devices.

introducing NastyDLA

There are just a few audio effects available that are capable of instantly turning a small and wimpy riff into something big and meaningful. One of them is the classic chorus/echo combination. Beside the individual classic echo or chorus devices these combined devices were historically build around true tape or bucket brigade delays.

From today’s production standards perspective they might be easily overseen (feature wise) but on the other hand they are still pretty much demanded due to their specific and warm tone and this unique sound quality is probably the charm which still today attracts producers and audio engineers to use them in their actual music productions.

NastyDLA is going to follow this path and recreates all the specific tone qualities while adding just some few but well selected modern features. The plug-in implements some of the most distinctive and much appreciated sonic effects generated by these devices:

• classic chorus and echo effects
• authentic signal path coloration
• tape-delay style feedback and saturation

NastyDLA applies gentle feedback driven delay effects, performs smooth audio signal modulations and adds extra harmonics and saturation effects. It will be available as a freeware VST plug-in for Win32 compatible systems later this autumn.

related links: the classic chorus echo device