[LAD] [LAU] Ardour MIDI tracer

Len Ovens len at ovenwerks.net
Mon Aug 18 00:44:48 UTC 2014

On Sun, 17 Aug 2014, Will Godfrey wrote:

> On Sun, 17 Aug 2014 16:15:58 +0000
> Fons Adriaensen <fons at linuxaudio.org> wrote:
>> On Sun, Aug 17, 2014 at 08:24:38AM -0700, Len Ovens wrote:
>>> So Allen & Heath uses 127 levels on their top end digital control
>>> surfaces, How do they do it? Well they have two different scales:
>>> - fader: ((Gain+54)/64)*7f - also used for sends
>>> - Gain: ((Gain-10)/55)*7f - this is preamp gain
>> Suppose you have *real* faders which have a range of 127 mm.
>> That's not far from a typical size on a pro mixer.
>> Would you ever adjust them by half a millimeter ?
>> 127 steps, provided they are mapped well, and zipper noise
>> is avoided by interpolation or filtering, should be enough.
>> The real problem is that many SW mixers
>> * don't use a good mapping,
>> * and don't have any other gain controls.
>> The latter may force you to use the fader in a range
>> where it has bigger steps.
> Well that got me thinking!
> Presumably this should be set up as a proper log law, so even if the steps
> represent (say) 0.5dB that still gives a control range of over 60dB

Actually, I got the idea that we should not only do that, but that we 
should use a gain or trim to put the signal in the area (level wise) where 
we have the smallest gain steps.

On a DAW, we sort of do this already by recording using the fader (and 
audio device gain) for trim and then mixing down using the fader for fine 
tuning. However, as I commented earlier, sometimes a harsh effect can 
introduce the need to:
- re-record the track
- add a gain section after the effect(s) before the fader. This may be as 
simple as using the output level the effect already has.

Len Ovens

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