[sdiy] MIDI HD

[Tom Wiltshire]

GB,

> One could, theoretically, let a person choose their update rate and precision (#bits) in some setting. Either globally or per control. The first time I encountered this was in a go-kart speedometer (data logger). Every time the axle goes around you can calculate a new speed/period. Then asynchronously, you can determine how often to show this to a user.  Maybe even filter it with past values so it's not so jumpy.

Absolutely. Like your go-kart example, I've seen something similar on yacht wind speed gauges. You can set the length of time the gauge averages over  before it presents you with a figure. Usually this is taken to be synonymous with update rate, though it isn't. You could have a long-term average that is updated every 0.5 sec if required, but I've never seen it done.

> So with a synth you could set the bit depth (7 bit, 14-bit) and max update rate. Hard to say if it's worth it for the 1% of end-users that would use it.

That's probably the crucial point. It's a niche feature.

> Also, not only digital filtering, but analog low pass filtering on the derived CV's if there is analog stuff in the end sound source.  Like the S&H caps.  But whether analog or digital, this will introduce slight response/lag. Not that it's necessarily a bad thing…

There's a limit. If your shortest envelope curve is 1ms, then perhaps you should set your filter to allow that to pass without too substantial distortion. Similarly for LFO edges - how fast do you want a square wave to rise from the bottom to the top? You can decide these figures and set filters accordingly, or if the processor can't keep up, do it the other way round - e.g. modulation CV samples are going out at 2KHz, so filter can only be 1KHz max, and 500Hz would do a better job if we can cope with that.

Regards,
Tom