[sdiy] Simple MIDI-syncable LFO...?

[Fredrik Carlqvist]

>The only thing that's harder about a digital design is that you have to 
>write some code. 

... and learn how the microcontroller works and the assembly language and a
development system and how to debug microcontrollers and where to get
microcontrollers and how to get the program into the microcontroller...

There are many things one must learn before the microcontroller solution is
"easier". Also, with a simple analog LFO, the huge ker_thunk can be reduced
with an LFO speed pot. And you can make a soft sync so that there is no or
at least very little ker_thunk.

The total part count is obviously lower with a microcontroller solution. It
is also more versatile. But it can be much more expensive in terms of time
(and money if you need a 16-bit DAC) and full of bugs. 


Fredrik C


-----Original Message-----
From: owner-synth-diy at dropmix.xs4all.nl
[mailto:owner-synth-diy at dropmix.xs4all.nl] On Behalf Of Richard Wentk
Sent: Monday, October 18, 2004 14:48
To: synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] Simple MIDI-syncable LFO...?

At 06:38 18/10/2004 -0400, WeAreAs1 at aol.com wrote:

>I think that a simple old analog LFO would be much more practical and
>smoother-sounding than some kind of digital LFO (as was suggested by a few 
>other
>people), plus, it would be decidedly easier to build and control.

A syncable LFO will go KER_THUNK! when it's reset. While some people might 
consider that a feature, not a bug, it doesn't look like something to be 
proud of in a design.

A digital design, meanwhile, will do wacky outrageous things like producing 
a cycle that's truly a multiple of the MIDI clock rate, no kludging 
required, with optional control of *phase* - not just frequency - if you 
want it.

The only thing that's harder about a digital design is that you have to 
write some code. In terms of on-PCB hardware it's hugely cheaper, easier to 
implement, *far* more versatile, and done properly will produce results 
that should be as smooth, if not smoother, than any analogue design.

The fact that it's cheaper means you can include more of them. You should 
be able to produce a quad design with a bank of customised modulation 
waveshapes for the price of a good VCLFO.

Richard