[sdiy] Tap Tempo LFO

[John Mahoney]

At 07:56 PM 12/8/2009, Tom Wiltshire wrote:
>...
>One is that the output sample rate simply isn't high enough. It's
>only 19.5KHz, which rules out any frequency above almost 10K even in
>theory. In practice, you wouldn't get much above 2 or 3KHz. The sort
>of output rates you're talking about are 100's of KHz.
>
>Secondly, the part of this that is 'tap tempo' is the LFO frequency,
>e.g. the rate of change of some parameter. This is not the same as
>the delay time being tap tempo. For this, you need to do a different
>sum involving the clock rate of the delay and the length.
>
>It's a damn pity that it isn't do-able though, because this is
>something I've wondered about enough times myself. If you could get a
>uP to generate a clock signal for a BBD directly, you be able to do
>tap-tempo delays, flangers, chorus and the like, and you'd only need
>the uP and the delay line. None of that messing about with clock
>chips or VCOs driven by LFOs.
>
>Still, BBDs suck, so it doesn't matter, right? ;)
...

Would this work? A high frequency clock (HFC) is divided down to 
provide both the uP clock and the BBD clock. The uP is clocked at a 
constant rate, whereas the BBD clock rate is determined by a 
programmable binary counter that is programmed by -- obviously -- the uP.

Pardon me if this approach was already suggested.

John