OK, I got it. Capacitors 'store' charge. Too bad, the effect is
nice.
So if I was to buy a Boss delay and MOTMize it, would it be hard to
match
the power to MOTM?
Mike
--- In motm@y..., "Paul Schreiber" <synth1@a...> wrote:
>
>
> > Again, coming from a total electronics dumb-bell, with such small
> > delay times couldn't you do this with discrete parts?
>
> Not really. You need to have several steps:
>
> 1) Conversion and storage means on the incoming audio. A BBD chip
is a black of many small
> capacitors (like 512 of them). There are 512 analog switches
inbetween them. The audio (AC
> voltage) is "dumped" on a capacitor.
>
> In digital delays, the audio runs through an ADC (analog-to-digital
converter) and the sample is
> stored in RAM.
>
> 2) Output conversion means from storage to audio. In a BBD, this
is "free" because you are
> retrieving the original charge (OK with added noise and 'droop').
In a digital delay, that is
> done with a DAC (digital-to-analog converter).
>
> 3) Clocking means. This "shifts" the sample along in the storage
means to get a delay. If you
> have 512 BBD stages, and you want 5.12ms of delay, that's...errrr...
(looking for slide
> rule/MathCAD/abacus) a clock period of 10us or 100Khz. Most BBDs
won't operate this fast, which
> is why you see "minimum delay" in the 10ms range. In the digital
world, we can go
> full-tilt-boogie and "cheat" by picking off from ANY RAM location.
A BBD has fixed "taps" and so
> we are forced to chug through the whole thing.
>
> Paul S.