[sdiy] digital delay, was ...

[Glen]

At 11:43 PM 9/11/03 , phillip m gallo wrote:

>It was also a common hack to wrap a NE572 around either the Phlanger and the
>RS "Reverb" to bring the noise issue into the realm of the useable.

Here's a bizarre suggestion:

Place several delays in parallel, to reap the noise reduction benefits of
using multiple channels, as we discussed in a recent thread. When you get
tired of doubling the number of units to get another 3dB of S/N, then
things get really unusual.  :)

All these delays will be built with dual-section chips, such as the
SAD1024. The desired signal only flows through one half of the chip. The
other half of the chip is used as an "empty" second channel. In other
words, make a stereo delay unit, but only use one channel for your signal.
Using dual chips keeps the two channels fairly well matched to each other
in frequency response, noise level, etc.

What about the other channel? You let a computer analyze the noise coming
out of the "unused" channel, and then subtract the spectra of that signal
from the channel with the desired signal.

That's right, I'm suggesting to use a high quality ADC, a fast computer,
and a high quality DAC to digitally process and remove the noise from the BBD.

I told you it was a bizarre idea.

I guess my mind has been wandering a bit, trying to think of something
original to use my BBD chips for. I guess this idea might be original, but
now I need to think of something that would be both original and useful at
the same time.  :)

I also just realized that this bizarre suggestion gets us back into the
territory of a digital delay (by way of the Twilight Zone).   :)

later,
Glen Berry