On 22/04/2012, Richard L. Hess wrote:

> Hi, Jan,
> I have both DC6 and DC8 but have not used DC8's click repair as I
> never really liked DC6's.
> As I said, my experience was on a very bad LP and there was no
> comparison to DC6 or the Samplitude product. I only tried a little
> with DC6 as the Samplitude product always worked better for me.
> It is a mixed bag, but for the price ($40?), I would try Brian's
> little program. You can check the price at the website
> It was less than the upgrade to DC8 when it was on sale, and I haven't
> used DC8 except to try it and not see a huge improvement in noise
> reduction over DC6. Maybe, I'm missing something. I think Brian's
> tools are a great addition to the toolbox, both denoise and
> clickrepair. Also EQ. Your mileage may vary. I have not tried Izotope
> recently. It had promise, but it didn't offer an improvement for me
> for my tape work. I have not evaluated it for disc work as that's not
> my main business. I've just fallen into a dozen or so LPs recently
> that people wanted me to do as part of larger packages or 'cause they
> are friends willing to pay. The real noisy one I just did for a
> friend.
However, LPs don't normally have crackle as 78s do. They tend to have
fairly widely spaced individual clicks (which 78s have too).

I would describe crackle as a multitude of small clicks at random
intervals of many times per second. Generally the clicks differ on the two
walls of the groove. (LP clicks are more often on both walls.)

As each little click is an impulse, it has a wide-band spectrum covering all
audible frequencies, so no kind of frequency-based filter can remove it.
However, the spectrum goes up higher than that of the music, and this
can be used for detection if the sample rate is high enough.

Groove wear is another problem again.

Don Cox
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