Re: [ARSCLIST] Non-RIAA preamp

[steven c <stevenc@xxxxxxxxxxxxxx>]

----- Original Message ----- 
From: "Richard L. Hess" <arclists@xxxxxxxxxxxxxxx>
> At 03:30 PM 9/11/2006, Don Cox wrote:
> >On 10/09/06, phillip holmes wrote:
> > > In the phase encode/decode discussion of RIAA, did anyone mention that
> > > speed is critical? If the disk was recorded slow or fast, you'll have
> > > a hard time getting proper frequency response.
> >
> >Playing at the wrong speed affects pitch, but not really frequency
> >response.
>
> Hi, Don,
>
> I think Phillip is on to something here. Since the RIAA curve (and
> many other curves) have breakpoints in them, and if it is used at the
> wrong speed, then the curve breakpoint frequencies don't align with
> the reproduced frequencies and yes, there will be some additional,
> speed-induced errors in the frequency response.
>
> If you're going to re-pitch a recording in software, perhaps this is
> a good reason to apply the curve in software, using a flat preamp for
> the transfer. That way, the curve is applied after the pitch is
> corrected. Now, of course, do we know the precise tuning of the
> original? A=440? Maybe? Maybe not.
>
Well, in most cases the inaccuracy of frequencies created by playback
at a different speed that the one used for the recording shouldn't
have a substantial effect on the accuracy of the playback curve
compared to the recording curve...speeds aren't ususlly that far
"out of whack!" If the "rolloff" is theoretically at 5KHz and the
player is 2% slow, the band from 5KHz to 5100Hz won't be rolled
off...would that even be a halftone?

However, the listener...especially if he/she/it is trying to
play a fixed-pitch instrument (i.e. harmonica) along with the
recording...will notice the pitch inaccuracy...

Steven C. Barr