Re: [ARSCLIST] Non-RIAA preamp

[phillip holmes <insuranceman@xxxxxxxxxx>]

If the record is playing at the wrong speed, it should affect frequency 
response because RIAA equalization has the two turnover frequencies 
where bass boost and treble cut starts.  The preamp doesn't know that 
the turntable is running slow or that the spindle hole is not centered.  
Therefore the frequencies being affected by the cut and boost is 
constantly changing (creating these little humps and dips in the 
response).  Now, am I wrong?  I could be.  But it seems like what 
happens when the records aren't reproduced at exactly the right speed.
Phillip

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.
>
>   
> > And many older playback
> > decks ran slow or fast, again making the frequency response and phase
> > wrong. But the absolute worst is off centered pressings that cause a
> > constant change in phase and frequency response. 
> >     
>
> Constant change in pitch and phase.
>
>