NAD 5040 Turntable Help

Archived from groups: rec.audio.high-end (More info?)

Steve wrote:


> Some more info, when playing an LP my speakers throw a good inch and a
> half at a freq. of about 1.5 cps. It just seems that there is some other
> noise comming in that shouldn't be there AT ALL.
>
> Where could this low freq noise be comming from?

1.5 Hz? Probably a resonance, the arm mass vs. stylus compliance.
Occurs when a cartridge with too-compliant stylus is used with an arm
that is too high in mass and is undamped. It can also be exacerbated by
an undamped turntable suspension and a shaky floor, and a phono stage
that lacks a subsonic rolloff, so this 1.5 Hz signal is being amplified
excessively, with the extra gain in the low freqs that comes along with
the RIAA phono equalization. If nothing else, it's a waste of amplifier
power and may cause intermodulation at the woofer cone (this was a
favorite peeve of Paul Klipsch).

Carefully watch the stylus as a record is played. If the arm is
bouncing up and down on it like a Philadelphia pimp's Cadillac Fleetwood
on a potholed street, the arm is too massive for the compliance of the
stylus. You can't easily change the arm, and adding viscous damping
would be difficult. Have the stylus suspension examined, in case its
suspension has gone bad. If it hasn't, you need a different,
lower-compliance cartridge.

-GP