Re: [ARSCLIST] ELP Turntable (was historical stylus rake angles)

[George Brock-Nannestad <pattac@xxxxxxxx>]

From: Patent Tactics, George Brock-Nannestad

Jeffrey Kane wrote

> My apologies, I should know to be more specific, especially with you lot. :)
> By noise, I'm referring to pops and clicks seemingly caused by dust, sediment
> and other contaminants. The player seems to be extremely sensitive. Despite
> the noise blanking feature pops and clicks still seem amplified far more than
> a conventional player, to the point of being intrusive. I don't find this to
> be as much of an issue with 78s (perhaps due to the larger groove
> dimensions?), it's primarily an issue with "micro-grooved" material.
>

----- and several others have commented in a similar vein.

Now, the noise (impulse) signal we hear that originates from a groove surface
has been severely processed by a) the preamplifier, b) the amplifier, c) the
output amplifier, and d) the loudspeakers. Any of those components may have
insufficient headroom and/or bandwidth for the task, because a minute surface
imperfection reproduced by a velocity-sensitive system has a huge level and a
very high frequency content - above 30 kHz is quite relevant. This means a
smearing in time of the noise pulse by any uncorrected band limiting, and
that makes it very audible. Michael Gerzon in SEVA's 38 kb mail of yesterday
has a few words on this. So, unless you have a very large gain-bandwidth
product, local feedback rather than global feedback, hence fast overload
recovery, then your noise will be audible, irrespective of stylus origin or
laser origin. Only with a stylus, in addition you have cantilever problems.

And the loudspeaker must be of similar high grade - Quad electrostatics or
Magneplanar (or more recently Bang & Olufsen BeoLab5000 that works on a
different principle, but which is impulse-repsonse corrected). I fully expect
the tests on the ELP that are upcoming (and I gather will be reported by Eric
Jacobs to ARSC) to take the amplifier-loudspeaker chain into consideration.

And if you cannot afford an ELP after having upgraded all the rest: even your
stylus gramophone will sound better for it.

Kind regards,


George