On Wed, 11 Mar 2015 11:39:29 GMT, (Don Pearce) wrote:

On Wed, 11 Mar 2015 11:21:54 +0000 (GMT), "Dave Plowman (News)"
wrote:

In article ,
Sumatriptan wrote:
Good morning experts ;-)

I've been going through my HFN test record. Most of it makes sense but I
don't understand my pink noise results. They show an approximate 10 dB /
decade tilt, which is what I would expect from pink noise. For example,
here's a frequency analysis of a 'perfect' pink noise sample generated
by Audacity.

http://www.nu-ware.com/Misc/Screensh...nk%20Noise.png

Here is the result of the HFN pink noise test using my M55E cartridge.

http://www.nu-ware.com/Misc/Screensh...nk%20Noise.png

However, when I look at test results around the web I see essentially
flat curves from pink noise tests. Like this:

http://www.tnt-audio.com/sorgenti/shure_m97xe_e.html

So, what am I missing?

I'd say it's likely impossible to record perfect pink noise to vinyl.

The peaks you're seeing above 10kHz are likely down to the capacitance of
the connecting leads. If you try a different type, you'll likely see a
different result. Not quite sure of the theory behind this, but it's what
I've experienced with variable reluctance cartridges. Perhaps an expert
would explain it?

Hadn't thought about the vinyl limitations. The bottom end rolloff
probably happened during mastering to stop the cutter ripping the
vinyl in two.

The top end is certainly some sort of resonance - whether mechanical
in the cartridge, or as you say electrical between the cartridge
inductance and the cable capacitance.

d

In fact I've just remembered I did have a look at how a V15 cart
responded to cable capacitance. It's he

http://www.soundthoughts.co.uk/read/cartridge.pdf

It assumes the cartridge to be nominally flat with no capacitive
loading. The peak is at about 10kHz.

d