On Sat, 10 Nov 2007 17:46:45 +0000 (GMT), Jim Lesurf
wrote:

In article , Don Pearce
wrote:

Compare with a sweep of my OC9 in an SME 3009ii arm. Excuse the drawn
line on the curve - it was there to show the effective slope of a flat
response. It doesn't have the multiple glitches that your show.

http://81.174.169.10/odds/dskr/atoc9.gif

I also used the HFN test disc.

Which track(s) of which disc? The one HFN advertise at present?

Slainte,

Jim

The disk is HFN 001, not the "producer's cut".

The track is side 1 track 3, -20dB pink noise L + R. Just realised it
wasn't a sweep, but since I recorded it silent (didn't listen) I
didn't notice that.

d

--
Pearce Consulting
http://www.pearce.uk.com

Don Pearce wrote:
On Sat, 10 Nov 2007 17:46:45 +0000 (GMT), Jim Lesurf
wrote:

In article , Don Pearce
wrote:

Compare with a sweep of my OC9 in an SME 3009ii arm. Excuse the drawn
line on the curve - it was there to show the effective slope of a flat
response. It doesn't have the multiple glitches that your show.
http://81.174.169.10/odds/dskr/atoc9.gif
I also used the HFN test disc.
Which track(s) of which disc? The one HFN advertise at present?

Slainte,

Jim

The disk is HFN 001, not the "producer's cut".

The track is side 1 track 3, -20dB pink noise L + R. Just realised it
wasn't a sweep, but since I recorded it silent (didn't listen) I
didn't notice that.

d


Ah! That'd explain quite a bit. The graph of pink noise is virtually
identical to yours.

I used side 2 track 7 (full range system frequency check) of the HFN
Analogue Test LP, The Producer's Cut.

Rob

In article , Rob
wrote:
Don Pearce wrote:
On Sat, 10 Nov 2007 17:46:45 +0000 (GMT), Jim Lesurf
wrote:

Which track(s) of which disc? The one HFN advertise at present?


The disk is HFN 001, not the "producer's cut".

The track is side 1 track 3, -20dB pink noise L + R. Just realised it
wasn't a sweep, but since I recorded it silent (didn't listen) I
didn't notice that.

OK. That makes me think your results will be reliable. See below... :-)

Ah! That'd explain quite a bit. The graph of pink noise is virtually
identical to yours.

I used side 2 track 7 (full range system frequency check) of the HFN
Analogue Test LP, The Producer's Cut.

I would be wary of that if you want to check the frequency reponse of your
replay system.

When I was doing some measurements a while ago (for an article that should
appear in a couple of months) I also used Side 2 Track 7 of the HFN
"Analogue Test LP. Producer's Cut". It gave results which didn't agree with
what I expected. Nor with similar tests using other discs in the past.

I checked using the noise bands on an old HFS75 test disc. This gave
results almost exactly like those I expected, and as given in the
literature of the cartridge manufacturer (Shure).

I do now have a copy of HFN001, loaned by a friend. Haven't yet checked it
out. But from my experience I would suspect it is more reliable than the
'sweep' on the current "producer's Cut" HFN test disc. Note that the blurb
on the disc says nothing about how flat (or otherwise!) this sweep may be.

So the difference in the results you've just discussed may be due in part
to the use of the 'sweep' on that disc.

Does anyone know of an easily available test LP with a decent set of swept
bands, noise, levels, etc? One that is calibrated and reliable?

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.audiomisc.co.uk/index.html
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html

Jim Lesurf wrote:
In article , Rob
wrote:
Don Pearce wrote:
On Sat, 10 Nov 2007 17:46:45 +0000 (GMT), Jim Lesurf
wrote:

Which track(s) of which disc? The one HFN advertise at present?

The disk is HFN 001, not the "producer's cut".

The track is side 1 track 3, -20dB pink noise L + R. Just realised it
wasn't a sweep, but since I recorded it silent (didn't listen) I
didn't notice that.

OK. That makes me think your results will be reliable. See below... :-)

Ah! That'd explain quite a bit. The graph of pink noise is virtually
identical to yours.

I used side 2 track 7 (full range system frequency check) of the HFN
Analogue Test LP, The Producer's Cut.

I would be wary of that if you want to check the frequency reponse of your
replay system.

When I was doing some measurements a while ago (for an article that should
appear in a couple of months) I also used Side 2 Track 7 of the HFN
"Analogue Test LP. Producer's Cut". It gave results which didn't agree with
what I expected. Nor with similar tests using other discs in the past.

I checked using the noise bands on an old HFS75 test disc. This gave
results almost exactly like those I expected, and as given in the
literature of the cartridge manufacturer (Shure).

I do now have a copy of HFN001, loaned by a friend. Haven't yet checked it
out. But from my experience I would suspect it is more reliable than the
'sweep' on the current "producer's Cut" HFN test disc. Note that the blurb
on the disc says nothing about how flat (or otherwise!) this sweep may be.

So the difference in the results you've just discussed may be due in part
to the use of the 'sweep' on that disc.


OK, thanks. In fact the difference we were discussing never existed - we
were talking about two different things.

I've been able to get consistent (but strange to my untrained brain)
results from effectively the same cartridge and a range of TTs, arms and
preamps.

Does anyone know of an easily available test LP with a decent set of swept
bands, noise, levels, etc? One that is calibrated and reliable?


I've just found 'BBC Stereo Test Disc' (Pye REC 355 Stereo, 1979).
Doesn't say too much about the frequency response/distortion/impedence
tests - on frequency test it says a measuring instrument with a flat
response is needed. The first side (IIRC) is Robert Dougal telling the
listener 'This is my voice from the left hand radiogram loudspeaking
device' and so on. I doubt it's calibrated or reliable but if you'd like
a scan of the sleeve notes, no problem.

Rob

In article , Rob
wrote:
Jim Lesurf wrote:


Does anyone know of an easily available test LP with a decent set of
swept bands, noise, levels, etc? One that is calibrated and reliable?


I've just found 'BBC Stereo Test Disc' (Pye REC 355 Stereo, 1979).
Doesn't say too much about the frequency response/distortion/impedence
tests - on frequency test it says a measuring instrument with a flat
response is needed. The first side (IIRC) is Robert Dougal telling the
listener 'This is my voice from the left hand radiogram loudspeaking
device' and so on. I doubt it's calibrated or reliable but if you'd like
a scan of the sleeve notes, no problem.

No, that's OK. My question is because I'd like to obtain some new test LPs.
Ones with decent sweeps or sets of test tones at various frequencies,
levels, and distances from the center. Do Orthofon sell these? I assume
Shure abandoned doing so many years ago as they seem to have lost interest
in this area.

FWH I was quite dissapointed by the current HFN test LP. Seemed to me to be
a poor selection of tracks. Ended up using my 1975 'HFN75' disc for the
work I did recently. However I suppose the idea with the HFN disc is simply
for the user to check their playing force/bias and check the system is
tracking OK.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.audiomisc.co.uk/index.html
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html