David Looser wrote:
"Peter Larsen" wrote in message
...


I have found it most useful to sample them at 96 kHz 16 bit so as to
save disks space, I don't see any logical reason in wasting it for
writting 16 binary ones for each sample, but I want a good sharp and
undistorted clicks in case automated click removal is relevant.
Mostly I just take the big ones out with fix single click
functionality,

Does anyone remember the Garrad "Music Recovery Module"? It was
designed to remove the big clicks in real time by briefly shunting
the audio with a light-dependent resistor when a click was detected.
Click detection was based on the idea that clicks were of large
amplitude, had a fast rise-time and had a significant out-of-phase
component. It actually worked quite well, but no match for a software
solution.

That would freak out on modern hip-hop stuff that has surface noise/clicks
as part of the 'music' !

FWIW I'm looking at my old 301/SME/SME spinning away, right now .

geoff

Eiron wrote:
David Looser wrote:
worked quite well, but no match for a
software solution.

Scratch filters such as that in Goldwave are excellent; there is no
reason not to use them on a whole album. I tried subtracting the
'cleaned' version from the 'raw' one and was left with just the
clicks and scratches on a background of perfect silence, thus showing
that the filter didn't remove any music.

Waves X-Click/Noise/Crackle allow you to listen to the output audio, or the
'removed' audio realtime.

geoff

"geoff" wrote in message
...
David Looser wrote:
"Peter Larsen" wrote in message
...


I have found it most useful to sample them at 96 kHz 16 bit so as to
save disks space, I don't see any logical reason in wasting it for
writting 16 binary ones for each sample, but I want a good sharp and
undistorted clicks in case automated click removal is relevant.
Mostly I just take the big ones out with fix single click
functionality,

Does anyone remember the Garrad "Music Recovery Module"? It was
designed to remove the big clicks in real time by briefly shunting
the audio with a light-dependent resistor when a click was detected.
Click detection was based on the idea that clicks were of large
amplitude, had a fast rise-time and had a significant out-of-phase
component. It actually worked quite well, but no match for a software
solution.

That would freak out on modern hip-hop stuff that has surface noise/clicks
as part of the 'music' !

It could be switched to "bypass", in which case it became merely a
high-quality RIAA pre-amp.

David.

"geoff" wrote in message
...
Peter Larsen wrote:
Steven Sullivan wrote:


The peak signal when recording vinyl comes frm the clicks, usually 6
dB higher than the signal for the large ones. Grammophone records and
quality playback of them can provide a very high quality sound IF and
only IF all links are good.

I have found it most useful to sample them at 96 kHz 16 bit so as to
save disks space, I don't see any logical reason in wasting it for
writting 16 binary ones for each sample, but I want a good sharp and
undistorted clicks in case automated click removal is relevant.
Mostly I just take the big ones out with fix single click

Record at 24 bits, then once you've got rid of your clicks, then you can
raise the overall level with less degradation.

Why 96/16 rather than 44k1/24 ? I don't follow that logic. The highest
freq recorded on most LPs was around 15KHz, apart from clicks of course...


I'm not sure I follow yours. Whilst the highest *recorded" frequency was
around 15kHz, the click spectrum would go much higher than that so
preserving the fast risetime of the clicks would be of value to automatic
click detection software. On the other hand the S/N ratio of no better than
70dB requires only a 13-bit ADC, leaving a margin of 3 bits (18dB) for click
headroom/ post digitising amplification even when using a 16-bit converter.
And it doesn't matter if high-amplitude clicks are clipped, as long as the
rise-time is preserved.

I would be astonished if anyone could tell the difference between an
original 24-bit digitisation and a 16-bit one when digitising vinyl.

In the old days of 405-line TV the (AM) sound channel would have a simple
impulse interference reduction limiter fitted. This worked on the fact that
the impulse would have a far faster rise-time than any audio content. For
this reason the band-width of the sound IF channel was kept far wider than
need for the audio, around 100kHz.


David.

David Looser wrote:

What millenium are you living in guys, look at the waveform, does it
hit 0 dB FS?

How do you look at an analogue waveform?,

Surely the screen image of the audio editor package is good enough.

we are talking about
setting the analogue level into the ADC.

And?

You can, of course, do a transfer, look at the resulting digital
waveform, and then re-do it if the levels are way off, but generally
it's easier to get it more or less correct the first time.

Correct transfer means that the loudest click is not clipped, you only need
to make that adjustment once.

David.


Kind regards

Peter Larsen

"David Looser" wrote in
message
"Peter Larsen" wrote in message
...
David Looser wrote:

Not necessarily ideal, due to the possibility of
intersample peaks. It's advisable to
record with peak samples a dB or three shy of 0 dBFS,
unless you have accurate peak monitors
that show you what the *output* level is.

That's really a measurement problem. If you actually
know exactly what the "peak of peaks" is, that can be
just shy of 0dBFS. I agree in practice a 3dB or so
margin between *apparent* peak and 0dBFS is advisable.

What millenium are you living in guys, look at the
waveform, does it hit 0 dB FS?


How do you look at an analogue waveform?, we are talking
about setting the analogue level into the ADC.

You can, of course, do a transfer, look at the resulting
digital waveform, and then re-do it if the levels are way
off, but generally it's easier to get it more or less
correct the first time.

Most audio capture software has a real time display.

I set levels using a trackability test track. If the cartridge is
mistracking, tain't no need for that much more headroom in the preamp!

Eiron wrote:

Scratch filters such as that in Goldwave are excellent; there is no
reason not to use them on a whole album. I tried subtracting the
'cleaned' version from the 'raw' one and was left with just the
clicks and scratches on a background of perfect silence, thus showing
that the filter didn't remove any music.

Take a known good recording with high quality transients, say a chamber
music recording made with DPA 4006 mikes. Pass it through a declicker,
notice the number of reported "fixed clicks". End of story, except that
there is incredibly poor audio around that will become less offensive via
good automated declick.


Kind regards

Peter Larsen

In article , Arny
Krueger


I set levels using a trackability test track. If the cartridge is
mistracking, tain't no need for that much more headroom in the preamp!

That might need to be interpreted with some care, however. The level which
causes mistracking may vary with frequency, distance from the LP center of
rotation, and may also be different for vertical or horizontal
displacements. Most of the domestic test LPs seem to use test bands with
frequencies of 300 - 400 Hz which isn't necessarily a good guide to signals
with significant content at other frequencies.

Alas, since in recent years both manufacturers of cartridges and magazine
reviews seem to have abandoned analysing the tracking ability of a
cartridge in much detail it is difficult to say more with any precision.
Shure still seem to publish tracking data at 1kHz and 10kHz, but most other
makers seem to give no info on such details. IIRC Shure also tended to use
a 45rpm disc for their own HF tracking tests, which would give better
results than 33rpm.

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

"Peter Larsen" wrote in message
...
David Looser wrote:

What millenium are you living in guys, look at the waveform, does it
hit 0 dB FS?

How do you look at an analogue waveform?,

Surely the screen image of the audio editor package is good enough.

But you don't get to see that until *after* you've made the recording!!!

we are talking about
setting the analogue level into the ADC.

And?

BEFORE you make the recording (so you haven't got a screen image from the
audio editing package to look at yet!)

You can, of course, do a transfer, look at the resulting digital
waveform, and then re-do it if the levels are way off, but generally
it's easier to get it more or less correct the first time.

Correct transfer means that the loudest click is not clipped, you only
need to make that adjustment once.

Yes of course, did I say anything different?

David.

"Arny Krueger" wrote in message
. ..
"David Looser" wrote in
message
"Peter Larsen" wrote in message
...
David Looser wrote:

Not necessarily ideal, due to the possibility of
intersample peaks. It's advisable to
record with peak samples a dB or three shy of 0 dBFS,
unless you have accurate peak monitors
that show you what the *output* level is.

That's really a measurement problem. If you actually
know exactly what the "peak of peaks" is, that can be
just shy of 0dBFS. I agree in practice a 3dB or so
margin between *apparent* peak and 0dBFS is advisable.

What millenium are you living in guys, look at the
waveform, does it hit 0 dB FS?


How do you look at an analogue waveform?, we are talking
about setting the analogue level into the ADC.

You can, of course, do a transfer, look at the resulting
digital waveform, and then re-do it if the levels are way
off, but generally it's easier to get it more or less
correct the first time.

Most audio capture software has a real time display.

But it's not predictive. If it indicates clipping you can only go back and
start again.

I set levels using a trackability test track. If the cartridge is
mistracking, tain't no need for that much more headroom in the preamp!

Fine, but bearing in mind that there are large variations in maximim level
from LP to LP you will probably need to apply amplification to the digital
file on some (most?) of the recordings later.

David.