Silly question!
 

On Sun, 12 Jul 2015 10:25:41 +0100, RJH wrote:


The click removal I can appreciate. But why is it necessary to capture
the audio at 96/24? Isn't 44/16 more than enough for LPs? Then save as
44/16 Flac.

Capturing at the higher rate is important for click removal. The audio
information is pretty much gone by 20kHz, while clicks are still there
at 25 - 30kHz. That makes them a piece of cake to identify, and you
can get rid of them without compromising the higher audio frequencies.

d

Linn Majik
 

On 11/07/2015 12:49, Jim Price wrote:
On 11/07/15 11:55, Dave Plowman (News) wrote:
In article ,
RJH wrote:

I had a http://www.oneforall.co.uk/ a while back, and I'm pretty sure
you can enter codes from their appliance database, straight into the
remote.

That's how the Harmony is meant to work. But you also have to
programme in
what the various buttons do.

I'd have thought it better to have everything work, then give you the
choice of changing what does what - if the defaults ain't to your taste.

That's just what you can do with the better One-For-All remotes. If you
can find a code which will turn the power off on your device, then you
can get the rest of the functions of that device assigned to keys if you
have the patience. They have provided me with the code map for
particular devices when I've asked them, and I have a TV upstairs where
my universal remote can switch directly to a given input, which is a
function the original supplied remote did not have. Also, it doesn't
need a windows computer in order to set it up, which is handy because I
don't have one.


Indeed - I vaguely remember going through something similar. I think it
then feeds back to peer-informed codes. The OPs amp has two 'master'
codes for example.

Bit late now, granted, now he's got a Logitech. I'll dig it out in the
next few days and see if it might suit.

--
Cheers, Rob

Silly question!
 

In article , RJH
wrote:
I'm finding that 96k/24 captures made with the Benchmark ADC show no
audible sign to me that they aren't the LP. And I routinely am able to
remove clicks to make an 'inaudible mend'. For some old LPs that makes
a big difference.


The click removal I can appreciate. But why is it necessary to capture
the audio at 96/24? Isn't 44/16 more than enough for LPs? Then save as
44/16 Flac.

In part its as Don says. having a more detailed representation makes
editing easier to do carefully and minimise any 'damage' caused.

Also it makes it easier to give yourself more 'elbow room' thoughout the
entire process.

e.g. I have the ADC set to clip at about +18dBRIAA. Most LPs won't peak
that high, but *some* do. Having good 24bit range means you don't have to
care that you may be 'wasting' a few bits of theoretical resolution.

Any processing will change the values so risks an increase in the
background 'noise' added by dither. Again, using 24 bit means that is
unlikely to matter.

Then when replaying, you can have more confidence that imperfections of the
precise digital / analog filtering deployed by the ADC and DAC will tend to
be well ultrasonic.

In theory, all ADCs/processing/DACs are perfect - i.e. reach the Shannon /
Nyquist limits. In reality, nope. Having the elbow room helps shove the
imperfections out of earshot. It deoends on the quality of the ADC/DAC of
course. as exampled sadly on the 'Health Check' pages I did a while ago.
Give a fairly clear demo of why some CDs may sound better than others.

Given 1TB drives these days, using flac for stereo audio 96k/24 really
isn't much of a problem in terms of file sizes. So why bother to
downsample? particularly an awkward one like 96k - 44.1k which is hard to
do well. (If I did downsample from 96k I'd go for 48k as its a trivial
ratio to do well.)

That said, I do have some high bitrate Flac files that do sound very
good indeed. To my ear, better than CD. I'm just not sure why,
technically, they may sound better than say CD.

Or better than what the DAC does at 44.1k.


Might there be a way to host samples of tracks recorded using different
techniques and kit, I wonder?

It might be possible for short examples. That would avoid needing a lot of
webspace and copyright problems. Small excerpts would be 'legal' under the
allowances for study purposes, etc.


LP playback for me is more than the sound. And barring a calamity, 40
years of listening to LPs through some pretty arduous storage and care
regimes hasn't affected the sound too much. I'd take your point on
recordings that no longer exist, though.

Afraid I've always found the rituals of LP playback a bit of an annoyance.
Yes, I like the look of a clean LP, and welcome the sleeve, etc. Gives you
the feeling that you do have something worth having. But playing the file
is so much easier, and here sounds as good or better to me.

I can certainly boot up a machine and play the file faster and easier than
I can get the LP playing. And no worries about dust, damage, wear,
accident, etc.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

Linn Majik
 

On 12/07/15 10:48, RJH wrote:
On 11/07/2015 12:49, Jim Price wrote:

That's just what you can do with the better One-For-All remotes. If you
can find a code which will turn the power off on your device, then you
can get the rest of the functions of that device assigned to keys if you
have the patience. They have provided me with the code map for
particular devices when I've asked them, and I have a TV upstairs where
my universal remote can switch directly to a given input, which is a
function the original supplied remote did not have. Also, it doesn't
need a windows computer in order to set it up, which is handy because I
don't have one.


Indeed - I vaguely remember going through something similar. I think it
then feeds back to peer-informed codes. The OPs amp has two 'master'
codes for example.

Bit late now, granted, now he's got a Logitech. I'll dig it out in the
next few days and see if it might suit.

Well, I did suggest the One-For-All and provide the codes in my first
reply :)

--
╔�╦�╦�����╦���╗
â•‘ â•‘ â•‘ â•‘ â•‘
╔�� ║ ║ ║ ║ ║ ╔��
╚���╩�╩�╩�╩�╩�� -- JimP.

Silly question!
 

On 12/07/2015 10:25, RJH wrote:
The click removal I can appreciate. But why is it necessary to capture
the audio at 96/24? Isn't 44/16 more than enough for LPs? Then save as
44/16 Flac.

I capture at 88k/24bit, then clean it up, then downsample.

I don't have to get the record volume just right - I can lose a few
bits, then fix it in the digital domain - and having the extra doesn't
hurt at that point. I capture at 88k because it's easier to downsample
88k to 44k so I can write it to a CD, than it is to downsample from 96k.
OK, in theory you can go 96-44 with no trouble - but I like to make it
easy for the programs.

Andy

Silly question!
 

On Sun, 12 Jul 2015 21:56:47 +0100, Vir Campestris
wrote:

On 12/07/2015 10:25, RJH wrote:
The click removal I can appreciate. But why is it necessary to capture
the audio at 96/24? Isn't 44/16 more than enough for LPs? Then save as
44/16 Flac.

I capture at 88k/24bit, then clean it up, then downsample.

I don't have to get the record volume just right - I can lose a few
bits, then fix it in the digital domain - and having the extra doesn't
hurt at that point. I capture at 88k because it's easier to downsample
88k to 44k so I can write it to a CD, than it is to downsample from 96k.
OK, in theory you can go 96-44 with no trouble - but I like to make it
easy for the programs.

Andy

Downsampling from 88kHz is no easier than from 96kHz. You have to go
through the same process of interpolation, upsampling, lowpass
filtering, and finally decimation. Never try to do it by skipping
alternate samples - that way lies alias distortion from quantization.

And of course every audio ADC uses a massively high sampling rate,
followed by the procedure above to arrive even at 44.1kHz sampling.

d

Silly question!
 

In article , Don Pearce
wrote:
Downsampling from 88kHz is no easier than from 96kHz. You have to go
through the same process of interpolation, upsampling, lowpass
filtering, and finally decimation. Never try to do it by skipping
alternate samples - that way lies alias distortion from quantization.

I'm a bit pun surprised that you wrote that. Makes you look like a
mathematician/theoretician rather than an injuneer. 8-]

The actual real computation of a good 96k - 44.1k conversion does tend to
be far more demanding in terms of number of operations / coefficients / etc
than 88.2 - 44.1k. And I'm not talking about simply discarding, but about
getting at least the same level of quality.

So in theory all you have to do is invoke something like a windowed sinc
convolution and write a nice equation or two on a whiteboard. That works
fine for both. The mathematician can then put the pen down and walk away.
But when it comes to the real number crunching the two cases are very
different for similar quality.

e.g. in a TDA method, a power of two ratio downsample means you only need
one set of coefficients and the clocking is trivial along the arrays. Doing
96 - 44.1 requires rather more effort / complexity for the same output
quality even if you throw the same impulse function at them both. This may
matter both in terms of ensuring you've bugfixed and in terms of CPU
loading or the number of devices on the silicon and the power demand.


And of course every audio ADC uses a massively high sampling rate,
followed by the procedure above to arrive even at 44.1kHz sampling.

Erm, we weren't really talking about the ADC but digital-digital
conversions, probably by running software on a general computing system.
But that doesn't change the above point. And TBH even in hardware like an
ADC or DAC running at a high internal rate, simple integer rations make
good results easier to obtain with less number-bashing.

And of course high rate low-bit tends to risk problems like the ones which
can show up in the 'Health Checks' I did a while ago.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html