Sound card for recording
Tony Houghton
vinyl collection to digital etc. I'm wondering whether I should use a
better sound card than the onboard sound.
I know one of the regulars here occasionally posts about an almost
universal design flaw on sound cards where the input circuitry clips
well below the potential ability of the A/D convertor or something. I
did try recording from vinyl via a T/T preamp to a basic onboard sound
card a few years ago. The preamp has no gain control and ISTR the result
did sound slightly distorted as if clipped.
I've got one of those old Santa Cruz/Sonic Fury cards lying around,
which were reckoned to be pretty good in their time. Would it be worth
installing that for recording? I found an old review:
Audio Converters: Dual AC-97 2.1 audio codecs with hardware full-duplex
for simultaneous record and playback and up to 48 kHz sample rates.
18-bit A/D converters for high-resolution recording. 20-bit D/A
converters for high-resolution playback of up to 6 independent streams.
Alternatively I could probably borrow my friend's EMI external USB sound
adapter which he bought especially for semi-professional recording a few
years back. Significantly better still?
--
TH * http://www.realh.co.uk
Rob Morley
Tony Houghton <h...@realh.co.uk> wrote:
> I know one of the regulars here occasionally posts about an almost
> universal design flaw on sound cards where the input circuitry clips
> well below the potential ability of the A/D convertor or something. I
> did try recording from vinyl via a T/T preamp to a basic onboard sound
^^^
???
Trev
"Tony Houghton" <h...@realh.co.uk> wrote in message
news:slrnhhqi...@realh.co.uk...
Beware its not just a pre amp that's needed to amplified the signal but it
also needs to be corrected from the Riaa
curves to a flat curve for the audio card. The upper frequencies are boosted
at the point of recording Vinyl to make the needle produce a stronger signal
Tony Houghton
Trev <tre...@hotmail.com> wrote:
> "Tony Houghton" <h...@realh.co.uk> wrote in message
> news:slrnhhqi...@realh.co.uk...
>> did try recording from vinyl via a T/T preamp to a basic onboard sound
In answer to Rob's question, T/T = turntable.
> Beware its not just a pre amp that's needed to amplified the signal
> but it also needs to be corrected from the Riaa curves to a flat curve
> for the audio card. The upper frequencies are boosted at the point of
> recording Vinyl to make the needle produce a stronger signal
It's OK, it's a preamp especially for turntables. I forgot about the
RIAA acronym, but now you've mentioned it I do remember reading about it
at some point.
Johnny B Good
from Tony Houghton <h...@realh.co.uk> contains these words:
> I'd like to make some recordings, maybe transferring some gems from my
> vinyl collection to digital etc. I'm wondering whether I should use a
> better sound card than the onboard sound.
> I know one of the regulars here occasionally posts about an almost
> universal design flaw on sound cards where the input circuitry clips
> well below the potential ability of the A/D convertor or something.
That might have been me. It seems that _all_ the PCI soundcard
manufacturers "To A Man" (including the on-board sound used in
motherboards - all effectively connected via the PCI bus) just simply
used the "reference" design as issued by the soundchip manufacturers
without considering the implications of the reduced 5v unipolar bias
rail on the clipping limits of the line-in buffer amp.
The chip had a 'jumper link' option to desensitise the ADC input by 6db
(not a problem with a buffer amp powered by a 12v rail) which, rather
unfortunately, had been shown on the reference circuit as 'enabled'.[1]
> I did try recording from vinyl via a T/T preamp to a basic onboard sound
> card a few years ago. The preamp has no gain control and ISTR the result
> did sound slightly distorted as if clipped.
How severe this effect sounds rather depends on how much headroom
you've allowed. The input clipping level corresponds to about -4db FSD.
If you were aiming to set the peaks to about 3db (thinking you'd still
have a 3db margin), it would only be obvious during the loudest
passages.
Professional kit seems rather overkill just to digitise a vynil
collection unless you can get hold of second user kit 'for a song'. If
you have the space, a cheaper alternative would be to use an older PC
that still has at least one ISA slot and fit a SB16 or AWE32 or AWE64
soundcard.
The AWE64 Gold has line input clip level around the +14db mark which
closely matches the line out clipping level of the RIAA pre-amp I built
into my record deck ;-) . The AWE32's clip level is about 3 or 4 db down
(similar to the SB16, afaicr) on this, but still well above the ADC
input clipping level.
The latching clip level indicators in Cool Edit Pro can usefully
indicate whether your initial attempt to digitise an analogue source had
produced FSD values which you can then home in on to ascertain whether
they were significant enough to warrant a second attempt.
Unfortunately, PCI soundcards totally ruin this feature, requiring you
to deliberately under-record by a good 10db and then check that
normalising to FSD required no less than a 5db boost to achieve (less
than 4db implying the peaks had been clipped before they hit the DAC
stage).
> I've got one of those old Santa Cruz/Sonic Fury cards lying around,
> which were reckoned to be pretty good in their time. Would it be worth
> installing that for recording? I found an old review:
If that's a PCI card, experiment and check whether it bucks the trend
(unlikely, but still worth checking).
> Audio Converters: Dual AC-97 2.1 audio codecs with hardware full-duplex
> for simultaneous record and playback and up to 48 kHz sample rates.
> 18-bit A/D converters for high-resolution recording. 20-bit D/A
> converters for high-resolution playback of up to 6 independent streams.
All that "digital bling" will be for naught if the line in buffer clips
4db below the ADC's line in level.
> Alternatively I could probably borrow my friend's EMI external USB sound
> adapter which he bought especially for semi-professional recording a few
> years back. Significantly better still?
Maybe, assuming it really _is_ made to a 'semi-professional' standard.
I suspect it might be even more prone to line input clipping if it is
line powered from the USB socket on account of the reduced voltage
(typically 5v minus the reverse polarity protection diode volt drop of
0.3 or 0.7 volts, depending on the diode type used).
If the unit has its own seperate power source, this shouldn't be an
issue if the buffer amp is powered from a sufficently high enough
voltage to avoid clipping below the ADC's line in clipping level.
[1] I think this was achieved by programming the ADC reference voltage
from 2.56v to 5.12v (effectively, a peak to peak limit of the analogue
input voltage range). Reducing the reference even further just
'amplifies' the analogue input noise even further.
The choice of 5.12v was obviously a noise issue based decision without
regard to the effect of using a 5 volt rail in place of the 12v rail
used by the older ISA based designs (which could even have had the
benefit of a dual rail supply <+/-12v>).
Given a sensible choice of ADC reference voltage, even a decent USB
dongle style of converter could do better than the vast majority of PCI
based soundcard designs in this regard just as long as you have a means
of attenuating the line in level coming from the analogue source.
--
Regards, John.
Please remove the "ohggcyht" before replying.
The address has been munged to reject Spam-bots.
Bernard Peek
<jcs.comp...@plugzetnet.co.uk> writes
> That might have been me. It seems that _all_ the PCI soundcard
>manufacturers "To A Man" (including the on-board sound used in
>motherboards - all effectively connected via the PCI bus) just simply
>used the "reference" design as issued by the soundchip manufacturers
>without considering the implications of the reduced 5v unipolar bias
>rail on the clipping limits of the line-in buffer amp.
There's a Toshiba external device that uses both +5 and +12 supplies.
Morgan were flogging them for a tenner plus VAT. I haven't noticed any
clipping with mine.
--
Bernard Peek
Tony Houghton
Bernard Peek <b...@shrdlu.com> wrote:
They don't seem to be selling them any more. There's one on eBay I could
go for though. It's difficult to tell exactly what it's for from the
blurb. Is it like a KVM that does audio instead of video (recording as
well as playback?) and it has its own audio processor? It looks like
it's officially only compatible with W2K and XP, although it's
apparently based on a Creative device, so there is a chance it'll work
with Linux. Have you got any utilities or a Linux Live CD which would
tell you what makes it tick?
Mike Tomlinson
<nos...@ntlworld.com> writes
> ???
I had to think too. :o) Turntable.
--
(\__/)
(='.'=) Bunny says Windows 7 is Vi$ta reloaded.
(")_(") http://imgs.xkcd.com/comics/windows_7.png
Mike Tomlinson
writes
>I'd like to make some recordings, maybe transferring some gems from my
>vinyl collection to digital etc.
How about one of those Ion USB turntables? About 75 quid. They have
been available for a while.
The Register reviewed it:
http://www.reghardware.co.uk/2007/05/02/review_ion_usb_turntable/
seems to be available for anything from 50 to 100 quid.
Caveat: I have not used it.
Trev
http://www.amazon.co.uk/Terratec-Aureon-5-1-USB-MKII/dp/B000KYALCI
There is also a Trust Model Similar May even be the same
Adrian C
>> go for though. It's difficult to tell exactly what it's for from the
>> blurb. Is it like a KVM that does audio instead of video (recording as
>> well as playback?) and it has its own audio processor? It looks like
>> it's officially only compatible with W2K and XP, although it's
>> apparently based on a Creative device, so there is a chance it'll work
>> with Linux. Have you got any utilities or a Linux Live CD which would
>> tell you what makes it tick?
>>
>> --
>> TH * http://www.realh.co.uk
>
> http://www.amazon.co.uk/Terratec-Aureon-5-1-USB-MKII/dp/B000KYALCI
>
> There is also a Trust Model Similar May even be the same
Or Behringer's UFO202
http://www.behringer.com/EN/Products/UFO202.aspx
http://www.amazon.co.uk/Behringer-U-Phono-USB-Audio-Interface/dp/B002GHBYZ0
OTOH My trick is to use a decent Sony MiniDisc home recording deck as an
Analogue to Digital Converter (by placing the unit into record
monitoring mode) then feeding it's S/PDIF output to a computer soundcard
digital input.
--
Adrian C
Multithreaded
wrote:
> http://www.reghardware.co.uk/2007/05/02/review_ion_usb_turntable/
>
>seems to be available for anything from 50 to 100 quid.
>
>Caveat: I have not used it.
I imagine someone who cares an inch about quality will just laugh at
those USB monstrosities. To get reasonable sound, you still have to
spend hundreds, if not more, on a dedicated turntable, tonearm, and
quality cartridge [1]. Then one needs a proper phono amp that can give
low noise and cope with the tiny signal that a moving coil cartridge
will output.
Only now can we consider the analogue to digital conversion and
therefore the soundcard. I do a lot of vinyl transfers for friends, as
well as DAT, MiniDisc and cassette tape. I just use my trusty old
Audigy 4 Pro card, but my hearing is now so bad that I have to rely on
others to reassure me that my transfers are indeed very good with no
digital nasties and excess noise; see other thread.
You should, I expect, be able to get a good semi-pro card that does
all my old card can do, and more, and be in PCI-E 1X form, or maybe
Firewire. Most I've seen are USB2, which a sound recordist friend of
mine didn't like for some reason; I had to hunt around for a PCI
solution for the awkward bugger. I dunno, I don't keep up with sound
things because I no longer enjoy sound; it just depresses me.
It's the old hi-fi adage: garbage in, garbage out. You need to get the
source right before you can even think of all the details about
soundcards, etc. I trust that the OP has done this; not sure, though,
as I haven't reread his post as perhaps I should have.
[1] My kit is mostly old but good, still: Roxanne Xerxes turntable and
Rega RB200 tonearm (�450 secondhand, back in 1990!), fineline moving
coil cartridge (�250 in 1997), and phono stage by Rotel (�150 in 2001)
- yes, I know, this unit lacks snob value, but when I got it my
hearing was much better and it sounded well enough on critical
auditioning.
(I wish I could condense my posts more.)
--
Multithreaded.
Tony Houghton
Multithreaded <m...@privacy.net> wrote:
> On Tue, 8 Dec 2009 08:27:46 +0000, Mike Tomlinson <mi...@jasper.org.uk>
> wrote:
>
>> http://www.reghardware.co.uk/2007/05/02/review_ion_usb_turntable/
>>
>>seems to be available for anything from 50 to 100 quid.
>>
>>Caveat: I have not used it.
The trouble is, I might want to do one or more tapes too (although IMO
that's really scraping the barrel in terms of quality).
And I'm not really interested in spending more than a tenner, seeing as
I can borrow my friend's EMI.
> I imagine someone who cares an inch about quality will just laugh at
> those USB monstrosities. To get reasonable sound, you still have to
> spend hundreds, if not more, on a dedicated turntable, tonearm, and
> quality cartridge [1]. Then one needs a proper phono amp that can give
> low noise and cope with the tiny signal that a moving coil cartridge
> will output.
I'm not that fussy, but distortion from clipping tends to be much more
obvious than using a mediocre turntable. Mine's only a cheapo "Eclipse"
from Richer Sounds, but I suspect its cartridge etc is still a bit
better than one of those USB things.
> Only now can we consider the analogue to digital conversion and
> therefore the soundcard. I do a lot of vinyl transfers for friends, as
> well as DAT, MiniDisc and cassette tape. I just use my trusty old
> Audigy 4 Pro card, but my hearing is now so bad that I have to rely on
> others to reassure me that my transfers are indeed very good with no
> digital nasties and excess noise; see other thread.
>
> You should, I expect, be able to get a good semi-pro card that does
> all my old card can do, and more, and be in PCI-E 1X form, or maybe
> Firewire. Most I've seen are USB2, which a sound recordist friend of
> mine didn't like for some reason; I had to hunt around for a PCI
> solution for the awkward bugger. I dunno, I don't keep up with sound
> things because I no longer enjoy sound; it just depresses me.
>
> It's the old hi-fi adage: garbage in, garbage out. You need to get the
> source right before you can even think of all the details about
> soundcards, etc. I trust that the OP has done this; not sure, though,
> as I haven't reread his post as perhaps I should have.
>
> [1] My kit is mostly old but good, still: Roxanne Xerxes turntable and
> Rega RB200 tonearm (£450 secondhand, back in 1990!), fineline moving
> coil cartridge (£250 in 1997), and phono stage by Rotel (£150 in 2001)
> - yes, I know, this unit lacks snob value, but when I got it my
> hearing was much better and it sounded well enough on critical
> auditioning.
I used to know someone who had a "Rock" turntable which cost over a
grand in the 80s. Typical British engineering: the ultimate in audio
quality, but the lid didn't fit and the lifter arm didn't lift the
needle high enough to clear the surface of a record.
Adrian C
> I used to know someone who had a "Rock" turntable which cost over a
> grand in the 80s. Typical British engineering: the ultimate in audio
> quality, but the lid didn't fit and the lifter arm didn't lift the
> needle high enough to clear the surface of a record.
That sounds like he had the wrong cartridge mounted on the arm.
--
Adrian C
Rob
"Adrian C" <em...@here.invalid> wrote in message
news:7o73joF...@mid.individual.net...
Which was very common, as often when you needed a new stylus
you found they no longer made them and had to buy a new cartridge..
Now we buy new printers as replacement ink cartridges are the same
price <sigh>. Notebooks will be next, I guess - fully integrated with
no removable/replacable parts - stops working and you just get
another, as all your work will be in an internet 'cloud', somewhere
(you hope).
--
Rob
Multithreaded
wrote:
>I used to know someone who had a "Rock" turntable which cost over a
>grand in the 80s. Typical British engineering: the ultimate in audio
>quality, but the lid didn't fit and the lifter arm didn't lift the
>needle high enough to clear the surface of a record.
A friend of mine is thinking of selling his Rock - a superb piece of
kit that I wanted back in the 80s myself. My Xerxes is as good,
without that troubling outrigger arrangement. Pity I can no longer
hear the prodigious bass both it and my large 80s speakers produce.
Ho, hum. Still, others can enjoy the quality of my digital transfers,
so I still keep all my audio gear, including the old Audigy 4 Pro PCI
with breakout box. I'm probably the only person in the world who can
still use DAT and has a nice rack-mounted deck connected to a special
D to A box, amplifier and the soundcard.
--
Multithreaded.
BigH2K
"Multithreaded" <m...@privacy.net> wrote in message
news:2p6th5tf1k802r4ej...@4ax.com...
I sold a Linn Sondek LP12, guy came to look at it and looked aghast that it
didn't play singles. Kinda glad he didn't buy it.
Trev
"BigH2K" <bigh...@TAKEITAWAYblueyonder.co.uk> wrote in message
news:8_yTm.13390$Ym4....@text.news.virginmedia.com...
Singles It was the lack of auto change that p...ed him Off
Les Matthew
>
> I'm not that fussy, but distortion from clipping tends to be much more
> obvious than using a mediocre turntable. Mine's only a cheapo "Eclipse"
> from Richer Sounds, but I suspect its cartridge etc is still a bit
> better than one of those USB things.
>
If you can use a soldering iron you could knock together a simple
resistive pad between the amp output and the soundcards line input.
http://www.nu9n.com/tpad-calculator.html
Probably best to use quality metal-oxide resistors.
les...
Michael Chare
Try uk.rec.audio
--
Michael Chare
Jim Lesurf
Chare
<Munders...@chareDOTorg.uk> wrote:
> "Tony Houghton" <h...@realh.co.uk> wrote in message
> news:slrnhhqi...@realh.co.uk...
> > I'd like to make some recordings, maybe transferring some gems from my
> > vinyl collection to digital etc. I'm wondering whether I should use a
> > better sound card than the onboard sound.
> Try uk.rec.audio
Tony can perhaps guess what my response will be from reading already what
I've written elsewhere. However my basic preference is to use an audio
recorder that is not connected to a computer during recording.
This avoids any problems caused by the computer not being able to collect
samples correctly, interference, hum loops, etc, etc.
I've tended to use CD Audio recorders like the Pioneer PDR-509. But am
currently looking at buying a Tascam HD P2. Something like the 509 is quite
cheap, but limited to CDDA (16bit / 44.1ksamples/sec). Whereas the Tascam
goes up to 192ksample sec and 24 bit. But is more expensive. :-) But
there are a number of other audio recorders around.
This means I use the recorder just as you might have used an older cassette
or reel-to-reel as part of the hifi system with no computer attached. Then
carry the recordings on CD to the computer for editing and final writing to
CDDA, or use from a server as you prefer.
For the modern 'solid state' recorders, you'd obvious use either a USB
(or firewire) link or carry the memory card instead of a CD for the
transfer. Treat that as a separate operation to the actual recording
process.
I'm personally wary of using a 'soundcard' as it means a risk of the
computer disturbing making best-quality recordings for various reasons.
However despite this I'd agree that with the better soundcards and a
carefully setup system that approach works well. But I would not use any of
the internal 'soundcards' on any of the computers I have for recording
analogue sources as the results would be poorer than a stand-alone CD Audio
recorder.
Slainte,
Jim
--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scots_Guide/intro/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html
Arny Krueger
message news:tcydnQPDw4VH1L3W...@pipex.net
> "Tony Houghton" <h...@realh.co.uk> wrote in message
> news:slrnhhqi...@realh.co.uk...
>> I'd like to make some recordings, maybe transferring
>> some gems from my vinyl collection to digital etc. I'm
>> wondering whether I should use a better sound card than
>> the onboard sound.
>> I know one of the regulars here occasionally posts about
>> an almost universal design flaw on sound cards where the
>> input circuitry clips well below the potential ability
>> of the A/D converter or something. I did try recording
>> from vinyl via a T/T preamp to a basic onboard sound
>> card a few years ago. The preamp has no gain control and
>> ISTR the result did sound slightly distorted as if
>> clipped.
That's a stupid problem that was created by badly engineered products. It is
a situation that is easy enough to address with a simple attenuator.
>> I've got one of those old Santa Cruz/Sonic Fury cards
>> lying around, which were reckoned to be pretty good in
>> their time. Would it be worth installing that for
>> recording? I found an old review:
If it still works and if you can find appropriate drivers for it, yes.
>> Audio Converters: Dual AC-97 2.1 audio codecs with
>> hardware full-duplex for simultaneous record and
>> playback and up to 48 kHz sample rates. 18-bit A/D
>> converters for high-resolution recording. 20-bit D/A
>> converters for high-resolution playback of up to 6
>> independent streams.
>> Alternatively I could probably borrow my friend's EMI
>> external USB sound adapter which he bought especially
>> for semi-professional recording a few years back.
>> Significantly better still?
Whatever works.
Because of the LP format's inherent technical failings, digitizing LPs is
not all that challenging of a task for even an one of those on-board audio
interfaces that comes with most motherboards.
Jim Lesurf
Krueger
<ar...@hotpop.com> wrote:
> Because of the LP format's inherent technical failings, digitizing LPs
> is not all that challenging of a task for even an one of those on-board
> audio interfaces that comes with most motherboards.
In principle it is slightly complicated because of the possibility of
unpredictably high peaks. But in practice this doesn't seem a problem in my
experience and 16bit samples should be fine if you allow for enough
headroom when setting the gain.
Don Pearce
<no...@audiomisc.co.uk> wrote:
>In article <BtOdnf1Sy__Ib73W...@giganews.com>, Arny
>Krueger
><ar...@hotpop.com> wrote:
>
>
>> Because of the LP format's inherent technical failings, digitizing LPs
>> is not all that challenging of a task for even an one of those on-board
>> audio interfaces that comes with most motherboards.
>
>In principle it is slightly complicated because of the possibility of
>unpredictably high peaks. But in practice this doesn't seem a problem in my
>experience and 16bit samples should be fine if you allow for enough
>headroom when setting the gain.
>
The unexpectedly high peaks are invariably ticks and scratches, and it
really doesn't matter if they overload - they need removing anyway.
d
Arny Krueger
news:4b20f7f9....@news.eternal-september.org
That agrees with my experience. The LP format has a serious problem with
dynamic range, if you define dynamic range as the difference between the
noise floor and the largest relatively undistorted signal related to music
or speech.
If you define dynamic range as the difference between the noise floor and
the largest instantaneous value, no matter how irrelevant to the music or
distorted, then the LP format might have less deficient dynamic range.
We've been in a similar place around here just lately. People have lately
gone on record as demanding sufficient headroom to play back fairly
improbable but rarely observed signals whose samples are all less than FS
but in combination can trick a reconstruction filter into creating an analog
signal that significantly exceeds FS.
I'm not buying either situation as being one that needs to be pandered to.
Dave Plowman (News)
But if you overload the analogue section with a tick etc isn't there a
chance it will effect the prog material immediately afterwards?
--
*Ever stop to think and forget to start again?
Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.
Arny Krueger
message news:50c7868...@davenoise.co.uk
> In article
> <4b20f7f9....@news.eternal-september.org>, Don
> Pearce <sp...@spam.com> wrote:
>> On Thu, 10 Dec 2009 13:24:53 +0000 (GMT), Jim Lesurf
>> <no...@audiomisc.co.uk> wrote:
>
>>> In article
>>> <BtOdnf1Sy__Ib73W...@giganews.com>, Arny
>>> Krueger <ar...@hotpop.com> wrote:
>>>
>>>
>>>> Because of the LP format's inherent technical
>>>> failings, digitizing LPs is not all that challenging
>>>> of a task for even an one of those on-board audio
>>>> interfaces that comes with most motherboards.
>>>
>>> In principle it is slightly complicated because of the
>>> possibility of unpredictably high peaks. But in
>>> practice this doesn't seem a problem in my experience
>>> and 16bit samples should be fine if you allow for
>>> enough headroom when setting the gain.
>>>
>
>> The unexpectedly high peaks are invariably ticks and
>> scratches, and it really doesn't matter if they overload
>> - they need removing anyway.
>
> But if you overload the analogue section with a tick etc
> isn't there a chance it will effect the prog material
> immediately afterwards?
There's a chance the sky will fall. How many sky supports do you keep on
hand? ;-)
In general, modern gear recovers from overloads pretty fast.
If you've got an exceptional case, you can determine that pretty quickly by
looking at the digitized file.
Jim Lesurf
Krueger
<ar...@hotpop.com> wrote:
> We've been in a similar place around here just lately. People have
> lately gone on record as demanding sufficient headroom to play back
> fairly improbable but rarely observed signals whose samples are all
> less than FS but in combination can trick a reconstruction filter into
> creating an analog signal that significantly exceeds FS.
The distinction between that and clicks on an LP is that there is no need
to 'trick' the reconstruction filter and nor does it require the disc to be
physically damaged as in the case of 'clicks' from an LP. The excursions
above 0dBFS arise because the recorded waveforms include them. They are
part of the recorded waveform, not a 'trick' or the result of physical
damage.
So the word 'trick' in this context is misleading and inappropriate, and
the LP and CD cases are not similar in cause. One behaviour arises due to
physical damage and makes the required waveform unrecoverable. The other
can be a result of the required waveform defined by the series of samples
recorded on a correctly produced and physically undamaged disc. The
required waveform may still be defined by the series of samples even if a
given DAC can't cope with reproducing that.
The behaviour (requirements for some peaks above 0dBFS) arises as a
consequence of the Sampling Theorem and basic Information Theory. The
series of samples correctly define the waveform to be reconstructed, as per
the Sampling Theorem. Although some test waveforms show extreme examples
of this, required excursions above 0dBFS can occur for commercial
recordings of music. This is not due to any damage equivalent to an LP
being scratched, but a part of the data on the CD. if you check some
pop/rock CDs you can probably find examples without trying very hard.
> I'm not buying either situation as being one that needs to be pandered
> to.
The main way I "don't buy it" is to avoid buying rock/pop CDs that have
been affected. :-) Alas, you may not know until you have one of the CDs.
So I (and I assume many others) do have CDs where the provided samples
require the reconstructed waveform to exceed 0dBFS between some samples.
What is then unclear is what individual CD players make of this when they
try to reconstruct the waveforms from the data.
Since this is being xposted to a group I don't normally read it may be
helpful for readers there if I give a couple of URLs that examine these
matters in case they haven't encountered this issue previously.
http://www.audiomisc.co.uk/HFN/ClippingOnCD/clipping.html
Shows some examples of one way this can occur with real commercial CDs
http://www.audiomisc.co.uk/HFN/OverTheTop/OTT.html
Examines the effect in detail. Examples show around +2dBFS for commercial
CD, and then an extreme case test waveform.
The important points here are:
1) That the effect examined on CD arises a consequence of using sampled
data. So is an aspect of digital information methods for purposes like
recording audio waveforms.
2) That it can arise as a result of what was recorded, not because of a
situation like an LP being scratched.
3) If the DAC and reconstruction filter are correctly designed they would
reproduce the defined waveform correctly, including the parts above 0dBFS,
whereas a scratched LP would be reproducing the effects of damage.
Note also that this has been discussed in AES papers, etc. And I know that
the BBC (sound radio) people tend to keep down the max sample levels on R3,
etc for similar reasons.
FWIW I'd agree that this *should* be a non-issue in practice, *if* CD
makers ensured they kept down the recorded sample levels to avoid
intersample peaks above 0dBFS and/or if DAC makers ensured they played
waveforms above 0dBFS without distortion. However I'm far from sure that
both these provisos are universal. Certainly I know of both CDs and DACs
that fail to meet these conditions.
Given the large dynamic range of 16bit CD it would be easy for pop/rock to
avoid peaks above 0dBFS. But alas the pop industry obsession with
'loudness' seems to drive them to the maximum they can manage.
Don Pearce
<da...@davenoise.co.uk> wrote:
>In article <4b20f7f9....@news.eternal-september.org>,
> Don Pearce <sp...@spam.com> wrote:
>> On Thu, 10 Dec 2009 13:24:53 +0000 (GMT), Jim Lesurf
>> <no...@audiomisc.co.uk> wrote:
>
>> >In article <BtOdnf1Sy__Ib73W...@giganews.com>, Arny
>> >Krueger
>> ><ar...@hotpop.com> wrote:
>> >
>> >
>> >> Because of the LP format's inherent technical failings, digitizing
>> >> LPs is not all that challenging of a task for even an one of those
>> >> on-board audio interfaces that comes with most motherboards.
>> >
>> >In principle it is slightly complicated because of the possibility of
>> >unpredictably high peaks. But in practice this doesn't seem a problem
>> >in my experience and 16bit samples should be fine if you allow for
>> >enough headroom when setting the gain.
>> >
>
>> The unexpectedly high peaks are invariably ticks and scratches, and it
>> really doesn't matter if they overload - they need removing anyway.
>
>But if you overload the analogue section with a tick etc isn't there a
>chance it will effect the prog material immediately afterwards?
A very small one I would have thought. I can't remember the last time
I saw a circuit that didn't simply follow the waveform out of
limiting.
d
Jim Lesurf
<sp...@spam.com> wrote:
> On Thu, 10 Dec 2009 15:44:21 +0000 (GMT), "Dave Plowman (News)"
> <da...@davenoise.co.uk> wrote:
> >In article <4b20f7f9....@news.eternal-september.org>, Don Pearce
> >> The unexpectedly high peaks are invariably ticks and scratches, and
> >> it really doesn't matter if they overload - they need removing anyway.
> >
> >But if you overload the analogue section with a tick etc isn't there a
> >chance it will effect the prog material immediately afterwards?
> A very small one I would have thought. I can't remember the last time I
> saw a circuit that didn't simply follow the waveform out of limiting.
The stylus may take more time to recover and settle down in bad cases. But
there isn't much you can do about that further along the chain!
Johnny B Good
from sp...@spam.com (Don Pearce) contains these words:
> On Thu, 10 Dec 2009 13:24:53 +0000 (GMT), Jim Lesurf
> <no...@audiomisc.co.uk> wrote:
> >In article <BtOdnf1Sy__Ib73W...@giganews.com>, Arny
> >Krueger
> ><ar...@hotpop.com> wrote:
> >
> >
> >> Because of the LP format's inherent technical failings, digitizing LPs
> >> is not all that challenging of a task for even an one of those on-board
> >> audio interfaces that comes with most motherboards.
> >
> >In principle it is slightly complicated because of the possibility of
> >unpredictably high peaks. But in practice this doesn't seem a problem in my
> >experience and 16bit samples should be fine if you allow for enough
> >headroom when setting the gain.
Well, 16 bit samples allow for a theoretical dynamic range of 96db
which exceeds the best dynamic range of vynil by a good 25db so plenty
in hand to allow you to stay comfortably below the FSD 0db reference.
However, 16 bit ISA soundcards usually waste a good 15 to 20 db of this
by having a relatively high noise floor which demands that you try and
record as close to the 0db FSD level as is practical (you still have a
good 70db DR even in this case).
The 16 bit PCI cards tended to look better, noisefloorwise, by around
10 db or so but the improvement was largely lost when you were forced to
use recording levels a good 10 db lower in order to avoid the -4db
buffer amp clipping level.
> >
> The unexpectedly high peaks are invariably ticks and scratches, and it
> really doesn't matter if they overload - they need removing anyway.
Yes, it's true that clipping in the line in buffer amp of those
particular transient events can be "A Good Thing", but only if the
buffer amp doesn't respond in a nasty way which can spread the effects
over a larger slice of time than the event itself.
--
Regards, John.
Please remove the "ohggcyht" before replying.
The address has been munged to reject Spam-bots.
><(((°>
> I'd like to make some recordings, maybe transferring some gems from my
> vinyl collection to digital etc. I'm wondering whether I should use a
> better sound card than the onboard sound.
>
> I know one of the regulars here occasionally posts about an almost
> universal design flaw on sound cards where the input circuitry clips
> well below the potential ability of the A/D convertor or something. I
> did try recording from vinyl via a T/T preamp to a basic onboard sound
> card a few years ago. The preamp has no gain control and ISTR the result
> did sound slightly distorted as if clipped.
>
> I've got one of those old Santa Cruz/Sonic Fury cards lying around,
> which were reckoned to be pretty good in their time. Would it be worth
> installing that for recording? I found an old review:
>
> Audio Converters: Dual AC-97 2.1 audio codecs with hardware full-duplex
> for simultaneous record and playback and up to 48 kHz sample rates.
> 18-bit A/D converters for high-resolution recording. 20-bit D/A
> converters for high-resolution playback of up to 6 independent streams.
>
> Alternatively I could probably borrow my friend's EMI external USB sound
> adapter which he bought especially for semi-professional recording a few
> years back. Significantly better still?
>
Transfers from vinyl:
I recall spending ages trying this with several internal PCI sound cards
and after lots of effort, playing around with scratch filters, noise
reduction and recording at various trial volume levels, I was still
unhappy with the results.
I then setup an old PC with a Creative 64 AWE Gold ISA interface sound
card installed.
The end results were significantly better but I was still unimpressed with
my eventual results.
(Still got the Creative card should anyone want it)
Later I succumbed to temptation and downloaded in mp3 format the content
that I'd wanted from vinyl.
Eventually there remained only one album I couldn't find.
Quality was way better than anything I'd achieved.
Not sure if I infringed copyright but I did it on the basis that I owned
it on vinyl therefore had paid for it at some time in the distant past.
If making original recordings from microphone or other sound pickup
devices, then I'm sure there are better equipments for the job than
desktop PC's which are inherently noisy. Actually a laptop may be better
if you can do the job on batteries.
El Gringo
I've had good results with a Delta 66 card. It is an internal card,
but the inputs and outputs are on a breakout box.