Recording Signal attenuation questions
 

Guilty about the ludicrous number of gardening mags she consumes, Swim
bought me a couple of hifi comix yesterday (I'm actually so 'off them',
these days!) and in one of them I saw a mention that attenuation of signals
for computer recording purposes should be done 'pre-computer' because the
software 'volume sliders' wreck the sound quality.....???

Anyone care to confirm or deny this and would this mean it is best to leave
the sliders 'maxxed out' if one is attenuating 'pre computer'?

Anyhoo, moot AFAIAC, as I can not get a recording from my vinyl setup
without having the slider set at the absolute minimum or I get clipping, as
anyone who has bothered to listen to any of the wacky clips I post from time
to time**, will tell. So I'm plotting to construct a little attenuator which
I envisage as not much more than an Alps pot in a little box with phono
sockets IN and OUT, wired accordingly.

Too simple? Am I missing summat here? (Like everything you buy seems to have
a tiny little resistor stuck in it for some reason!)



**On that subject, I notice no-one has had a go at my truncated'name that
tune' clip:

http://www.apah69.dsl.pipex.com/keit...aughtybits.mp3

Too obscure or just too ****ty a recording, eh?

;-)

Recording Signal attenuation questions
 

"Keith G" wrote in message


Guilty about the ludicrous number of gardening mags she consumes, Swim
bought me a couple of hifi comix yesterday (I'm actually so 'off
them', these days!) and in one of them I saw a mention that
attenuation of signals for computer recording purposes should be done
'pre-computer' because the software 'volume sliders' wreck the sound
quality.....???

Oh, boy.

Anyone care to confirm or deny this and would this mean it is best to
leave the sliders 'maxxed out' if one is attenuating 'pre computer'?

Keith I know you didn't say this, but I'd like to clarify a related point:
Potential myth number one might be that there is a inherent sound quality
advantage one way or the other between digital audio and computer audio.
There isn't.

To review, there are basically three ways to record audio digitally:

(1) A general purpose (PC, Apple) computer with a digital audio interface
and appropriate software
(2) A dedicated digital recorder e.g., A-DAT or hard drive recorder
(3) A DAW that is not obvioiusly based on a general-purpose computer.

In terms of potential for quality sound, they are all equal. In fact, a
goodly proportion of all modern hard drive recorders are actually
proprietary computers running an OS that is neither MS nor Apple. The key
component of all three kinds of products is a digital audio interface, and
in fact some of digital audio interfaces can be interchanged between the
three types of products.

That all said, good digital audio interfaces have vastly more dynamic range
than analog tape. The best ones have vastly more dynamic range than anybody
is likely to ever need. The problem then becomes what profitable thing to do
with all this dynamic range, and the answer is headroom. Given that any of
the good ones figuratively have dynamic range to burn, the best way to burn
it is to record at more conservatively low levels, and leave lots of
headroom in case the musos get frisky, etc.

Anyhoo, moot AFAIAC, as I can not get a recording from my vinyl setup
without having the slider set at the absolute minimum or I get
clipping, as anyone who has bothered to listen to any of the wacky
clips I post from time to time**, will tell.

As I recall, you're using a consumer sound card. If you got your hands on
one that was designed for audio production, you might find things a little
different. Consumer audio interfaces clip someplace around 1 volt. Audio
interfaces designed for the audio production environment clip someplace
between 1.7 and 8 volts.

So I'm plotting to
construct a little attenuator which I envisage as not much more than
an Alps pot in a little box with phono sockets IN and OUT, wired
accordingly.

Go for it. However, bear in mind that some consumer sound cards really need
to be operating just below clipping to deliver adequate dynamic range.

Recording Signal attenuation questions
 

"Keith G" wrote in message
...

Guilty about the ludicrous number of gardening mags she consumes, Swim
bought me a couple of hifi comix yesterday (I'm actually so 'off them',
these days!) and in one of them I saw a mention that attenuation of
signals
for computer recording purposes should be done 'pre-computer' because the
software 'volume sliders' wreck the sound quality.....???

Anyone care to confirm or deny this and would this mean it is best to
leave
the sliders 'maxxed out' if one is attenuating 'pre computer'?

Anyhoo, moot AFAIAC, as I can not get a recording from my vinyl setup
without having the slider set at the absolute minimum or I get clipping,
as
anyone who has bothered to listen to any of the wacky clips I post from
time
to time**, will tell. So I'm plotting to construct a little attenuator
which
I envisage as not much more than an Alps pot in a little box with phono
sockets IN and OUT, wired accordingly.

Too simple? Am I missing summat here? (Like everything you buy seems to
have
a tiny little resistor stuck in it for some reason!)



**On that subject, I notice no-one has had a go at my truncated'name that
tune' clip:

http://www.apah69.dsl.pipex.com/keit...aughtybits.mp3

Too obscure or just too ****ty a recording, eh?

;-)





You are right, an external attenuator is a GOOD thing. The audio going into
the card will be amplified before being converted to digital on which the
software slider work. It is therefore very easy to overload the input and
the sliders will make no difference - the sound is already distorted! I
know, I found out the hard way.


--

Woody

Recording Signal attenuation questions
 

Hi,

In message , Keith G
writes

Guilty about the ludicrous number of gardening mags she consumes, Swim
bought me a couple of hifi comix yesterday (I'm actually so 'off them',
these days!) and in one of them I saw a mention that attenuation of signals
for computer recording purposes should be done 'pre-computer' because the
software 'volume sliders' wreck the sound quality.....???

That sounds likely. A lot of sound cards these days don't have any
analogue attenuation on the inputs, so they take whatever you feed them,
digitise it, and then perform any gain changes digitally. Digital gain
changes on cheap sound cards can be a bad thing, and if the analogue
input is too hot for the card, then it can be difficult to avoid
clipping.

Anyone care to confirm or deny this and would this mean it is best to leave
the sliders 'maxxed out' if one is attenuating 'pre computer'?

That's what I do. I use a low end Spirit Folio mixer between the source
(RIAA preamp) and the card inputs. I set the levels on the mixer, while
keeping an eye on the level meters of the sound card. The metering on
the Folio is almost worthless anyway, and I only use it to get the
signal levels vaguely right.

My signal path goes TT Gram amp Folio (stereo in) sound card.
The Folio has a couple of RIAA preamps but they aren't very good, so I
avoid them.


Anyhoo, moot AFAIAC, as I can not get a recording from my vinyl setup
without having the slider set at the absolute minimum or I get clipping, as
anyone who has bothered to listen to any of the wacky clips I post from time
to time**, will tell. So I'm plotting to construct a little attenuator which
I envisage as not much more than an Alps pot in a little box with phono
sockets IN and OUT, wired accordingly.

That will probably be fine. It will introduce a change in the input and
output impedances, but if you pick the right value pot I doubt you'll
have any problems. It will probably depend on how fussy the preamp
feeding the pot is about the load it sees.

Too simple? Am I missing summat here? (Like everything you buy seems to have
a tiny little resistor stuck in it for some reason!)

Simple is good :-)

If it was me, I'd try it and see. Worst case I reckon you might need to
add a couple of resistors if the preamp output wants to see a high
impedance load. Have a look at
http://www.users.bigpond.com/aagreen/passive01.html (just for circuit
ideas - some of the parts comments are silly), or you could always ask
Mr. Pinkerton nicely if he'll share his passive attenuator circuit with
you...

**On that subject, I notice no-one has had a go at my truncated'name that
tune' clip:

http://www.apah69.dsl.pipex.com/keit...aughtybits.mp3

Too obscure or just too ****ty a recording, eh?

Too obscure! Maybe Donizetti on amphetamines?

--
Regards,
Glenn Booth

Recording Signal attenuation questions
 

"Arny Krueger" wrote in message
...
"Keith G" wrote in message


Guilty about the ludicrous number of gardening mags she consumes, Swim
bought me a couple of hifi comix yesterday (I'm actually so 'off
them', these days!) and in one of them I saw a mention that
attenuation of signals for computer recording purposes should be done
'pre-computer' because the software 'volume sliders' wreck the sound
quality.....???

Oh, boy.

Anyone care to confirm or deny this and would this mean it is best to
leave the sliders 'maxxed out' if one is attenuating 'pre computer'?

Keith I know you didn't say this,


It's in the August 2004 editions of either HFW or HFN - I haven't been able
to find it again yet. But there is a huge article in HFW (pp 76 - 81) that
opens up a whole new can of worms for me on the subject of LP HD. See this
strapline for an idea.....

http://www.apah69.dsl.pipex.com/keit...w/L1040425.JPG

.....so I've got a lot of catching up to do. (The extra resolution and
bandwidth of 24/96 sounds appealing and I think I'm about to revise my
thinking as a result of this bit of propaganda.....!!!)


snipped but studied - 'frisky musos'??? :-)

As I recall, you're using a consumer sound card. If you got your hands on
one that was designed for audio production, you might find things a little
different. Consumer audio interfaces clip someplace around 1 volt. Audio
interfaces designed for the audio production environment clip someplace
between 1.7 and 8 volts.


Actually I'm using only the computer's motherboard sound atm. I'm trusting
that the 'digital bits' are not being dinged up too much in the (possibly
naive and receding) idea that 'a bit is a bit'.....

My use of digital audio has changed somewhat lately - having assembled a
decent little 'computer audio' (ss amp and speakers) for 'background music',
I no longer play music straight from the hard disk and therefore ditched the
cheapo soundacard which was OK to get a digital signal to an outboard DAC,
but played merry hell with any attempts to record vinyl to HD.

As an example, I have uploaded this track.....

http://www.apah69.dsl.pipex.com/keit...ould%20Fly.mp3

....(actually a CD rip, selected only for its modest filesize) of the sort of
thing which sounds perfectly OK from the computer setup but, even though it
is only a 128MP3 (I'm recording at better bitrates these days) it sounds
really quite fine when burned to CDR/RW as an audio CD and played over my
audio setup proper.



So I'm plotting to
construct a little attenuator which I envisage as not much more than
an Alps pot in a little box with phono sockets IN and OUT, wired
accordingly.

Go for it. However, bear in mind that some consumer sound cards really
need
to be operating just below clipping to deliver adequate dynamic range.


My instinct would actually be to pull back from 'max' a tad, I have to
say......

Recording Signal attenuation questions
 

"Woody" wrote


You are right, an external attenuator is a GOOD thing. The audio going
into
the card will be amplified before being converted to digital on which the
software slider work. It is therefore very easy to overload the input and
the sliders will make no difference - the sound is already distorted! I
know, I found out the hard way.



Yes, I agree - I feel that getting the signal sorted *before* it gets into
the digital domain can only be a good thing, but I also reckon a nice little
knob to twiddle, by the computer, is going to be a far more satisfying way
to set recording levels (on the fly, watching the meters) than poncing
about, flicking from screen to screen....

Recording Signal attenuation questions
 

On Thu, 29 Jul 2004 18:07:31 +0100, "Keith G"
wrote:

As an example, I have uploaded this track.....

http://www.apah69.dsl.pipex.com/keit...ould%20Fly.mp3

...(actually a CD rip, selected only for its modest filesize) of the sort of
thing which sounds perfectly OK from the computer setup but, even though it
is only a 128MP3 (I'm recording at better bitrates these days) it sounds
really quite fine when burned to CDR/RW as an audio CD and played over my
audio setup proper.

I think the reason this track sounds so nice is that her voice has
been recorded straight, with no autotune turning it into a vocoder. I
suspect that this is the big difference you hear between vinyl and CD
generally - most vinyl predates that kind of messing.

It really is quite nice to hear somebody singing naturally with the
odd out-of-tune note here and there.

Who is it, BTW? - shades of Suzanne Vega there...

d

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

Recording Signal attenuation questions
 

"Glenn Booth" wrote

That's what I do. I use a low end Spirit Folio mixer between the source
(RIAA preamp) and the card inputs. I set the levels on the mixer, while
keeping an eye on the level meters of the sound card. The metering on
the Folio is almost worthless anyway, and I only use it to get the
signal levels vaguely right.

My signal path goes TT Gram amp Folio (stereo in) sound card.
The Folio has a couple of RIAA preamps but they aren't very good, so I
avoid them.


OK, looks like I'll be going:

TT Phono Stage Attenuator Computer or (dammit) Soundcard....


That will probably be fine. It will introduce a change in the input and
output impedances, but if you pick the right value pot I doubt you'll
have any problems. It will probably depend on how fussy the preamp
feeding the pot is about the load it sees.


I bet I get away with no added resistance...


Too simple? Am I missing summat here? (Like everything you buy seems to
have
a tiny little resistor stuck in it for some reason!)

Simple is good :-)

If it was me, I'd try it and see. Worst case I reckon you might need to
add a couple of resistors if the preamp output wants to see a high
impedance load. Have a look at
http://www.users.bigpond.com/aagreen/passive01.html (just for circuit
ideas - some of the parts comments are silly),


Excellent link - thanks. (Bit on the big side, but pretty much what I had on
mind with just the one pot, though....)


or you could always ask
Mr. Pinkerton nicely if he'll share his passive attenuator circuit with
you...

If you mean the one mentioned on his webpage.....

http://www.apah69.dsl.pipex.com/stewart_p/stewart_p.htm

.....then it's a bit rich for my pockets...!!!

:-)



**On that subject, I notice no-one has had a go at my truncated'name that
tune' clip:

http://www.apah69.dsl.pipex.com/keit...aughtybits.mp3

Too obscure or just too ****ty a recording, eh?

Too obscure! Maybe Donizetti on amphetamines?



OK, I've blown it now (needed the space, thanks to Pipex' buggering
about)) - it was Orff's 'Catulli Carmina'. The words were deemed to be too
racy to be printed on the album sleeve, but can be seen on...

http://www.duzan.org/gary/catulli_carmina.html

....if you are curious!

(The original post was made in a massively crossposted thread which had
'Latin' arguments in it - I just wondered if there were any real 'Latin
scholars' in any of these groups and also whether any of the 'musos' in any
of these groups recognised the music, or had even heard of it, come to
that......)

;-)

Recording Signal attenuation questions
 

"Don Pearce" wrote in message
...
On Thu, 29 Jul 2004 18:07:31 +0100, "Keith G"
wrote:

As an example, I have uploaded this track.....

http://www.apah69.dsl.pipex.com/keit...ould%20Fly.mp3

...(actually a CD rip, selected only for its modest filesize) of the sort
of
thing which sounds perfectly OK from the computer setup but, even though
it
is only a 128MP3 (I'm recording at better bitrates these days) it sounds
really quite fine when burned to CDR/RW as an audio CD and played over my
audio setup proper.

I think the reason this track sounds so nice is that her voice has
been recorded straight, with no autotune turning it into a vocoder. I
suspect that this is the big difference you hear between vinyl and CD
generally - most vinyl predates that kind of messing.

It really is quite nice to hear somebody singing naturally with the
odd out-of-tune note here and there.


That's probably because AFAIK she's not a singer as such - I think she's an
actress and/or model....???


Who is it, BTW?

Regina Lund - another in a long line of the 'Scandinavian Totty' that I'm
into (I wish.... :-) atm:

http://www.apah69.dsl.pipex.com/keit...w/fackoff.jpeg


- shades of Suzanne Vega there...

Funny you should say that - many such references in the review on this
excellent site (look under year 2000 near the bottom):

http://www.geocities.com/SunsetStrip...3/archives.htm


The album is 'Year Zero' and is excellent, if not a little 'sameyish',
throughout - nice 'presence', nice backing - not too much, just right IMO.

That track was not the best by far, if you liked that, you'll like this
better:

http://www.apah69.dsl.pipex.com/keit...ing%20Room.mp3

(Only ****e 128MP3s I'm afarid, I'll be re-ripping this at 192 or 256
sometime soon...)

And if both the tracks are dowloadable, then perhaps Pipex have stopped
truncating my webspace at 25 Mb and I'm getting the 50 Meg I'm paying
for....!!!!

Recording Signal attenuation questions
 

"Don Pearce" wrote in message
...
On Thu, 29 Jul 2004 18:07:31 +0100, "Keith G"
wrote:

As an example, I have uploaded this track.....

http://www.apah69.dsl.pipex.com/keit...ould%20Fly.mp3

...(actually a CD rip, selected only for its modest filesize) of the sort
of
thing which sounds perfectly OK from the computer setup but, even though
it
is only a 128MP3 (I'm recording at better bitrates these days) it sounds
really quite fine when burned to CDR/RW as an audio CD and played over my
audio setup proper.

I think the reason this track sounds so nice is that her voice has
been recorded straight, with no autotune turning it into a vocoder. I
suspect that this is the big difference you hear between vinyl and CD
generally - most vinyl predates that kind of messing.


Meant to say that you could be right here also - I find this album *very*
vinyl-like indeed.

It has that sense of 'real' and 'immediate' that I expect (and get) from
vinyl and also why I tend to prefer a CDR made from an LP to the 'straight
CD' equivalent....

(OK, there's mastering differences too and I've got plenty of vinyl where a
vocoder has been used.....)

;-)