8 Dec
2010
8 Dec
'10
4:26 p.m.
I have a DI box which has an XLR balanced output. I want to connect it
to my cheapo sound card (SBLive) through the (stereo) line in. Is this
possible? What would be the best way? Would a mono jack:XLR converter
be OK?
8 Dec
8 Dec
4:39 p.m.
On Wed, 8 Dec 2010, James Stone wrote:
I have a DI box which has an XLR balanced output. I
want to connect it
to my cheapo sound card (SBLive) through the (stereo) line in. Is this
possible? What would be the best way? Would a mono jack:XLR converter
be OK?
Are you wanting to convert to an unbalanced signal in
hardware (a cheap balan/transformer/DI) or in software (DSP
code to combine L and R to produce a mono stream) ??
-gabriel
4:43 p.m.
On Wed, Dec 8, 2010 at 3:39 PM, Gabriel M. Beddingfield
<gabrbedd(a)gmail.com> wrote:
On Wed, 8 Dec 2010, James Stone wrote:
I guess in hardware?
Thinking more about it, do I need to plug the DI out into a preamp
before it goes into the line in for the soundcard? (the instrument is
a bass guitar unamplified).
James
I have a DI box which has an XLR balanced output.
I want to connect it
to my cheapo sound card (SBLive) through the (stereo) line in. Is this
possible? What would be the best way? Would a mono jack:XLR converter
be OK?
Are you wanting to convert to an unbalanced signal in hardware (a cheap
balan/transformer/DI) or in software (DSP code to combine L and R to produce
a mono stream) ??
4:49 p.m.
On Wed, 8 Dec 2010, James Stone wrote:
I guess in hardware?
Thinking more about it, do I need to plug the DI out into a preamp
before it goes into the line in for the soundcard? (the instrument is
a bass guitar unamplified).
If you can, just skip the DI and plug the guitar straight
into the sound card's line-in.
-gabriel
5:01 p.m.
On Wed, Dec 8, 2010 at 3:49 PM, Gabriel M. Beddingfield
<gabrbedd(a)gmail.com> wrote:
On Wed, 8 Dec 2010, James Stone wrote:
I've tried that before, but (at least with an electric (non-bass)),
the sound was rather woolly and lacking in treble - I though due to
the mix of Hi-Z and line level input.
James
I guess in hardware?
Thinking more about it, do I need to plug the DI out into a preamp
before it goes into the line in for the soundcard? (the instrument is
a bass guitar unamplified).
If you can, just skip the DI and plug the guitar straight into the sound
card's line-in.
5:24 p.m.
On Wed, 8 Dec 2010, James Stone wrote:
I've tried that before, but (at least with an electric (non-bass)),
the sound was rather woolly and lacking in treble - I though due to
the mix of Hi-Z and line level input.
Sounds like you want to use a pre-amp, then.
AFAIK, this chain is effectively a NO-OP:
guitar --> DI box --> XLR --> DI/Transformer --> line in
..except for distortion introduced by the DI's. So
even if you get it set up -- you'll probably get the
same results as plugging straight in.
But, if you have a 2nd DI box or one of those $10
transformer things[1]... it's worth a try.
-gabriel
[1] http://en.wikipedia.org/wiki/Balun#Audio
I guess in hardware?
Thinking more about it, do I need to plug the DI out into a preamp
before it goes into the line in for the soundcard? (the instrument is
a bass guitar unamplified).
If you can, just skip the DI and plug the guitar straight into the sound
card's line-in. 
5:41 p.m.
James Stone wrote:
On Wed, Dec 8, 2010 at 3:49 PM, Gabriel M.
Beddingfield
<gabrbedd(a)gmail.com> wrote:
If you are connecting a guitar to a soundcard input you will almost
certainly need some kind of DI box to provide the necessary high
impedance input for the guitar otherwise you will get a dull "woolly"
sound - as you describe.
A balanced line has three conductors instead of the usual two. These
are the screen, and the two signal wires. The signal wires carry the
audio signal, but in opposite polarity.
In a conventional balanced input stage, the two signal inputs are
subtracted from each other - and being of opposite polarity, the result
is the original audio. However, the important advantage of this method
is that any noise or interference induced on the wire(s) will be of the
same polarity on both signal conductors (in theory) and so will be
cancelled out (this is what common-mode rejection is all about).
You can get a signal for your single-ended input to the soundcard
between either signal phase and the screen. To avoid any phase
inversions, connect the positive signal out from the DI box (XLR pin 2)
to the signal in on your sound card input (Tip of the jack connector),
and the screen (XLR pin 1 ) to the ground on the soundcard input (Body
of the jack connector).
This is not the ideal way to convert between balanced and unbalanced
signals, but it will provide a working solution. There's some more info
here:
http://www.rane.com/note110.html
As for whether the signal level will need more amplification, that
depends on the DI box. If you can feed a line level mixer input, then
probably not, but try it and see.
Mike
On Wed, 8 Dec 2010, James Stone wrote:
I've tried that before, but (at least with an electric (non-bass)),
the sound was rather woolly and lacking in treble - I though due to
the mix of Hi-Z and line level input.
James
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
http://lists.linuxaudio.org/listinfo/linux-audio-user
I guess in hardware?
Thinking more about it, do I need to plug the DI out into a preamp
before it goes into the line in for the soundcard? (the instrument is
a bass guitar unamplified).
If you can, just skip the DI and plug the guitar
straight into the sound
card's line-in. 
7:14 p.m.
On Wednesday 08 December 2010 18:00:34 linuxdsp wrote:
James Stone wrote:
If the di-box output is transformer-based, the level and signal-quality will
be the same regardless whether you connect it to a balanced input or an
unbalanced one. The key is that normally the transformer would output a
voltage-difference between hot and cold signal. if you connect cold to the
ground of the receiver, the transformer will create the same voltage between
your ground and hot signal. Even if the ground of the receiver is in fact at
+60V potential it will create its audio signal with respect to that. This is
the main reason to use transformer-based outputs in devices and di-boxes.
Have fun,
Arnold
On Wed, Dec 8, 2010 at 3:49 PM, Gabriel M.
Beddingfield
<gabrbedd(a)gmail.com> wrote:
If you are connecting a guitar to a soundcard input you will almost
certainly need some kind of DI box to provide the necessary high
impedance input for the guitar otherwise you will get a dull "woolly"
sound - as you describe.
A balanced line has three conductors instead of the usual two. These
are the screen, and the two signal wires. The signal wires carry the
audio signal, but in opposite polarity.
In a conventional balanced input stage, the two signal inputs are
subtracted from each other - and being of opposite polarity, the result
is the original audio. However, the important advantage of this method
is that any noise or interference induced on the wire(s) will be of the
same polarity on both signal conductors (in theory) and so will be
cancelled out (this is what common-mode rejection is all about).
You can get a signal for your single-ended input to the soundcard
between either signal phase and the screen. To avoid any phase
inversions, connect the positive signal out from the DI box (XLR pin 2)
to the signal in on your sound card input (Tip of the jack connector),
and the screen (XLR pin 1 ) to the ground on the soundcard input (Body
of the jack connector).
This is not the ideal way to convert between balanced and unbalanced
signals, but it will provide a working solution. There's some more info
here:
http://www.rane.com/note110.html
As for whether the signal level will need more amplification, that
depends on the DI box. If you can feed a line level mixer input, then
probably not, but try it and see. On Wed, 8 Dec 2010, James Stone wrote:
I've tried that before, but (at least with an electric (non-bass)),
the sound was rather woolly and lacking in treble - I though due to
the mix of Hi-Z and line level input. I guess in hardware?
Thinking more about it, do I need to plug the DI out into a preamp
before it goes into the line in for the soundcard? (the instrument is
a bass guitar unamplified).
If you can, just skip the DI and plug the guitar straight into the sound
card's line-in. 
9:19 p.m.
On Wed, Dec 08, 2010 at 05:00:34PM +0000, linuxdsp wrote:
James Stone wrote:
I have a slightly different question: I need to convert a non-balanced consumer-grade
headphone input (from a laptop or iPod), to a non-balanced consumer-grade amplifier
(Cambridge SoundWorks).... but with complete ground isolation. I'm guessing a simple
transformer should do the trick, but the question is: WHICH transformer? What should the
specs be in order to get the impedance right for both sides?
-ken
On Wed, Dec 8, 2010 at 3:49 PM, Gabriel M.
Beddingfield
<gabrbedd(a)gmail.com> wrote:
If you are connecting a guitar to a soundcard input you will almost
certainly need some kind of DI box to provide the necessary high
impedance input for the guitar otherwise you will get a dull "woolly"
sound - as you describe.
A balanced line has three conductors instead of the usual two. These
are the screen, and the two signal wires. The signal wires carry the
audio signal, but in opposite polarity.
In a conventional balanced input stage, the two signal inputs are
subtracted from each other - and being of opposite polarity, the result
is the original audio. However, the important advantage of this method
is that any noise or interference induced on the wire(s) will be of the
same polarity on both signal conductors (in theory) and so will be
cancelled out (this is what common-mode rejection is all about).
You can get a signal for your single-ended input to the soundcard
between either signal phase and the screen. To avoid any phase
inversions, connect the positive signal out from the DI box (XLR pin 2)
to the signal in on your sound card input (Tip of the jack connector),
and the screen (XLR pin 1 ) to the ground on the soundcard input (Body
of the jack connector).
This is not the ideal way to convert between balanced and unbalanced
signals, but it will provide a working solution. There's some more info
here:
http://www.rane.com/note110.html
As for whether the signal level will need more amplification, that
depends on the DI box. If you can feed a line level mixer input, then
probably not, but try it and see.
On Wed, 8 Dec 2010, James Stone wrote:
I've tried that before, but (at least with an electric (non-bass)),
the sound was rather woolly and lacking in treble - I though due to
the mix of Hi-Z and line level input.
James
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
http://lists.linuxaudio.org/listinfo/linux-audio-user
I guess in hardware?
Thinking more about it, do I need to plug the DI out into a preamp
before it goes into the line in for the soundcard? (the instrument is
a bass guitar unamplified).
If you can, just skip the DI and plug the guitar
straight into the sound
card's line-in. 
9:41 p.m.
On Wed, Dec 08, 2010 at 12:18:31PM -0800, Ken Restivo wrote:
I have a slightly different question: I need to
convert a non-balanced consumer-grade headphone input (from a laptop or iPod), to a
non-balanced consumer-grade amplifier (Cambridge SoundWorks).... but with complete ground
isolation. I'm guessing a simple transformer should do the trick, but the question is:
WHICH transformer? What should the specs be in order to get the impedance right for both
sides?
Don't worry about impedances, they don't have to be matched
unless there's a few km of wire between the two.
Headphone out is low Z, amp in will be 10k or more. Any line
level 1:1 audio transfo will do. You can by them as XLR inserts
or just bare.
Ciao,
--
FA
There are three of them, and Alleline.
7:09 p.m.
On Wed, 8 Dec 2010 16:01:40 +0000
James Stone <jamesmstone(a)gmail.com> wrote:
On Wed, Dec 8, 2010 at 3:49 PM, Gabriel M.
Beddingfield
<gabrbedd(a)gmail.com> wrote:
A guitar pickup sends out around 20 - 50 mV and wants to see between 470k and
1M. A sound card line input is typically abut 300mV and 10 - 47k so rather a
mismatch!
A DI box might not help much unless it specifically has a high impedance
input and has around 20dB of gain.
Sometimes you can cheat by putting a resistor (470k - 1M) in series with a
microphone input, but it will tend to be rather noisy.
--
Will J Godfrey
http://www.musically.me.uk
Say you have a poem and I have a tune.
Exchange them and we can both have a poem, a tune, and a song.
On Wed, 8 Dec 2010, James Stone wrote:
I've tried that before, but (at least with an electric (non-bass)),
the sound was rather woolly and lacking in treble - I though due to
the mix of Hi-Z and line level input.
James I guess in hardware?
Thinking more about it, do I need to plug the DI out into a preamp
before it goes into the line in for the soundcard? (the instrument is
a bass guitar unamplified).
If you can, just skip the DI and plug the guitar straight into the sound
card's line-in.
7:21 p.m.
On Wed, Dec 08, 2010 at 06:09:20PM +0000, Folderol wrote:
A guitar pickup sends out around 20 - 50 mV and wants
to see between 470k and
1M. A sound card line input is typically abut 300mV and 10 - 47k so rather a
mismatch!
A DI box might not help much unless it specifically has a high impedance
input and has around 20dB of gain.
DI boxes are supposed to have such high input impedance.
20 to 50 mv into a nominal -10dBm consumer type line input
feeding a 24-bit converter could work fine without extra
gain. You may need some extra 'digital gain' if the level
of the instrument needs to be quite high in the mix.
Ardour doesn't provide 'input gain', and its fader has
only 6dB positive gain, but an amp or compressor plugin
will do the trick.
Ciao,
--
FA
There are three of them, and Alleline.
5:42 p.m.
onsdag 08 december 2010 16.26.48 skrev James Stone:
I have a DI box which has an XLR balanced output. I
want to connect it
to my cheapo sound card (SBLive) through the (stereo) line in. Is this
possible? What would be the best way? Would a mono jack:XLR converter
be OK?
If you are brave and feel lucky today: Try this from WP:
http://en.wikipedia.org/wiki/Balanced_audio#Converters
Jostein
6:42 p.m.
I don't know why complicate this. just buy a cable with TRS on one and XLR on the
other side. In Linux you will have the positive signal on one chanel and the negative on
the other (don't rember now wich will be left and wich right). you can now ignore the
negative chanel or even process both of them in software to get noise canceled.
Fabio
Em quarta-feira 08 dezembro 2010, às 13:26:48, James Stone escreveu:
I have a DI box which has an XLR balanced output. I
want to connect it
to my cheapo sound card (SBLive) through the (stereo) line in. Is this
possible? What would be the best way? Would a mono jack:XLR converter
be OK?
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
http://lists.linuxaudio.org/listinfo/linux-audio-user
6:47 p.m.
there are XLR to TS cables to, wich only conect the positive line to the TS.
Em quarta-feira 08 dezembro 2010, às 13:26:48, James Stone escreveu:
I have a DI box which has an XLR balanced output. I
want to connect it
to my cheapo sound card (SBLive) through the (stereo) line in. Is this
possible? What would be the best way? Would a mono jack:XLR converter
be OK?
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
http://lists.linuxaudio.org/listinfo/linux-audio-user
5053
days inactive
5053
days old
linux-audio-user@lists.linuxaudio.org
14 comments
9 participants
participants (9)
-
Arnold Krille -
Fabio -
Folderol -
fons＠kokkinizita.net -
Gabriel M. Beddingfield -
James Stone -
Jostein Chr. Andersen -
Ken Restivo -
linuxdsp