Does anyone know a way to take an audio signal and output it multiple times with different amplitude and phases tia sal2
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Posted by please_post_to_groups on November 12, 2008, 2:04 pm
Please log in for more thread options with different amplitude and phases tia sal2 Greetings All I have one source for an audio signal and would like to send it to 8 different outputs simultaneously, but would like to be able to change the phase and amplitude of each of the 8 outputs separately. I was thinking of using 8 small amplifiers (which isn’t cheap) to increase the amplitude of the 8 output signals but I’m not sure how I can change the phase of each signal separately. Is there a product on the market that is inexpensive or can someone recommend a circuit I could build? I would use an oscilloscope to make sure the phase and amplitude of each of the 8 outputs is where I would want it. Example: Source is a sine wave generated by a laptop Output 1) starts at 0 degrees Output 2) starts at 10 degrees out of phase increase amplitude by 1 volt Output 3) starts at 15 degrees out of phase Output 4) starts at 40 degrees out of phase Output 5) starts at 60 degrees out of phase increase amplitude by 3 volts Output 6) starts at 100 degrees out of phase Output 7) starts at 120 degrees out of phase Output 8) starts at 126 degrees out of phase alt.sci.physics.acoustics,sci.electronics.basics,sci.electronics.misc,rec.audio.misc Tia Sal2 | |||||||||||||||||||
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Posted by John Fields on November 12, 2008, 2:53 pm
Please log in for more thread options >simultaneously, but would like to be able to change the phase and amplitude of
each of the
>8 outputs separately.
amplitude
> >I was thinking of using 8 small amplifiers (which isn’t cheap) to increase the >of the 8 output signals but I’m not sure how I can change the phase of each
signal separately.
>Is there a product on the market that is inexpensive or can someone recommend a
circuit
>I could build?
8 outputs
> >I would use an oscilloscope to make sure the phase and amplitude of each of the >is where I would want it.
> >Example: >Source is a sine wave generated by a laptop > >Output 1) starts at 0 degrees >Output 2) starts at 10 degrees out of phase increase amplitude by 1 volt >Output 3) starts at 15 degrees out of phase >Output 4) starts at 40 degrees out of phase >Output 5) starts at 60 degrees out of phase increase amplitude by 3 volts >Output 6) starts at 100 degrees out of phase >Output 7) starts at 120 degrees out of phase >Output 8) starts at 126 degrees out of phase --- View in Courier: IN>---+------------------------------------[OPAMP]--->OUT1
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+--[ADC]--+-[LUT1]--[DAC]--[FILTER]--[OPAMP]--->OUT2
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+-[LUT2]--[DAC]--[FILTER]--[OPAMP]--->OUT3
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+-[LUT3]--[DAC]--[FILTER]--[OPAMP]--->OUT4
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+-[LUT4]--[DAC]--[FILTER]--[OPAMP]--->OUT5
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+-[LUT5]--[DAC]--[FILTER]--[OPAMP]--->OUT6
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+-[LUT6]--[DAC]--[FILTER]--[OPAMP]--->OUT7
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+-[LUT7]--[DAC]--[FILTER]--[OPAMP]--->OUT8
JF | |||||||||||||||||||
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Posted by John Fields on November 12, 2008, 5:42 pm
Please log in for more thread options On Wed, 12 Nov 2008 13:53:31 -0600, John Fields
>On Wed, 12 Nov 2008 19:04:07 GMT, please_post_to_groups
> >>Does anyone know a way to take an audio signal and output it multiple times
outputs
>>with different amplitude and phases tia sal2 >> >>Greetings All >> >>I have one source for an audio signal and would like to send it to 8 different >>simultaneously, but would like to be able to change the phase and amplitude of
each of the
>>8 outputs separately.
amplitude
>> >>I was thinking of using 8 small amplifiers (which isn’t cheap) to increase the >>of the 8 output signals but I’m not sure how I can change the phase of each
signal separately.
>>Is there a product on the market that is inexpensive or can someone recommend
a circuit
>>I could build?
the 8 outputs
>> >>I would use an oscilloscope to make sure the phase and amplitude of each of >>is where I would want it.
>> >>Example: >>Source is a sine wave generated by a laptop >> >>Output 1) starts at 0 degrees >>Output 2) starts at 10 degrees out of phase increase amplitude by 1 volt >>Output 3) starts at 15 degrees out of phase >>Output 4) starts at 40 degrees out of phase >>Output 5) starts at 60 degrees out of phase increase amplitude by 3 volts >>Output 6) starts at 100 degrees out of phase >>Output 7) starts at 120 degrees out of phase >>Output 8) starts at 126 degrees out of phase >
>--- >View in Courier: > >IN>---+------------------------------------[OPAMP]--->OUT1
> |
---
> +--[ADC]--+-[LUT1]--[DAC]--[FILTER]--[OPAMP]--->OUT2 > | > +-[LUT2]--[DAC]--[FILTER]--[OPAMP]--->OUT3 > | > +-[LUT3]--[DAC]--[FILTER]--[OPAMP]--->OUT4 > | > +-[LUT4]--[DAC]--[FILTER]--[OPAMP]--->OUT5 > | > +-[LUT5]--[DAC]--[FILTER]--[OPAMP]--->OUT6 > | > +-[LUT6]--[DAC]--[FILTER]--[OPAMP]--->OUT7 > | > +-[LUT7]--[DAC]--[FILTER]--[OPAMP]--->OUT8 > > Aaarrghhh!!! That won't work. JF | |||||||||||||||||||
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Posted by Marsh Ray on November 12, 2008, 7:04 pm
Please log in for more thread options On Nov 12, 1:04=A0pm, please_post_to_groups
> Does anyone know a way to take an audio signal and output it multiple tim=
es
> with different amplitude and phases tia sal2
ase the amplitude
> [] > I was thinking of using 8 small amplifiers (which isn=92t cheap) to incre= > of the 8 output signals but I=92m not sure how I can change the phase of =
each signal separately.
You should probably think in terms of little amplifier blocks. There's a lot of introductory material on the web if you search for 'op amp'. http://en.wikipedia.org/wiki/Operational_amplifier If you're building a basic circuit for audio frequencies, these are dirt cheap. You can get 4 or more on an inexpensive chip. =A0 > [...]
> Example: > Source is a sine wave generated by a laptop If you're using a sound card output, can you output the signal on the left and right channels, 90 degrees out of phase where it starts? That will simplify things greatly! If not, you'll need to generate a 90 degree phase shifted signal from the source. The simple circuits I'm familiar with are highly frequency dependent, but some of the wizards on this group may know some tricks. After you have 0 and 90 degree signals (call them s0 and s90) at equal amplitudes, you just need seven 2-channel mixers and some trigonometry. Assuming output amplitutde of 1 V. > Output 1) starts at 0 degrees
You've got that already.
> Output 2) starts at 10 degrees out of phase increase amplitude by 1 volt
Mostly s0, with the appropriate amount of s90 to shift phase. Increase
gain on both s0 and s90 to get increase the overall amplitude. s0 gain =3D 2*cos(10 deg) s90 gain =3D 2*sin(10 deg) > Output 3) starts at 15 degrees out of phase
s0*cos(15 deg) + s90*sin(15 deg)
> Output 4) starts at 40 degrees out of phase
s0*cos(40 deg) + s90*sin(40 deg)
> Output 5) starts at 60 degrees out of phase increase amplitude by 3 volts
s0*4*cos(60 deg) + s90*4*sin(60 deg)
> Output 6) starts at 100 degrees out of phase
> Output 7) starts at 120 degrees out of phase > Output 8) starts at 126 degrees out of phase For phase shifts >90, you calculate it the same, however, be aware
that one or both gains (from sin or cos) are going to be negative.
Depending on how you're programming your mixer/amplifiers, this may work automatically. Worst case, you just send your two input signals through unity gain inverting amplifiers (a simple op amp circuit) to get 180 and 270 degree signals. This makes a total of four inputs to each of your seven mixers, though no more than two will be nonzero at any given time. - Marsh | |||||||||||||||||||
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Posted by Bob Masta on November 13, 2008, 8:49 am
Please log in for more thread options On Wed, 12 Nov 2008 16:04:04 -0800 (PST), Marsh
>On Nov 12, 1:04=A0pm, please_post_to_groups
>> Does anyone know a way to take an audio signal and output it multiple tim=
>es
>> with different amplitude and phases tia sal2
>> [] >> I was thinking of using 8 small amplifiers (which isn=92t cheap) to incre= >ase the amplitude
>> of the 8 output signals but I=92m not sure how I can change the phase of =
>each signal separately.
> >You should probably think in terms of little amplifier blocks. There's >a lot of introductory material on the web if you search for 'op amp'. >http://en.wikipedia.org/wiki/Operational_amplifier > >If you're building a basic circuit for audio frequencies, these are >dirt cheap. You can get 4 or more on an inexpensive chip. > =A0 >> [...]
>> Example: >> Source is a sine wave generated by a laptop >
>If you're using a sound card output, can you output the signal on the >left and right channels, 90 degrees out of phase where it starts? That >will simplify things greatly! > >If not, you'll need to generate a 90 degree phase shifted signal from >the source. The simple circuits I'm familiar with are highly frequency >dependent, but some of the wizards on this group may know some tricks. > >After you have 0 and 90 degree signals (call them s0 and s90) at equal >amplitudes, you just need seven 2-channel mixers and some >trigonometry. Assuming output amplitutde of 1 V. > >> Output 1) starts at 0 degrees
>You've got that already.
> >> Output 2) starts at 10 degrees out of phase increase amplitude by 1 volt
>Mostly s0, with the appropriate amount of s90 to shift phase. Increase
>gain on both s0 and s90 to get increase the overall amplitude. > >s0 gain =3D 2*cos(10 deg) >s90 gain =3D 2*sin(10 deg) > >> Output 3) starts at 15 degrees out of phase
>s0*cos(15 deg) + s90*sin(15 deg)
> >> Output 4) starts at 40 degrees out of phase
>s0*cos(40 deg) + s90*sin(40 deg)
> >> Output 5) starts at 60 degrees out of phase increase amplitude by 3 volts
>s0*4*cos(60 deg) + s90*4*sin(60 deg)
> >> Output 6) starts at 100 degrees out of phase
>> Output 7) starts at 120 degrees out of phase >> Output 8) starts at 126 degrees out of phase >
>For phase shifts >90, you calculate it the same, however, be aware >that one or both gains (from sin or cos) are going to be negative. >Depending on how you're programming your mixer/amplifiers, this may >work automatically. Worst case, you just send your two input signals >through unity gain inverting amplifiers (a simple op amp circuit) to >get 180 and 270 degree signals. This makes a total of four inputs to >each of your seven mixers, though no more than two will be nonzero at >any given time. > >- Marsh This is excellent advice, and is the simplest solution yet! Since it only requires 2 outputs from the sound card, the (free) Daqarta signal generator create the 0 and 90 degree signals with ease. The beauty of your approach is that once the various mixer levels are set, it will work with any arbitrary generated frequency as long as the phases are maintained at 90 degree separation. You can even generate a frequency sweep, or use FM, etc and everything will track. To the OP: Let me know if you need any advice on how to set up the signals with Daqarta. Best regards, Bob Masta DAQARTA v4.51 Data AcQuisition And Real-Time Analysis www.daqarta.com Scope, Spectrum, Spectrogram, Sound Level Meter FREE Signal Generator Science with your sound card! | |||||||||||||||||||
>with different amplitude and phases tia sal2
>
>Greetings All
>
>I have one source for an audio signal and would like to send it to 8 different