Does anyone know a way to take an audio signal and output it multiple times with different amplitude

[please_post_to_groups]

Does anyone know a way to take an audio signal and output it multiple times
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

 

[Marsh Ray]

Does anyone know a way to take an audio signal and output it multiple times
with different amplitude and phases tia sal2
[]
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.

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.
 

[...]
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 = 2*cos(10 deg)
s90 gain = 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

 

[Andy]

Does anyone know a way to take an audio signal and output it multiple times
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?

Low-Cost Audio Delay Line Uses 1-Bit ADC

 

[Eeyore]

Does anyone know a way to take an audio signal and output it multiple times
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.

Amplitude is easy. Phase shifters only provide x degrees of shift at one single frequency. That is
inherent in the concept of sound (and other) waves.

Graham

 

[[email protected]]

On Wed, 12 Nov 2008 19:04:07 GMT,
please_post_to_groups
<please_post_to_groups@post_to_groups_please.com>
wrote:












If this only has to operate at a single fixed
frequency, this is fairly straightforward.  You
can use an "all-pass" filter that shifts phase
without changing level.  (Add gain or attenuation
as needed.)  The basic circuit uses an op-amp in
what looks sorta like a classic difference amp
configuration, but with the + and -  input
resistors tied together.  That alone would be a
"do nothing" circuit because the inverting gain
and the non-inverting gain would cancel each other
out at all input frequencies.  

However, you make the non-inverting input phase
sensitive by replacing one of the resistors with a
capacitor.

The two non-inverting resistors normally make a
2:1 voltage divider, so if you replace the ground
resistor with a cap you have a low-pass filter
going to the + op-amp input.  At low frequencies
the overall gain is unity (+2 from this input, -1
from the inverting input connected to the same
signal).  At high frequencies the + input is
grounded so you have a simple inverter with a gain
of -1.  At intermediate frequencies you get a
phase shift.  You can adjust the phase by
adjusting  the RC on the + input.  (There is no
need for the R to match the inverting Rs.)

Note that this approach can do what you request,
for a single input frequency, but all the RCs need
to be re-adjusted if the frequency changes.

If you want a scheme that will work for any single
frequency, you can digitally generate the signals
with different phases.  The problem is that sound
cards typically have only stereo outputs.  (You
can use the signal generator in Daqarta if you
want to experiment with 2 channels... it's free.
Daqarta can actually generate 8 independent data
streams, but they still have to be combined down
to 2 output channels:  4 on the right and 4 on the
left.)

There are sound cards that have multiple outputs
(5.1, 7.1, etc) but typically these only have two
independent channels that you can generate
arbitrary signals with... they produce the other
outputs by processing and combining those two
signals.  High-end cards may have independent
channels, but it's hard to tell that from the
docs.  (Daqarta currently only handles 2 signal
outputs regardless, so you'd have to write your
own generating code for more than 2.)

If you are handy with microprocessors, the general
approach is to create a circular buffer that holds
one cycle of a sine wave.  To generate a
frequency, you output samples from that table.
(To generate twice that frequency, skip every
other sample, etc.  )  To generate different
phases, just change the starting point in the
table.  You need a microprocessor with 8 DACs for
this project.

If you need to use arbitrary input frequencies
from a single source, you might want to look into
phase locked loops.  If you can adjust the lock
phase in a frequency-independent manner (don't
know, haven't tried this), you can have a separate
PLL for each output.  But a better approach might
be to use a single PLL to generate a high multiple
of the input frequency that is fed to various
counters, whose outputs are combined via selected
resistors to create a stepped approximation of a
sine wave (which can be easily filtered).  To get
the different phases, you would use different
counter arrangements.  LOTS of parts to this
approach, however.

If you tell us what your overall application is,
we can probably come up with something simpler.

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!- Hide quoted text -

- Show quoted text -

Glad to see someone suggested the All-pass filter. This is a simple
way to go if you are only working with one frequency at a time... Of
course if you have more than one frequency you can't really define a
unique phase shift.

George

 

[Eeyore]

Glad to see someone suggested the All-pass filter. This is a simple
way to go if you are only working with one frequency at a time...

It is by far the nicest IMHO since it also has a flat frequency response IIRC. I've used one in a
spiral scan radar display where the deflection coils were driven by sine and cosine waveforms and the
ampltude was ramped so as to provide a natural r,theta display.

Of course if you have more than one frequency you can't really define a
unique phase shift.

Indeed.

Graham

 

[Eeyore]

---
Only in your lonely little only analog world...

BTW, how'd you like my little AB final from a few weeks ago?

You (and Kevin of "We amp designers" fame never commented on it, so I
guess it dragged your dicks in the dirt, eh?

Your idea of an amplifier is so crap it begs belief. My designs of amplifiers have sold tens of thousands
to satisfied customers.

Here is an example of the most recent range I worked on.
http://cgi.ebay.co.uk/Studiomaster-...ryZ68247QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

You will regularly find products I designed on ebay.

You ?

Graham

 

[Eeyore]

---
Your "designs", I'm sure, were nothing new.

Lifted straight out of the GE transistor manual most likely, or
"borrowed" from some other handy source.

You haven't a fucking clue you ignorant winder-up. Show me a GE design that delivered 0.0008% THD.

Never had a GE manual anyway. Plus most app note designs have obvious flaws that wouldn't survive in the pro-audio world.

Graham

 

[Eeyore]

BFD; just another audio amp.
---

How many 3.5kW low distortion audio power amps have you designed ?

Graham

 

[Phil Allison]

"John Fields

BTW, while that AX3500 might be a nice amp, it's not rated for 3500
watts, it's rated for 2600 watts, bridged, into a 4 ohm load.

** Errr - its 2900 watts actually.

Also, its THD is 0.02% with only a single channel driven to rated power
at 1kHz, hardly the 0.0008% you seemed to be implying it could get in an
earlier post.

** That was in relation to a bygone lateral mosfet amp

- ie not this one.

That power would be 355 watts into 8 ohms, 550 watts into 4 ohms or 725
watts into 2 ohms,

** Huh ????

The single channel figures are 710, 1100 and 1450 watts " per channel" .

These numbers simply double in bridge mode and with twice the load Z
applied.

so it seems there's a little specsmanship going on
there by not rating it with both channels running at the same time and
bridged.

** The specs say the direct opposite to that.

http://www.studiomaster.com/brochures/axb.pdf

** Not familiar with reading stereo power amp specs - are we ??



.... Phil

 

[Eeyore]

---
How about if you post a schematic of one of "your" designs that does?

Oh, wait a minute... you could post _anything_ and claim it was yours,
so never mind.

Whta's the fucking matter with you ? I can design from 'scratch'. That's the only way to get the above
results.

Graham

 

[Eeyore]

---
None; that's not what I do.

How many 2kW 40kHz ceramic beamforming transducers have you designed?

BTW, while that AX3500 might be a nice amp, it's not rated for 3500
watts, it's rated for 2600 watts, bridged, into a 4 ohm load.

P.B. fucked up the specs again by the sound of it.

Also, its THD is 0.02% with only a single channel driven to rated power
at 1kHz, hardly the 0.0008% you seemed to be implying it could get in an
earlier post.

That was an entirely different MOSFET amplifier I designed nearly 20 years
ago.

0.02 % is fine for SR/PA use which is its intended application.

That power would be 355 watts into 8 ohms, 550 watts into 4 ohms or 725
watts into 2 ohms, so it seems there's a little specsmanship going on
there by not rating it with both channels running at the same time and
bridged.

710W, 1100W and 1450W per channel. Those figures are per channel with both
channels driven ! That's P.B.'s lousy spec writing again not making it
obvious.

CLOT.

Graham

 

[Eeyore]

---
Show us something, then and explain it.

I post schematics, JT posts schematics, Larkin posts schematics, Ed
posts schematics, Jamie posts schematics, and so do a few other folks
whom I can't bring to mind right now.

I've told you before. The copyright belongs to my client. I intend to talk to them about this point
actually very soon and at least some of the schematics may become re-available for free download. I don't
think the company is doing themselves any favours by referring interested parties to a pay site to get
them.

You, on the other hand, talk the talk, but you don't walk the walk.

No, it's the ONLY way. With what I've learned in the past few decades I wonder what figures I could get
now. I used MathCad to help model that design btw. Running under DOS !

Graham

 

[Jamie]

John Fields wrote:




I've told you before. The copyright belongs to my client. I intend to talk to them about this point
actually very soon and at least some of the schematics may become re-available for free download. I don't
think the company is doing themselves any favours by referring interested parties to a pay site to get
them.





No, it's the ONLY way. With what I've learned in the past few decades I wonder what figures I could get
now. I used MathCad to help model that design btw. Running under DOS !

Graham

Ha, Ancient software. Much like the ancient designs from an ancient
proclaimed, engineer.


http://webpages.charter.net/jamie_5"

 

[Phil Allison]

"John Fields"
"Phil Allison"

** No reply noted - wanker.




** There was none to miss - asshole.

You entirely mis-interpreted the power specs.




...... Phil

 

[Phil Allison]

"Eeysore"

I've told you before. The copyright belongs to my client.

** And I and others have told YOU before -

There is ** NO ** copyright infringement in posting an amplifier schem on
ABSE for folk to peruse and analyse.

No-one is asking you to " publish " it on a website.

Comes under the " fair usage" exclusion rules which includes private study,
writing reviews and criticism and other non profit uses.

Put up or shut up - you whining bullshit artist.


...... Phil

 

[Eeyore]

Ha, Ancient software. Much like the ancient designs from an ancient
proclaimed, engineer.

It was totally state of the art then. It proved invaluable on another project too. That shows how far ahead of
the pack I was. Of course I have a windows version now.

Graham

 

[Eeyore]

"Eeysore"


** And I and others have told YOU before -

There is ** NO ** copyright infringement in posting an amplifier schem on
ABSE for folk to peruse and analyse.

I prefer to clear it with the client first, not least because I believe the info
SHOULD be freely available to all who need it like their customers wishing to
service their kit, not just those on Usenet.

And a.b.s.e is no longer available to many US users of Usenet too. It hardly
addresses the issue adequately.

Graham

 

[Phil Allison]

"Eeysore Illiterate WANKER"

I prefer to clear it with the client first, not least because I believe
the info
SHOULD be freely available to all who need it like their customers wishing
to
service their kit, not just those on Usenet.

** Putting back the bits that were maliciously snipped:

*** No-one is asking you to " publish " it on a website. ****

There is NOTHING to " clear" - you whining bullshit artist.

And a.b.s.e is no longer available to many US users of Usenet too. It
hardly
addresses the issue adequately.

** As I have pointed out many times -

all ABSE pics are available here a day or so after appearing on the group.

http://www.usenet-replayer.com/groups/alt.binaries.schematics.electronic.html


** Put up or shut up - you whining bullshit artist.



....... Phil

 

[Phil Allison]

John Fields"

"Phil Allison"

** LOL - anything instead of saying " I was wrong and dumb".

But, there's still the matter of specifying THD under various operating
conditions.

** Wot a ridiculous beat up.

They chose to specify it with only one channel operating at rated load,
when a more revealing spec would reflect what would happen with both
channels operating, full bore, into their rated loads, or bridged.

** Complete bollocks.

IMO, that's cheating since those modes of operation are available but
not accounted for, especially since their THD will certainly be worse
than that specified for the single channel case.

** Utter drivel.

Proves you know SFA about audio amplifiers.


...... Phil