Tube amplifier analysis
bob.jo...@gmail.com
I'm trying to understand the use of the amplifiers in some of the
schematics above.
http://www.schematicheaven.com/boogieamps/boogie_lonestar.pdf
In several of the amplifiers there are preamp sections that do not use
emitter degeneration but are configured as CC. V3B is one example. I'm
a bit unsure why a capacitor was not added across the emitter
resistor.
I've seen similar circuitry used for the input tube where no emitter
resistor was used at all such as the supro Amp or the silvertones with
no emitter degeneration at all.
From what I understand the "emitter degeneration" is actually used to
create a stable bias for the tubes essentially lifting the emitter up
a few volts which effectively lowers the gate a few volts. This allows
input singles with no DC have full swing instead of being clipped.
Even more confusing is the input stage into the power amplifiers. This
looks to be class B, i.e., push pull, with the input stage being a
cathode coupled paraphase amplifier. What I don't understand is how
the gate's are creating the 180 out of phase signals that are driving
the power stage.
Any thoughts on whats going on?
JK17PWGBDR
<bob.jones5...@gmail.com> wrote:
> http://www.schematicheaven.com/mesaboogie.htm
>
> I'm trying to understand the use of the amplifiers in some of the
> schematics above.
>
> http://www.schematicheaven.com/boogieamps/boogie_lonestar.pdf
>
> In several of the amplifiers there are preamp sections that do not use
> emitter degeneration but are configured as CC. V3B is one example. I'm
> a bit unsure why a capacitor was not added across the emitter
> resistor.
The resistor is used in this case as a negative feedback.
It has the effect of reducing the gain while keeping the
frequency response flat over a wider range.
>
> I've seen similar circuitry used for the input tube where no emitter
> resistor was used at all such as the supro Amp or the silvertones with
> no emitter degeneration at all.
>
> From what I understand the "emitter degeneration" is actually used to
> create a stable bias for the tubes essentially lifting the emitter up
> a few volts which effectively lowers the gate a few volts. This allows
> input singles with no DC have full swing instead of being clipped.
>
> Even more confusing is the input stage into the power amplifiers. This
> looks to be class B, i.e., push pull, with the input stage being a
> cathode coupled paraphase amplifier. What I don't understand is how
> the gate's are creating the 180 out of phase signals that are driving
> the power stage.
Note that there are two inputs to these stages.
One is feedback from the output and the other is the audio input
It is a little confusing from the way it is drawn but this is a
differential amplifier. Any signal fed into one side will appear at
both plates with a 180 deg phase shift.
The feedback input compensates for the transformer frequency
response and makes sure the gain is the same for both
phases going to the power stage.
christofire
"Bob.Jo...@gmail.com" <bob.jo...@gmail.com> wrote in message
news:94b464f3-2cd0-438b...@m11g2000yqh.googlegroups.com...
> http://www.schematicheaven.com/mesaboogie.htm
>
> I'm trying to understand the use of the amplifiers in some of the
> schematics above.
>
> http://www.schematicheaven.com/boogieamps/boogie_lonestar.pdf
>
> In several of the amplifiers there are preamp sections that do not use
> emitter degeneration but are configured as CC. V3B is one example. I'm
> a bit unsure why a capacitor was not added across the emitter
> resistor.
>
> I've seen similar circuitry used for the input tube where no emitter
> resistor was used at all such as the supro Amp or the silvertones with
> no emitter degeneration at all.
>
> From what I understand the "emitter degeneration" is actually used to
> create a stable bias for the tubes essentially lifting the emitter up
> a few volts which effectively lowers the gate a few volts. This allows
> input singles with no DC have full swing instead of being clipped.
>
Shunting the cathode/emitter resistor of a common cathode/emitter stage with
a capacitor doesn't change the static (i.e.. 'DC') working point but it
reduces the dynamic (i.e. 'AC') negative feedback within the stage, and this
is often done to increase the stage gain. V3B in the given example follows
the effects return input and its purpose is to bring the output of an effect
device up to the same level (i.e. AC voltage) as what was fed into V3A, so
the same overall gain is achieved with the effect in or out of circuit. The
signal output by the cathode-follower V3A can be attenuated by up to about
19 dB by the 'send level' pot (to avoid clipping in the outboard effect
device, which may have been designed to take a guitar-level signal). V3B
then needs to provide 'make up' gain of up to 19 dB. With its non-bypassed
cathode resistor, the stage will provide a voltage gain of about 12x or 21
dB which is then reduced somewhat by the resistors in series with the
'output' pot.
>
> Even more confusing is the input stage into the power amplifiers. This
> looks to be class B, i.e., push pull, with the input stage being a
> cathode coupled paraphase amplifier. What I don't understand is how
> the gate's are creating the 180 out of phase signals that are driving
> the power stage.
>
> Any thoughts on whats going on?
The cathode-coupled 'paraphase' phase splitter operates in the same way as a
long-tailed pair. The pair of triodes share a common cathode resistor so
when one triode is biased further into conduction, its increased cathode
current raises the voltage of both cathodes so the second triode is biased
further out of conduction (assuming its grid voltage doesn't change). The
given example is a bit more complicated because the 330 k grid-leak
resistors are connected to the 15 k + 100 R part of the common tail resistor
(probably to raise the static operating voltage of the whole stage), whilst
the 470 R part between the cathodes and the junction with the grid-leak
resistors is the part that will cause the long-tailed pair behaviour. The
signal to be phase-split is fed to the grid of one triode, two antiphase
signals appear at the pair of anodes to be passed to the push-pull output
valves, and the grid of the other triode can be connected to earth or used
to add another signal (with reversed phase relative to the grid of the
triode first mentioned). In the given example, a signal from the
loudspeaker output is fed to this other grid to provide output-stage
negative feedback.
Chris
Rich Grise
> cathode coupled paraphase amplifier. What I don't understand is how
> the gate's are creating the 180 out of phase signals that are driving
> the power stage.
>
> Any thoughts on whats going on?
THERE IS NO PHASE SHIFT!!!!!!!!!!!!!
There is merely a polarity inversion.
Admittedly, an inverted sine wave LOOKS EXACLTY THE SAME AS one that's
phase-delayed by 180 degrees, but THEY ARE NOT THE SAME. To shift the
phase, you need some reactance in the signal path. There is none here,
merely a POLARITY INVERSION.
I wish people could get this abstract thought through their concrete
heads.
Thanks,
Rich
John Larkin
wrote:
Nothing abstract at all: polarity inversion is 180 degree phase shift.
John
bob.jo...@gmail.com
I WISH YOU OMNIFICENTS WOULD LEAVE US IGNORANT MORTALS
ALONE!!!!!!!!!!!!
Charles
"Rich Grise" <rich...@example.net> wrote in message
news:pan.2009.07.09....@example.net...
> On Thu, 09 Jul 2009 11:38:08 -0700, Bob.Jo...@gmail.com wrote:
>
>> cathode coupled paraphase amplifier. What I don't understand is how
>> the gate's are creating the 180 out of phase signals that are driving
>> the power stage.
>>
>> Any thoughts on whats going on?
>
> THERE IS NO PHASE SHIFT!!!!!!!!!!!!!
>
> There is merely a polarity inversion.
>
> Admittedly, an inverted sine wave LOOKS EXACLTY THE SAME AS one that's
Set your oscilloscope for external triggering, and you might find that they
are not exactly the same. Or, take advantage of your dual-trace scope to
establish a phase reference. A 180 degree phase shifted waveform does not
look EXACTLY the same, when one knows what to look for and has a decent
scope and knows how to use it.
Robert Baer
You have your terminology of tubes, bipolars and FETs all mixed up.
And what is this with the meaningless "with no DC have full swing" junk?
No voltage across a device means no *possibility* of any "swing".
Oh yea; that "Lonestar" reference is not a schematic so "cathode
coupled" is an ASS-u-ME-ption along with others...
greg
> Admittedly, an inverted sine wave LOOKS EXACLTY THE SAME AS one that's
> phase-delayed by 180 degrees, but THEY ARE NOT THE SAME.
Yes, they are. They're two different ways of talking
about the same thing -- one in the the time domain,
the other in the frequency domain.
You seem to have a misconception about what the
term "phase shift" means. It doesn't imply any kind
of time delay, nor any particular physical process.
It's purely a description of how the output waveform
is related to the input waveform. It says nothing about
how the relationship comes about.
--
Greg
Robert Baer
Sorry about that..having dial-up makes one impatient.
See V5A & V5B; they are configured as what is called as a
"long-tailed pair".
The unequal plate resistors compensate for the lower gain of the "B"
side WRT the "A" side.
Signal going into the grid of "A" drives it making a same-phase
signal on the cathode and an opposite (and larger) signal on its plate.
Assume that the GRID of "B" is constant; the voltage variations from
"A" drives "B" giving a same phase signal on its plate.
Those semi-equal (remember those plate resistors) signals then drive
the power output stage.
Too bad the transformer does not have screen taps...
Robert Baer
to 100KHz...
greg
> Set your oscilloscope for external triggering, and you might find that they
> are not exactly the same. Or, take advantage of your dual-trace scope to
> establish a phase reference. A 180 degree phase shifted waveform does not
> look EXACTLY the same, when one knows what to look for and has a decent
> scope and knows how to use it.
Reading between the lines, I'm guessing that what you have
in mind is comparing the output of an inverting stage with
that of some kind of reactive phase shifting network, when
you feed them both with a pure sine wave.
If they differ, all you've shown is that at least one of
them is not doing a perfect job of implementing a 180 degree
phase shift at that frequency without altering the signal
in any other way. Given the imperfections of real-world
circuitry, that's not very surprising.
This has no bearing on the issue at hand, which is a matter
of the definition terms. Inverting the signal and shifting
its phase by 180 degrees are the same thing *by definition*.
sin(x + 180deg) = -sin(x), for all x.
--
Greg
John Larkin
I'm not sure what you are suggesting. I didn't say anything about 135
degrees.
The thing you suggest isn't impossible, or even seriously difficult,
but it's not a polarity inverter.
John
Jim Thompson
It's almost trivial to make phase shifters that are quite good over an
octave. I do it all the time for use in image-reject mixers.
Over a wide range, it's been done, though not as easily... IIRC, see
papers by Darlington... yep the same guy (at Bell Labs, of course ;-)
...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine Sometimes I even put it in the food
Rich Grise
> On Thu, 09 Jul 2009 22:15:35 GMT, Rich Grise <rich...@example.net>
NO IT IS NOT! The two waveforms LOOK identical, but one has been phase
shifted, the other merely iverted.
Inversion does not shift phase.
Thanks,
Rich
Rich Grise
> On Jul 9, 5:15�pm, Rich Grise <richgr...@example.net> wrote:
>> On Thu, 09 Jul 2009 11:38:08 -0700, Bob.Jones5...@gmail.com wrote:
>> > cathode coupled paraphase amplifier. What I don't understand is how
>> > the gate's are creating the 180 out of phase signals that are driving
>> > the power stage.
>>
>> > Any thoughts on whats going on?
>>
>> THERE IS NO PHASE SHIFT!!!!!!!!!!!!!
>>
>> There is merely a polarity inversion.
>>
>> Admittedly, an inverted sine wave LOOKS EXACLTY THE SAME AS one that's
>> phase-delayed by 180 degrees, but THEY ARE NOT THE SAME. To shift the
>> phase, you need some reactance in the signal path. There is none here,
>> merely a POLARITY INVERSION.
>>
>> I wish people could get this abstract thought through their concrete
>> heads.
>
> ALONE!!!!!!!!!!!!
What's an "omnificient"?
Thanks,
Rich
Rich Grise
Let's try this little demonstration with a non-sinusoidal wave, say
a pulse train:
_ _ _ _ _
_____| |_____| |_____| |_____| |_____| |___
Now look at it phase- shifted 180 degrees:
_ _ _ _ _ _
_| |_____| |_____| |_____| |_____| |_____| |___
Now look at it inverted:
_____ _____ _____ _____ _____ _____
|_| |_| |_| |_| |_|
See the difference?
Thanks,
Rich
John Larkin
Dave Platt
Rich Grise <rich...@example.net> wrote:
>> Nothing abstract at all: polarity inversion is 180 degree phase shift.
>>
>
>NO IT IS NOT! The two waveforms LOOK identical, but one has been phase
>shifted, the other merely iverted.
>
>Inversion does not shift phase.
In the case of a pure sine wave, inversion and a 180-degree phase shift
are precisely identical, mathematically and in practice. You cannot
distinguish them based solely on the signals themselves (although you
can look inside the "black box" and figure out whether the *mechanism*
was one of inversion or time delay / phase shift).
Mathematically, sin(x + pi) = -sin(x) - the former is a phase shift
and the latter an inversion.
For any repeating signal (i.e. composed of the sum of sines of
different frequencies), you can exactly invert the signal by
phase-shifting each frequency component by exactly 180 degrees at that
frequency.
You cannot exactly invert such a signal (in general) by shifting the
*whole* signal by a time equivalent to 180 degrees at its primary
component frequency. It will (in general) look different.
The same is true for non-repeating or irregular signals.
--
Dave Platt <dpl...@radagast.org> AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
Dave Platt
And, as you pointed out, that's not a sine wave. It's a sum of
different (harmonically-related) sines (assuming that it's a precisely
regular pulse train, as your drawing suggests).
In this case, inverting the signal shifts *each* of these component
sines by 180 degrees at its individual frequency.
What you describe as "phase-shifted 180 degrees" is only a 180-degree
phase shift at *one* frequency - that of the fundamental. It's quite
a bit more than 180 degrees at each of the other component
frequencies. As a result, the component sines don't sum up to an
inverted version of the original pulse train.
JosephKK
Sorry John, Rich is actually right on this one. Just consider a
moderately asymmetrical waveform.
JosephKK
wrote:
>On Thu, 09 Jul 2009 16:36:18 -0700, Bob.Jo...@gmail.com wrote:
>> On Jul 9, 5:15 pm, Rich Grise <richgr...@example.net> wrote:
>>> On Thu, 09 Jul 2009 11:38:08 -0700, Bob.Jones5...@gmail.com wrote:
>>> > cathode coupled paraphase amplifier. What I don't understand is how
>>> > the gate's are creating the 180 out of phase signals that are driving
>>> > the power stage.
>>>
>>> > Any thoughts on whats going on?
>>>
>>> THERE IS NO PHASE SHIFT!!!!!!!!!!!!!
>>>
>>> There is merely a polarity inversion.
>>>
>>> Admittedly, an inverted sine wave LOOKS EXACLTY THE SAME AS one that's
>>> phase-delayed by 180 degrees, but THEY ARE NOT THE SAME. To shift the
>>> phase, you need some reactance in the signal path. There is none here,
>>> merely a POLARITY INVERSION.
>>>
>>> I wish people could get this abstract thought through their concrete
>>> heads.
>>
>> I WISH YOU OMNIFICENTS WOULD LEAVE US IGNORANT MORTALS
>> ALONE!!!!!!!!!!!!
>
>What's an "omnificient"?
>
>Thanks,
>Rich
How dare you besmirch the onmificient OZ?
JosephKK
wrote:
Only for single frequencies. Just try that comparison for complex
waveforms.
BTW shifting the phase of each frequency and re-normalizing all the
respective amplitudes is doable. It makes interesting differences in
the sound though.
Tim Williams
constant phase shift and constant time delay.
Bonus points for anyone would can construct any arbitrary phase shift from a
180 degree phase shift. Hint: it's not linearly independent.
Tim
--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms
"JosephKK" <quiett...@yahoo.com> wrote in message
news:p8bg55db3js0g67nt...@4ax.com...
Robert Baer
Jim Thompson
<tmor...@charter.net> wrote:
>Wow, I'm amazed how many posters here don't recognize the difference between
>constant phase shift and constant time delay.
>
>Bonus points for anyone would can construct any arbitrary phase shift from a
>180 degree phase shift. Hint: it's not linearly independent.
>
>Tim
At a single fixed frequency? Trivial. Name your frequency and phase
shift.
Amusing side bar: Create a "filter" that has constant 50us delay for
all frequencies.
Tim Williams
message news:a46h55d0qgafaf9au...@4ax.com...
> > Bonus points for anyone would can construct any arbitrary phase shift
> > from a 180 degree phase shift. Hint: it's not linearly independent.
>
> shift.
I should be more specific: using ideal amplifiers, i.e. adders and
resistors. You aren't allowed reactives -- those are, presumably, already
in the phase shifter (if it "is" a phase shifter). General, so it has to be
independent of frequency.
Part 2: now do it with a 90 degree phase shifted signal (and its original).
Trivial.
> Amusing side bar: Create a "filter" that has constant 50us delay for
> all frequencies.
I believe they call an approximation of those, "spool of coax". ;-)
John Larkin
<rober...@localnet.com> wrote:
Williams' filter book has a section on allpass 90 degree active phase
shifters. It's not hard to do a wideband, unity-gain, 90 degree
shifter with RC networks and opamps. Ham radio operators do it all the
time for phasing-method SSB. Once you have a 90 degree shift, simple
scaling and summing can give any angle you like.
Digitally, use a Hilbert filter and, again, a bit of summing.
John
Jim Thompson
<tmor...@charter.net> wrote:
>"Jim Thompson" <To-Email-Use-Th...@My-Web-Site.com> wrote in
>message news:a46h55d0qgafaf9au...@4ax.com...
>> > Bonus points for anyone would can construct any arbitrary phase shift
>> > from a 180 degree phase shift. Hint: it's not linearly independent.
>>
>> At a single fixed frequency? Trivial. Name your frequency and phase
>> shift.
>
>I should be more specific: using ideal amplifiers, i.e. adders and
>resistors. You aren't allowed reactives -- those are, presumably, already
>in the phase shifter (if it "is" a phase shifter). General, so it has to be
>independent of frequency.
Without something to actually "phase shift" you obviously can't do it.
With reactances you can do almost anything. Trivial over about an
octave... growing massively if decades of range are needed.
>
>Part 2: now do it with a 90 degree phase shifted signal (and its original).
>Trivial.
Indeed... strict summations, though NOT a linear pot ;-)
Student exercise: sin(theta + phi) = A*sin(theta) + B*cos(theta)
Solve for A & B as a function of phi ;-)
>
>> Amusing side bar: Create a "filter" that has constant 50us delay for
>> all frequencies.
>
>I believe they call an approximation of those, "spool of coax". ;-)
>
>Tim
Actually quite easy to do for f < 1/tdelay
Tim Williams
>>> Amusing side bar: Create a "filter" that has constant 50us delay for
>>> all frequencies.
>>
>>I believe they call an approximation of those, "spool of coax". ;-)
>>
>>Tim
>
> Actually quite easy to do for f < 1/tdelay
Pffbt, that's hardly "all frequencies". At least coax (good coax) works up
to a few hundred MHz, given slope compensation (although I'm not sure about
the comp's corresponding delay).
For literally *all* frequencies, nothing beats free space. But you'd better
have an all-pass antenna.
If you mean "all frequencies of interest" (such as frequencies phase shifted
only a little), an RC is probably a good enough approximation. 50us means f
<< 20kHz though, not very much bandwidth nor a very interesting delay.
A very nice digital delay can be constructed with current sources, cap
(i.e., a slew rate limited stage) and schmitt trigger, as long as minimum
pulse width is longer than the delay.
Jim Thompson
<tmor...@charter.net> wrote:
>"Jim Thompson" <To-Email-Use-Th...@My-Web-Site.com> wrote in
>message news:5cbh55tgtiamt998p...@4ax.com...
>>>> Amusing side bar: Create a "filter" that has constant 50us delay for
>>>> all frequencies.
>>>
>>>I believe they call an approximation of those, "spool of coax". ;-)
>>>
>>>Tim
>>
>> Actually quite easy to do for f < 1/tdelay
>
>Pffbt, that's hardly "all frequencies".
Putting on professor cap: Make that "all frequencies of interest" ;-)
>At least coax (good coax) works up
>to a few hundred MHz, given slope compensation (although I'm not sure about
>the comp's corresponding delay).
How many feet of coax for 20us ?:-)
I used the 20us example because I actually built (many ages ago) a
"pop" filter for records that delayed everything (audio) by 20us so I
could look for the spike and analog-switch it out ;-)
>
>For literally *all* frequencies, nothing beats free space. But you'd better
>have an all-pass antenna.
>
>If you mean "all frequencies of interest" (such as frequencies phase shifted
>only a little), an RC is probably a good enough approximation. 50us means f
><< 20kHz though, not very much bandwidth nor a very interesting delay.
>
>A very nice digital delay can be constructed with current sources, cap
>(i.e., a slew rate limited stage) and schmitt trigger, as long as minimum
>pulse width is longer than the delay.
>
>Tim
I can remember using TTL delay devices that had spiral wound coax
inside to emulate _very_ long chunks of coax.
In fact the MIT labs had such coax so that delay and interference
could be viewed with a crap scope (~1960).
John Larkin
Now we're debating definitions, specifically the definition of "phase"
for a non-sinusoidal waveform. It's like arguing whether a mixed
voltage is "AC" or "DC"
If you build a black box that applies a 180 degree phase shift to any
sine wave, it will invert any waveform.
Rich is defining 180 degree phase shift to be half-period time delay.
In our shop, we'd refer to that as "delayed by 180 degrees" where "180
degrees" is understood to be a measure of time, half the period of the
waveform; that's unambiguous. No linear box can do that for a general
waveform; you'd need an adaptive delay line.
Consider running Rich's pulse waveform through an all-pass network
that phase-shifts anything by 90 degrees; the result will look a lot
differerent from a 1/4 period delay line.
John
John Larkin
<tmor...@charter.net> wrote:
>"Jim Thompson" <To-Email-Use-Th...@My-Web-Site.com> wrote in
>message news:5cbh55tgtiamt998p...@4ax.com...
>>>> Amusing side bar: Create a "filter" that has constant 50us delay for
>>>> all frequencies.
>>>
>>>I believe they call an approximation of those, "spool of coax". ;-)
>>>
>>>Tim
>>
>> Actually quite easy to do for f < 1/tdelay
>
>Pffbt, that's hardly "all frequencies". At least coax (good coax) works up
>to a few hundred MHz, given slope compensation (although I'm not sure about
>the comp's corresponding delay).
>
>For literally *all* frequencies, nothing beats free space. But you'd better
>have an all-pass antenna.
Single-mode fiberoptics. DC-to-GHz of bandwidth and attenuation of a
fraction of a dB per km.
John
greg
> On Fri, 10 Jul 2009 22:01:26 +1200, greg <gr...@cosc.canterbury.ac.nz>
> wrote:
>
> > sin(x + 180deg) = -sin(x), for all x.
>
> Only for single frequencies. Just try that comparison for complex
> waveforms.
Phase shift is a frequency-domain concept. When working
in the frequency domain, you treat each sinewave component
individually.
When one talks about a "180 degree phase shift" in relation
to a complex waveform, it's shorthand for saying that the
phase shift as a function of frequency is given by
phi(f) = 180deg, for all f
> BTW shifting the phase of each frequency and re-normalizing all the
> respective amplitudes is doable. It makes interesting differences in
> the sound though.
Only to the extent that the circuit you're using to do it
is imperfect. If you did it perfectly, it *would* sound the
same.
--
Greg
Phil Allison
"greg" <gr...@cosc.canterbury.ac.nz
> Phase shift is a frequency-domain concept.
** Patent nonsense.
It is absolutey a time domain phenomenon.
With a "phase shifted" wave - one easily notices that amplitude peaks and
zero crossings are no longer co-incident in TIME with the input wave.
> When one talks about a "180 degree phase shift" in relation
> to a complex waveform, it's shorthand for saying that ...
** ... the polarity has been inverted.
... Phil
John Larkin
wrote:
>JosephKK wrote:
>> On Fri, 10 Jul 2009 22:01:26 +1200, greg <gr...@cosc.canterbury.ac.nz>
>> wrote:
> >
>> > sin(x + 180deg) = -sin(x), for all x.
>>
>> Only for single frequencies. Just try that comparison for complex
>> waveforms.
>
>Phase shift is a frequency-domain concept. When working
>in the frequency domain, you treat each sinewave component
>individually.
>
>When one talks about a "180 degree phase shift" in relation
>to a complex waveform, it's shorthand for saying that the
>phase shift as a function of frequency is given by
>
> phi(f) = 180deg, for all f
If you separate a complex waveform into its individual frequency
components, and shift each one 180 degrees, and recombine, you've just
inverted the waveform.
>
>> BTW shifting the phase of each frequency and re-normalizing all the
>> respective amplitudes is doable. It makes interesting differences in
>> the sound though.
>
>Only to the extent that the circuit you're using to do it
>is imperfect. If you did it perfectly, it *would* sound the
>same.
An all-pass network will shift every frequency by any desired angle,
without changing amplitudes. I don't know if it would sound very
different.
John
Phil Allison
"greg" <gr...@cosc.canterbury.ac.nz>
** Beware - sheep shagger on the loose ....
> Rich Grise wrote:
>
>> Admittedly, an inverted sine wave LOOKS EXACLTY THE SAME AS one that's
>> phase-delayed by 180 degrees, but THEY ARE NOT THE SAME.
>
> Yes, they are.
** Fraid they are not.
With the former, when altering the input wave frequency the output wave
remains perfectly inverted.
With the latter, the amount of phase shift will vary and so too will the
amplitude in most cases.
>They're two different ways of talking
> about the same thing -- one in the the time domain,
> the other in the frequency domain.
** Fraid you have that hoplessly wrong too.
> You seem to have a misconception about what the
> term "phase shift" means. It doesn't imply any kind
> of time delay, nor any particular physical process.
** Such terms cannot be defind **out of context**.
Only a COMPLETE FOOL tries to do THAT !!!!
The term " polarity inversion " is the one that best used when speaking
about wide band signals rather than individual sine wave frequencies.
However, the phrase: " 180 degrees out of phase" has gone into the tech
lingo in many areas to mean EXACTY the same thing.
In any ** real context ** - there is rarely any confustion in meaning with
180 degree phase shifts caused by other means.
..... Phil
JosephKK
Yep. Now if only we had affordable end electronics that was good for
that.
JosephKK
However it does not change the phase of all frequencies by the same
amount. At least that is what the math and the example circuits show.
John Larkin
The lithium niobate modulators can be had for a kilobuck or so (less
on ebay) and a pin diode good for a couple of GHz is $20 or so. But
the modulator is nonlinear (light-out goes as sin^2 of voltage, as I
recall) and a tad tricky to drive. Direct-modulated lasers are usually
nasty.
FM or equivalent into a laser diode could get you to 100 MHz maybe,
cheap.
People sell these things as RF links, like for received signals from
an antenna on a tower, down to a receiver in a shack on the ground.
John
John Larkin
It's easy to make a network that shifts all frequencies, over many
decades of frequency, by 90 degrees, flat on amplitude. Just opamps
and RCs, cascaded allpass networks with staggered center frequencies.
Once you have 0 and 90, resistive mixing will make any other desired
angle.
John
Phil Allison
"John Larkin = a LIAR "
>
> It's easy to make a network that shifts all frequencies, over many
> decades of frequency, by 90 degrees, flat on amplitude. Just opamps
> and RCs, cascaded allpass networks with staggered center frequencies.
** It is not "easy" to make any such damn thing.
I doubt it is even thereticvally possible.
Cascasded APFs produce large phase shifts at the output - ie several
cycles.
> Once you have 0 and 90, resistive mixing will make any other desired
> angle.
** Lack if the former preclues the latter.
..... Phil
John Larkin
wrote:
>
>"John Larkin = a LIAR "
>>
>> It's easy to make a network that shifts all frequencies, over many
>> decades of frequency, by 90 degrees, flat on amplitude. Just opamps
>> and RCs, cascaded allpass networks with staggered center frequencies.
>
>
>** It is not "easy" to make any such damn thing.
>
> I doubt it is even thereticvally possible.
See Williams+Taylor's filter book, 3rd edition. Fig 7-22 is an allpass
that gives 90 degrees shift from 300 to 3K Hz, +-0.1 degrees. It uses
six opamps and 24 passives.
Now if you are telling us that you design audio electronics and don't
have a copy of this book, well, that's the most bizarre thing you're
ever posted here.
John
Jim Thompson
Why do you persist in giving Asinine Allison a forum?
...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
Only Jerks Need to Satisfy Their Woeful Egos by Feeding Trolls
Phil Allison
"John Larkin"
"Phil Allison"
>
>>"John Larkin = a LIAR "
>>>
>>> It's easy to make a network that shifts all frequencies, over many
>>> decades of frequency, by 90 degrees, flat on amplitude. Just opamps
>>> and RCs, cascaded allpass networks with staggered center frequencies.
>>
>>
>>** It is not "easy" to make any such damn thing.
>>
>> I doubt it is even thereticvally possible.
>
> See Williams+Taylor's filter book, 3rd edition. Fig 7-22 is an allpass
> that gives 90 degrees shift from 300 to 3K Hz, +-0.1 degrees. It uses
> six opamps and 24 passives.
** Play fair you lying cut - post the schem.
All such filters I have studied or designed use TWO paths that differ by 90
degrees.
..... Phil
Glen Walpert
<To-Email-Use-Th...@My-Web-Site.com> wrote:
>On Mon, 13 Jul 2009 09:55:47 -0700, John Larkin
><jjla...@highNOTlandTHIStechnologyPART.com> wrote:
>
>>On Mon, 13 Jul 2009 18:21:45 +1000, "Phil Allison" <phi...@tpg.com.au>
>>wrote:
>>
>>>
>>>"John Larkin = a LIAR "
>>>>
>>>> It's easy to make a network that shifts all frequencies, over many
>>>> decades of frequency, by 90 degrees, flat on amplitude. Just opamps
>>>> and RCs, cascaded allpass networks with staggered center frequencies.
>>>
>>>
>>>** It is not "easy" to make any such damn thing.
>>>
>>> I doubt it is even thereticvally possible.
>>
>>See Williams+Taylor's filter book, 3rd edition. Fig 7-22 is an allpass
>>that gives 90 degrees shift from 300 to 3K Hz, +-0.1 degrees. It uses
>>six opamps and 24 passives.
>>
>>Now if you are telling us that you design audio electronics and don't
>>have a copy of this book, well, that's the most bizarre thing you're
>>ever posted here.
>>
>>John
>>
>
>Why do you persist in giving Asinine Allison a forum?
>
> ...Jim Thompson
And why do you persist in objecting to persons whose views and posting
styles differ from your own? I would have thought that someone such
as yourself, known to have had experience with autistic children,
would have a bit more understanding of and patience with those whose
experience/genetics/capabilities/perspective etc differ from your own,
for whatever reason.
My hat is off to John for engaging Mr. Allison in a constructive
rather than destructive manner.
>Only Jerks Need to Satisfy Their Woeful Egos by Feeding Trolls
And what sort of person needs to satisfy their woeful egos by blasting
everyone whose views, experience and posting styles differ from their
own? Oops, there I go again, following your example rather than Johns
:-).
...Glen Walpert
Phil Allison
"Glen Walpert"
** My god you are a fucking idiot.
John Larkin is a crazy and deliberate LIAR.
He has often bragged that he takes nothing HE posts on usenet seriously.
IOW he reserves the right to post any damn lie or use any dishoest trick he
feels like.
And he DOES !!
>>Why do you persist in giving Asinine Allison a forum?
>>
>> ...Jim Thompson
** Thompson is serously demented, raving looney.
Same kind of ASD fucked brain as Larkin, but much worse.
> And why do you persist in objecting to persons whose views and posting
> styles differ from your own? I would have thought that someone such
> as yourself, known to have had experience with autistic children,
** His own - right ??
> would have a bit more understanding of and patience with those whose
> experience/genetics/capabilities/perspective etc differ from your own,
> for whatever reason.
>
> My hat is off to John for engaging Mr. Allison in a constructive
> rather than destructive manner.
** The way Larkin " engages " with most others is entirely DESTRUCTIVE.
Cos Larkin is a congentiatal sociopath.
While YOU are a BLOODY IDIOT !
..... Phil
Jim Thompson
wrote:
Allison doesn't have autism, he has severe jerk-off disease.
GFY!
...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
Jim Thompson
Mooncalf ;-)
...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
John Larkin
wrote:
>
>"John Larkin"
> "Phil Allison"
>>
>>>"John Larkin = a LIAR "
>>>>
>>>> It's easy to make a network that shifts all frequencies, over many
>>>> decades of frequency, by 90 degrees, flat on amplitude. Just opamps
>>>> and RCs, cascaded allpass networks with staggered center frequencies.
>>>
>>>
>>>** It is not "easy" to make any such damn thing.
>>>
>>> I doubt it is even thereticvally possible.
>>
>> See Williams+Taylor's filter book, 3rd edition. Fig 7-22 is an allpass
>> that gives 90 degrees shift from 300 to 3K Hz, +-0.1 degrees. It uses
>> six opamps and 24 passives.
>
>** Play fair you lying cut - post the schem.
Buy the book. It's really worth having.
>All such filters I have studied or designed use TWO paths that differ by 90
>degrees.
>
Yes, they do.
I'm not a signals expert, but my impressions are that...
A true 90 degree phase shifter is non-causal, like an ideal lowpass
filter. Its transfer function can be defined, and it can be
approximated in real life, but the implementation must introduce time
delay to get around the causality (ie, predicting the future) dilemma.
You can make a 90 degree shifter by taking the Fourier transform of a
signal, swapping the real and imaginary components, and then reverse
transforming. That can be implemented with an FFT, again with time
delay to sort of prime the pump full of samples. The bandwidth will be
limited on the high end by the Nyquist criterion, and on the low end
by the number of samples used in the FFT.
In an FPGA, you can do a FIR implementation of a Hilbert 90 degree
phase shifter, with high/low frequency limits similar to the FFT idea,
and time delay like any FIR filter. I think the Xilinx software will
build optimized Hilbert filters for you, with some clever folding
tricks. The time delay is usually worked around by delaying the
original signal by an equal amount.
Some signal processing pros here can correct me or fill in details.
John
Phil Allison
"John Larkin = a FUCKING LIAR "
>>
>>>>> It's easy to make a network that shifts all frequencies, over many
>>>>> decades of frequency, by 90 degrees, flat on amplitude. Just opamps
>>>>> and RCs, cascaded allpass networks with staggered center frequencies.
>>>>> angle.
>>>>
>>>>
>>>>
>>>
>>> See Williams+Taylor's filter book, 3rd edition. Fig 7-22 is an allpass
>>> that gives 90 degrees shift from 300 to 3K Hz, +-0.1 degrees. It uses
>>> six opamps and 24 passives.
>>
>
>>All such filters I have studied or designed use TWO paths that differ by
>>90
>>degrees.
>>
>
> Yes, they do.
** So you admit to LYING - yet again.
What a fucking, septic PIG you are.
..... Phil
greg
> A true 90 degree phase shifter is non-causal, like an ideal lowpass
> filter. Its transfer function can be defined, and it can be
> approximated in real life, but the implementation must introduce time
> delay to get around the causality (ie, predicting the future) dilemma.
Do you have a reference? Googling on the concept of
non-causal filters only seems to turn up material
relating to digital filters. Does this apply only to
digital filters, or to analog filter circuits as well?
--
Greg
John Larkin
wrote:
You can google "Hilbert transform" and "ideal lowpass filter" for some
bits on causality. Both analog and digital filters are causal, because
they are real.
An ideal lowpass filter has an impulse response that rings before the
impulse hits - in fact the impulse response rings over all of time,
past and future - so it's impossible to build. An ideal Hilbert
90-degree phase shifter has a positive 1/t tail after the impulse and
a negative 1/t tail going backwards in time before the input, also
impossible in real life. So any real-life approximation has to add
delay; the better the approximation to the shape of the ideal impulse
response, the more you have to shift the impulse response to the right
to minimize chopping important stuff off the left-hand end.
http://www.nalanda.nitc.ac.in/nitcresources/ece/abhilash/course/hilbert.pdf
http://en.wikipedia.org/wiki/Low-pass_filter#Ideal_and_real_filters
http://ccrma.stanford.edu/~jos/sasp/Ideal_Lowpass_Filter.html
John
Phil Hobbs
> On Sat, 11 Jul 2009 03:04:45 -0700, Robert Baer
> <rober...@localnet.com> wrote:
>
>> John Larkin wrote:
>>> On Fri, 10 Jul 2009 02:56:20 -0700, Robert Baer
>>> <rober...@localnet.com> wrote:
>>>
>>>> John Larkin wrote:
>>>>> On Thu, 09 Jul 2009 22:15:35 GMT, Rich Grise <rich...@example.net>
>>>>>
>>>>>> On Thu, 09 Jul 2009 11:38:08 -0700, Bob.Jo...@gmail.com wrote:
>>>>>>
>>>>>>> cathode coupled paraphase amplifier. What I don't understand is how
>>>>>>> the gate's are creating the 180 out of phase signals that are driving
>>>>>>> the power stage.
>>>>>>>
>>>>>>> Any thoughts on whats going on?
>>>>>> THERE IS NO PHASE SHIFT!!!!!!!!!!!!!
>>>>>>
>>>>>> There is merely a polarity inversion.
>>>>>>
>>>>>> phase, you need some reactance in the signal path. There is none here,
>>>>>> merely a POLARITY INVERSION.
>>>>>>
>>>>>> I wish people could get this abstract thought through their concrete
>>>>>> heads.
>>>>>>
>>>>> Nothing abstract at all: polarity inversion is 180 degree phase shift.
>>>>>
>>>>>
>>>> ...then build us a (say) 135 degree phase shifter good from (say) 10Hz
>>>> to 100KHz...
>>> I'm not sure what you are suggesting. I didn't say anything about 135
>>> degrees.
>>>
>>> The thing you suggest isn't impossible, or even seriously difficult,
>>> but it's not a polarity inverter.
>>>
>>>
>>> John
>>>
>> Well...put the design up in SED or confess that it ain't so easy..
>
> Williams' filter book has a section on allpass 90 degree active phase
> shifters. It's not hard to do a wideband, unity-gain, 90 degree
> shifter with RC networks and opamps. Ham radio operators do it all the
> time for phasing-method SSB. Once you have a 90 degree shift, simple
> scaling and summing can give any angle you like.
>
> Digitally, use a Hilbert filter and, again, a bit of summing.
>
> John
>
Most SSB 90-degree filters are really two filters whose phase difference
is 90 degrees. That's much easier to do over a multi-octave bandwidth.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net
Jim Thompson
Yep. I do that for image-reject mixers, simply for convenience (and
lack of trim).
Jim Thompson
I left out "differential".
christofire
"Phil Hobbs" <pcdhSpamM...@electrooptical.net> wrote in message
news:DLidnRawhsstDMPX...@supernews.com...
Not to forget Mike Gingell's polyphase network, re-invented by many since
1969, that makes a good job of it and avoids the need for cascaded active
elements.
ftp://ftp.vnet.net/pub/users/gingell/polyphas/
ftp://ftp.vnet.net/pub/users/gingell/polyphas/UK69_1.pdf
Chris
John Larkin
I think that cleverly takes out, for free, the delay inherent in
trying to create a real version of a non-causal filter. A 90 degree
shifter would need a pure delay line alongside it to line things up.
Inside an FPGA, doing a FIR Hilbert phase shifter, I think you can use
the same folded data delay line to tap off the FIR coefficients and to
delay the original signal. That could be handy for AC power
calculations.
John
Phil Hobbs
Cheers
Phil
George Herold
> "Phil Hobbs" <pcdhSpamMeSensel...@electrooptical.net> wrote in message
>
> news:DLidnRawhsstDMPX...@supernews.com...
>
>
>
>
>
> > John Larkin wrote:
> >> On Sat, 11 Jul 2009 03:04:45 -0700, Robert Baer
> >> <robertb...@localnet.com> wrote:
>
> >>> John Larkin wrote:
> >>>> On Fri, 10 Jul 2009 02:56:20 -0700, Robert Baer
> >>>> <robertb...@localnet.com> wrote:
>
> >>>>> John Larkin wrote:
> >>>>>> wrote:
>
> - Show quoted text -
This looks like the 'phase sequence filter' from AoE (2nd ed. pg
295).
George H.
John Larkin
Yes, it's intimidating. It's probably more sensible to do an IIR
simulation of the analog all-pass thing, or a tracking PLL and a
clocked delay line if there's just one frequency involved.
We need FPGAs with 1000x the resources of what we can afford today.
John
Phil Hobbs
It might be simpler to FFT, chop off the negative frequencies, and
double the positive ones.
Cheers
Phil Hobbs
Phil Hobbs
explicit. The above procedure will get you the analytic signal, i.e.
the signal plus j times its Hilbert transform. The actual Hilbert
transform deletes the DC and multiplies positive frequency components by
-j and negative frequency ones by j (depending on your sign
convention). Once you have the analytic signal, it's two real
multiplications and an add to get any phase shift you like.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
christofire
"George Herold" <gghe...@gmail.com> wrote in message
news:6b1d90e1-6618-470d...@s31g2000yqs.googlegroups.com...
On Jul 16, 10:07 am, "christofire" <christof...@btinternet.com> wrote:
-- snip --
> Not to forget Mike Gingell's polyphase network, re-invented by many since
> 1969, that makes a good job of it and avoids the need for cascaded active
> elements.
>
> ftp://ftp.vnet.net/pub/users/gingell/polyphas/ftp://ftp.vnet.net/pub/users/gingell/polyphas/UK69_1.pdf
>
> Chris- Hide quoted text -
>
> - Show quoted text -
This looks like the 'phase sequence filter' from AoE (2nd ed. pg
295).
George H.
Yes, they're the same arrangement. Does AoE give any credit to M. Gingell?
The same polyphase network also appears to be ascribed to HA5WH by the ARRL:
http://fermi.la.asu.edu/w9cf/articles/phase/node4.html
Chris
George Herold
> "George Herold" <ggher...@gmail.com> wrote in message
>
> news:6b1d90e1-6618-470d...@s31g2000yqs.googlegroups.com...
> On Jul 16, 10:07 am, "christofire" <christof...@btinternet.com> wrote:
>
> -- snip --
>
> > Not to forget Mike Gingell's polyphase network, re-invented by many since
> > 1969, that makes a good job of it and avoids the need for cascaded active
> > elements.
>
>
> > Chris- Hide quoted text -
>
> > - Show quoted text -
>
> This looks like the 'phase sequence filter' from AoE (2nd ed. pg
> 295).
>
> George H.
>
> Yes, they're the same arrangement. Does AoE give any credit to M. Gingell?
>
> The same polyphase network also appears to be ascribed to HA5WH by the ARRL:http://fermi.la.asu.edu/w9cf/articles/phase/node4.html
>
> Chris
No references in AoE that I ever found. I've used this circuit and
would have been happy to have the above ARRL link. I just mucked
around with a simulation until it gave a phase ripple I found
acceptable, then built and tested it. The first air wire prototype
had a nice tubular shape.
The problem with this circuit is there is no phase reference to the
input. (Well not quit true. There is certainly a relation between
output and input, but the phase twists around several times, going
from the lowest the highest frequencies, and you lose track after the
first 360.)
George H.
christofire
George H.
That's also true of the other analogue type that was being discussed here;
the one using two cascades of all-pass sections (e.g.
http://webpages.charter.net/wa1sov/technical/allpass/allpass.html). The
only application I can think of that combines the input signal with
something made from the output signals is the 'barber-pole' phasing effect
using a 1 Hz (or thereabouts) frequency shift, as used on DSotM and
elsewhere - is that what you were creating?
Chris
George Herold
> only application I can think of that combines the input signal with
> something made from the output signals is the 'barber-pole' phasing effect
> using a 1 Hz (or thereabouts) frequency shift, as used on DSotM and
> elsewhere - is that what you were creating?
>
>
> - Show quoted text -
Thanks for the link Chris, The all-pass network certainly uses a lot
of op-amps. I'm not sure what a DSotM is? But I used the phase
sequence filter as part of the phase shifter in this lock-in.
http://www.teachspin.com/instruments/signal_processor/index.shtml
Only good from 3 Hz to 3kHz.
George H.
christofire
George H.
Thanks for your link; interesting.
Dark Side of the Moon: 19th para in
http://utopia.knoware.nl/users/ptr/pfloyd/interview/dark4.html. It was a
frequency translator (shifter) with the 'local oscillator' set to about 1
Hz, and the output (shifted) signal mixed with the input signal. Some liken
the effect to that of a Leslie speaker (e.g.
http://www.iua.upf.es/dafx98/papers/WAR19.PS which used to be available as a
.pdf), but the latter is a lot more complicated. Harald Bode had at least
one patent for a 'barber pole' phasing scheme using the same principle and
some have drawn comparisons with the so-called 'Shepard Tone'
(http://en.wikipedia.org/wiki/Shepard_tone). One regular correspondent to
this NG is on record as saying 'Some foul noises are possible if you mix the
original and the shifted sounds'
(http://www.tomshardware.co.uk/forum/page-42844_32_0.html) - and as the
editor of a popular British magazine has written: one man's ultimate guitar
tone is the next man's angle grinder!
As you say, a polyphase network of reasonable complexity is good for 3
octaves, such as the SSB speech band 300 Hz to 2.4 kHz or, at a stretch, up
to 4.8 kHz. Some claim to have achieved good sideband suppression even up to
9.6 kHz. The way forward nowadays must surely be DSP, wherein increased
complexity becomes little more than duplication, and a simple implementation
is described in http://www.csounds.com/manual/html/hilbert.html ... but that
makes me sound like a code writer.
Chris
George Herold
>
> Only good from 3 Hz to 3kHz.
>
> George H.
>
> Thanks for your link; interesting.
>
> frequency translator (shifter) with the 'local oscillator' set to about 1
> Hz, and the output (shifted) signal mixed with the input signal. Some liken
> .pdf), but the latter is a lot more complicated. Harald Bode had at least
> one patent for a 'barber pole' phasing scheme using the same principle and
> some have drawn comparisons with the so-called 'Shepard Tone'
> (http://en.wikipedia.org/wiki/Shepard_tone). One regular correspondent to
> this NG is on record as saying 'Some foul noises are possible if you mix the
> original and the shifted sounds'
> (http://www.tomshardware.co.uk/forum/page-42844_32_0.html) - and as the
> editor of a popular British magazine has written: one man's ultimate guitar
> tone is the next man's angle grinder!
>
> As you say, a polyphase network of reasonable complexity is good for 3
> octaves, such as the SSB speech band 300 Hz to 2.4 kHz or, at a stretch, up
> to 4.8 kHz. Some claim to have achieved good sideband suppression even up to
> 9.6 kHz. The way forward nowadays must surely be DSP, wherein increased
> complexity becomes little more than duplication, and a simple implementation
> makes me sound like a code writer.
>
>
> - Show quoted text -
Thanks again Chris, I'm afraid I'm not much of an audio guy. Though
lots of the circuits I build work in the audio range. I remeber
mentioning to a guitar playing friend that I was using a diode ring
modulator as part of a capacitance sensor. He started talking about
guitar effects and I had no idea what he was refering to. I was born
in '58 so DSotM is somting I know.. at the time I had no interest in
how it was made...still love'd it.
" > As you say, a polyphase network of reasonable complexity is good
for 3
> octaves, such as the SSB speech band 300 Hz to 2.4 kHz or, at a stretch, up
> to 4.8 kHz. Some claim to have achieved good sideband suppression even up to
> 9.6 kHz."
I must be more lucky than smart. I never tried to push anything in
the lockin design. Honestly it was my bosses idea and I never thought
it would be a big seller. (not the first time I've been wrong.) IIRC
I used eight stages of R/C's. I was more worried about the 3Hz part
of the spectrum at the time. The idea was to span both sides of
60Hz. I'm not sure how to measure sideband suppression, but I would
think that 30 Hz to 30kHz would be doable. I could reduce either the
C or the R. It's interesting that the circuit presents vastly
different impedances as a function of frequency to whatever is driving
it. I used good polypro capacitors.
George H.
JosephKK
Try this one general audio use:
Version 4
SHEET 1 1056 1048
WIRE 496 -448 368 -448
WIRE 368 -416 368 -448
WIRE 496 -416 496 -448
WIRE 208 -336 176 -336
WIRE 624 -336 560 -336
WIRE 800 -336 704 -336
WIRE 176 -272 -224 -272
WIRE 368 -272 368 -336
WIRE 368 -272 176 -272
WIRE 416 -272 368 -272
WIRE 688 -272 416 -272
WIRE 784 -272 688 -272
WIRE 560 -160 560 -336
WIRE -16 -144 -96 -144
WIRE 96 -144 96 -336
WIRE 96 -144 64 -144
WIRE 688 -128 688 -272
WIRE 176 -112 176 -272
WIRE 560 -112 560 -160
WIRE 656 -112 560 -112
WIRE 96 -96 96 -144
WIRE 144 -96 96 -96
WIRE 800 -96 800 -336
WIRE 800 -96 720 -96
WIRE 896 -96 800 -96
WIRE 976 -96 976 -144
WIRE 288 -80 288 -336
WIRE 288 -80 208 -80
WIRE 352 -80 352 -96
WIRE 352 -80 288 -80
WIRE 480 -80 480 -160
WIRE 480 -80 352 -80
WIRE 608 -80 560 -80
WIRE 656 -80 608 -80
WIRE 128 -64 64 -64
WIRE 144 -64 128 -64
WIRE 480 -64 480 -80
WIRE 560 -64 560 -80
WIRE -96 -32 -96 -144
WIRE -16 -32 -96 -32
WIRE 64 -32 64 -64
WIRE 976 -32 976 -96
WIRE 128 -16 128 -64
WIRE 176 -16 176 -48
WIRE 368 -16 176 -16
WIRE 480 16 480 -64
WIRE 496 16 480 16
WIRE 560 16 560 -64
WIRE 688 16 688 -64
WIRE 864 16 688 16
WIRE 608 48 608 -80
WIRE 608 48 560 48
WIRE -96 64 -96 -32
WIRE -16 64 -96 64
WIRE 64 64 64 -32
WIRE 64 64 48 64
WIRE 128 80 128 48
WIRE 976 96 976 48
WIRE 416 112 416 -272
WIRE 416 112 224 112
WIRE 560 144 560 112
WIRE 128 160 80 160
WIRE -352 176 -448 176
WIRE -96 176 -96 64
WIRE -96 176 -272 176
WIRE 80 256 80 240
WIRE 560 256 560 224
WIRE 832 256 768 256
WIRE -224 272 -224 -272
WIRE -224 272 -304 272
WIRE -304 288 -304 272
WIRE 256 288 176 288
WIRE -448 304 -448 176
WIRE -336 304 -448 304
WIRE 416 304 416 272
WIRE 416 304 400 304
WIRE -96 320 -96 176
WIRE -96 320 -272 320
WIRE 400 320 400 304
WIRE 512 320 400 320
WIRE 688 320 688 256
WIRE 688 320 592 320
WIRE 784 320 784 -272
WIRE 784 320 752 320
WIRE -336 336 -368 336
WIRE -96 336 -96 320
WIRE -32 336 -96 336
WIRE 96 336 96 288
WIRE 96 336 48 336
WIRE -448 352 -448 304
WIRE 224 352 224 112
WIRE 752 352 752 320
WIRE 96 368 96 336
WIRE 192 368 96 368
WIRE 688 368 688 320
WIRE 720 368 688 368
WIRE 336 384 336 288
WIRE 336 384 256 384
WIRE 400 384 400 320
WIRE 400 384 336 384
WIRE 832 384 832 256
WIRE 832 384 784 384
WIRE 896 384 832 384
WIRE 976 384 976 304
WIRE 192 400 176 400
WIRE 720 400 704 400
WIRE -304 416 -304 352
WIRE -176 416 -304 416
WIRE -96 416 -96 336
WIRE 0 416 -96 416
WIRE 400 416 400 384
WIRE 512 416 480 416
WIRE 624 416 592 416
WIRE 688 416 624 416
WIRE 704 416 704 400
WIRE 704 416 688 416
WIRE -448 464 -448 432
WIRE 688 464 688 416
WIRE 80 480 80 416
WIRE 144 480 80 480
WIRE 176 480 176 400
WIRE 176 480 144 480
WIRE 752 480 752 416
WIRE 864 480 864 16
WIRE 864 480 752 480
WIRE 976 480 976 384
WIRE 224 496 224 416
WIRE 288 496 224 496
WIRE -96 512 -96 416
WIRE 16 512 -96 512
WIRE 80 512 80 480
WIRE 144 512 144 480
WIRE 400 544 400 416
WIRE 624 544 624 416
WIRE 624 544 464 544
WIRE 688 560 688 528
WIRE -448 592 -448 544
WIRE -368 592 -368 336
WIRE -368 592 -448 592
WIRE 976 592 976 560
WIRE -448 624 -448 592
WIRE 32 640 16 640
WIRE 144 640 144 576
WIRE 144 640 112 640
WIRE 16 672 16 640
WIRE 688 672 688 640
WIRE 16 800 16 752
WIRE 688 800 688 752
WIRE -176 848 -176 416
WIRE 288 848 288 496
WIRE 288 848 -176 848
WIRE 368 848 368 -16
WIRE 368 848 288 848
WIRE 864 848 864 480
WIRE 864 848 368 848
WIRE 896 848 864 848
WIRE 896 880 896 848
WIRE 896 1008 896 960
FLAG -448 624 0
FLAG 80 256 0
FLAG 16 800 0
FLAG 560 256 0
FLAG 688 800 0
FLAG 976 96 0
FLAG 976 592 0
FLAG 896 1008 0
FLAG 496 -416 0
FLAG 976 -144 +45deg
FLAG 976 304 -45deg
FLAG 352 -96 +deg1
FLAG 416 272 -deg1
SYMBOL Opamps\\LT1028 -304 256 R0
SYMATTR InstName U1
SYMBOL Opamps\\LT1028 176 -144 R0
SYMATTR InstName U2
SYMBOL Opamps\\LT1028 688 -160 R0
SYMATTR InstName U3
SYMBOL Opamps\\LT1028 224 320 R0
SYMATTR InstName U4
SYMBOL Opamps\\LT1028 752 320 R0
SYMATTR InstName U5
SYMBOL voltage -448 448 R0
WINDOW 123 24 132 Left 0
WINDOW 39 24 160 Left 0
SYMATTR Value2 AC 1 0
SYMATTR SpiceLine Rser=100 Cpar=20p
SYMATTR InstName V1
SYMATTR Value SINE(0 1 20)
SYMBOL res -256 160 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R1
SYMATTR Value 10k
SYMBOL res 192 -352 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R2
SYMATTR Value 100k
SYMBOL res 304 -352 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R3
SYMATTR Value 5.6k
SYMBOL res 80 -160 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R4
SYMATTR Value 22k
SYMBOL res 80 -48 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R5
SYMATTR Value 56k
SYMBOL res 64 320 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R6
SYMATTR Value 22k
SYMBOL res 96 400 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R7
SYMATTR Value 39k
SYMBOL res 192 272 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R8
SYMATTR Value 100k
SYMBOL res 352 272 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R9
SYMATTR Value 5.6k
SYMBOL res 576 -176 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R10
SYMATTR Value 12k
SYMBOL res 576 -80 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R11
SYMATTR Value 47k
SYMBOL res 608 304 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R12
SYMATTR Value 12k
SYMBOL res 608 400 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R13
SYMATTR Value 3.9k
SYMBOL res 720 -352 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R14
SYMATTR Value 47k
SYMBOL res 784 240 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R15
SYMATTR Value 47k
SYMBOL res 112 64 R0
SYMATTR InstName R16
SYMATTR Value 47k
SYMBOL res 64 144 R0
SYMATTR InstName R17
SYMATTR Value 4.7k
SYMBOL res 0 656 R0
SYMATTR InstName R18
SYMATTR Value 2.0k
SYMBOL res 128 624 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R19
SYMATTR Value 33k
SYMBOL res 672 656 R0
SYMATTR InstName R20
SYMATTR Value 1.5k
SYMBOL res 672 544 R0
SYMATTR InstName R21
SYMATTR Value 22k
SYMBOL res 544 128 R0
SYMATTR InstName R22
SYMATTR Value 22k
SYMBOL cap 112 -16 R0
SYMATTR InstName C1
SYMATTR Value 1n
SYMBOL cap 544 48 R0
SYMATTR InstName C2
SYMATTR Value 100n
SYMBOL cap 128 512 R0
SYMATTR InstName C3
SYMATTR Value 27n
SYMBOL cap 672 464 R0
SYMATTR InstName C4
SYMATTR Value 470p
SYMBOL cap 560 0 R90
WINDOW 0 0 32 VBottom 0
WINDOW 3 32 32 VTop 0
SYMATTR InstName C5
SYMATTR Value 100n
SYMBOL cap 48 48 R90
WINDOW 0 0 32 VBottom 0
WINDOW 3 32 32 VTop 0
SYMATTR InstName C6
SYMATTR Value 1n
SYMBOL cap 80 496 R90
WINDOW 0 0 32 VBottom 0
WINDOW 3 32 32 VTop 0
SYMATTR InstName C7
SYMATTR Value 27n
SYMBOL res 496 400 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R23
SYMATTR Value 47k
SYMBOL cap 464 528 R90
WINDOW 0 0 32 VBottom 0
WINDOW 3 32 32 VTop 0
SYMATTR InstName C8
SYMATTR Value 470p
SYMBOL res 992 -112 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R24
SYMATTR Value 2k
SYMBOL res 992 368 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R25
SYMATTR Value 2k
SYMBOL res 960 -48 R0
SYMATTR InstName R26
SYMATTR Value 100k
SYMBOL res 960 464 R0
SYMATTR InstName R27
SYMATTR Value 100k
SYMBOL voltage 368 -320 R180
WINDOW 0 24 104 Left 0
WINDOW 3 24 16 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 24 76 Left 0
SYMATTR InstName V3
SYMATTR Value 15
SYMATTR SpiceLine Rser=0.1
SYMBOL voltage 896 976 R180
WINDOW 0 24 104 Left 0
WINDOW 3 24 16 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 24 -12 Left 0
SYMATTR InstName V2
SYMATTR Value 15
SYMATTR SpiceLine Rser=0.1
SYMBOL res -464 336 R0
SYMATTR InstName R28
SYMATTR Value 10k
TEXT -480 1032 Left 0 !.ac oct 4 20 20000
TEXT -480 928 Left 0 ;* Tuning parts (nominal) R3 (5.6k), R9 (5.6k),
R13 (3.9k), R17 (3.3k), R18 (2.0k), R20 (1.8K)
TEXT 272 -360 Left 0 ;*
TEXT 152 184 Left 0 ;*
TEXT 320 264 Left 0 ;*
TEXT 88 696 Left 0 ;*
TEXT 584 384 Left 0 ;*
TEXT 760 696 Left 0 ;*