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Fred Bloggs[_2_] Fred Bloggs[_2_] is offline
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Default another bizarre audio circuit

On Mar 2, 5:58*pm, John Larkin
wrote:
On Wed, 2 Mar 2011 14:55:18 -0800 (PST), Fred Bloggs





wrote:
On Mar 2, 4:33 pm, John Larkin
wrote:
On Wed, 2 Mar 2011 12:03:38 -0800 (PST), Fred Bloggs


wrote:
On Mar 2, 11:40 am, John Larkin
wrote:
I've always sort of liked the classic "GE" tape head/mic preamp
circuit:


ftp://jjlarkin.lmi.net/GEcircuit.jpg


but it occurred to me that it might also make a nice headphone amp....


ftp://jjlarkin.lmi.net/GE_headphone_amp.JPG


Audio tends to be nonsense, but at least the audio guys have fun
playing with circuits, whether they make a lot of sense or not.


John


Bizarre??? Just a standard buffered input CE with negative feedback DC
bias to stabilize the operating point against Vbe and reverse leakage
collector current change with temperature- a textbook circuit...


Which textbook?


John- Hide quoted text -


- Show quoted text -


Just about any textbook that goes into bias point sensitivity analysis
of transistor circuits- you remember the S- functions, mainly ICQ
stability. The big three were HFE, VBE, and ICBO. Then the rest of
your circuit is just ac-bypass and the shunt-series feedback for
signals. I've seen it dozens of times.


I bet you haven't seen the bipolar+mosfet version, with inductive
pullup, used as a power amp.

John- Hide quoted text -

- Show quoted text -


I don't see the MOSFET being all that much of a change. And as for the
inductor pull-up, this just doesn't make sense for low wattage high
impedance headphone loads. Your inductive reactance needs to be a good
few integer multiples of the load impedance, making these things
prohibitively large if not unobtainable for a headphone app- you would
use far less iron/ ferrite by boost switching your supply to
accommodate the output swing...guess that's why I've never seen the
inductive pullup here.
  #82   Report Post  
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John - KD5YI John - KD5YI is offline
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Default another bizarre audio circuit

On 3/3/2011 12:04 AM, John Larkin wrote:
On Wed, 02 Mar 2011 22:45:48 -0600, John -
wrote:

On 3/2/2011 10:24 PM, John Larkin wrote:
On Wed, 02 Mar 2011 22:06:41 -0600, John -
wrote:

On 3/2/2011 8:52 PM, John Larkin wrote:
On Wed, 02 Mar 2011 20:40:27 -0600, John -
wrote:

On 3/2/2011 8:32 PM, John Larkin wrote:
On Wed, 2 Mar 2011 17:59:58 -0800 (PST), Bill Sloman
wrote:

On Mar 3, 2:11 am, John Larkin
wrote:
On Wed, 02 Mar 2011 18:36:25 -0600, John Fields



wrote:
On Wed, 02 Mar 2011 08:40:42 -0800, John Larkin
wrote:

I've always sort of liked the classic "GE" tape head/mic preamp
circuit:

ftp://jjlarkin.lmi.net/GEcircuit.jpg

but it occurred to me that it might also make a nice headphone amp...

ftp://jjlarkin.lmi.net/GE_headphone_amp.JPG

Audio tends to be nonsense, but at least the audio guys have fun
playing with circuits, whether they make a lot of sense or not.

John

---
Even though you scorn and ridicule audio, there's nothing wrong with
anyone seeking perfection there, just as there's nothing wrong with
your search for perfection in the genre which pleases _you_ to pursue.
So, speaking of fun, why don't you do a complete design and assign
values to the circuit components and identify the semiconductors?

You're not playing the game. You are sitting in the henhouse, clucking
about the people who do.

He's not playing your game, which involves telling John Larkin how
cute his circuits are.

He's not designing circuits, which is what this newsgroup is about.

You aren't either. Both of you start to cluck and peck when people do
design circuits. No surprise.



Or is that legwork _we're_ supposed to do in order to flesh out your
divine revelation?

Chickenleg work!

It's half the story - a few component values make it a lot easier to
work out what a circuit is doing.

You can't look at a circuit this simple and see what it's doing? OK,
no surprise.

John

Well, I thought designing a circuit included supplying component values.
No?

I posted topologies. Values can be scaled to the application, but you
need a topology first. If I were actually going to build this, for
money, of course I'd have to define specs and then compute values.
That's just grunt work.

John

Not really. I have a few circuits I could throw out and claim that they
are topologies and you would not be able to use them without values.
Granted, mine are more complex than the one being discussed, but I'm
hoping to make a point.

John (not Larkin)


I think circuit topologies are fun to play with. Lots of textbooks
show, and discuss, circuits without explicit values. Once you have a
topology, then you can proceed to specs and component values.

If you think all circuits should be posted with values, post some.

John


You are correct, John. Now you have a topology. Please post the
component values.

Thanks,
John


Given i/o specs, the DC analysis is simple. But there are two AC
aspects that are sort of interesting: the lf response, and loop
stability. I'm sort of disappointed that nobody has commented on
either.

As I'm disappointed in how many people want to whine and cluck about
personalities, and avoid actually discussing electronics.

John


Okay, I put some values to it. It looks like a nice circuit, I admit.
Good gain, low distortion, reasonable input impedance. Mind you, I
didn't try to optimize it. I did notice that the feedback took higher
than expected resistance and I was a bit surprised that the emitter
capacitor of the output stage made the response do a camel hump at the
beginning if too high.

So, critique away. I might learn something.

Version 4
SHEET 1 880 680
WIRE 32 -496 -240 -496
WIRE 352 -496 32 -496
WIRE -240 -400 -240 -496
WIRE 32 -400 32 -496
WIRE 352 -400 352 -496
WIRE -240 -304 -240 -320
WIRE 352 -288 352 -320
WIRE 352 -288 160 -288
WIRE 528 -288 352 -288
WIRE 560 -288 528 -288
WIRE 352 -224 352 -288
WIRE 32 -176 32 -320
WIRE 288 -176 32 -176
WIRE 160 -96 160 -288
WIRE 160 32 160 -16
WIRE 32 80 32 -176
WIRE -320 128 -336 128
WIRE -272 128 -320 128
WIRE -112 128 -208 128
WIRE -32 128 -112 128
WIRE -336 208 -336 128
WIRE 32 208 32 176
WIRE 160 208 160 96
WIRE 160 208 32 208
WIRE -112 288 -112 128
WIRE 128 288 -112 288
WIRE 352 288 352 -128
WIRE 352 288 208 288
WIRE 448 288 352 288
WIRE -336 320 -336 288
WIRE 32 384 32 208
WIRE 352 384 352 288
WIRE 448 384 448 288
WIRE 32 480 32 464
WIRE 352 480 352 464
WIRE 448 480 448 448
FLAG -240 -304 0
FLAG 32 480 0
FLAG 352 480 0
FLAG 448 480 0
FLAG -336 320 0
FLAG -320 128 in
FLAG 528 -288 out
SYMBOL npn -32 80 R0
SYMATTR InstName Q1
SYMATTR Value 2N3904
SYMBOL npn 288 -224 R0
SYMATTR InstName Q2
SYMATTR Value 2N3904
SYMBOL cap -272 144 R270
WINDOW 0 32 32 VTop 0
WINDOW 3 0 32 VBottom 0
SYMATTR InstName C1
SYMATTR Value 10µ
SYMBOL res 112 304 R270
WINDOW 0 32 56 VTop 0
WINDOW 3 0 56 VBottom 0
SYMATTR InstName R1
SYMATTR Value 47k
SYMBOL res 16 368 R0
SYMATTR InstName R2
SYMATTR Value 1k
SYMBOL res 336 368 R0
SYMATTR InstName R3
SYMATTR Value 1.8k
SYMBOL cap 432 384 R0
SYMATTR InstName C2
SYMATTR Value 47µ
SYMBOL res 336 -416 R0
SYMATTR InstName R4
SYMATTR Value 3.3k
SYMBOL res 16 -416 R0
SYMATTR InstName R5
SYMATTR Value 4.7k
SYMBOL voltage -240 -416 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 9
SYMBOL res 144 -112 R0
SYMATTR InstName R6
SYMATTR Value 150k
SYMBOL cap 144 32 R0
SYMATTR InstName C3
SYMATTR Value .1µ
SYMBOL voltage -336 192 R0
WINDOW 123 24 132 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V2
SYMATTR Value SINE(0 5m 1000)
SYMATTR Value2 AC 1m
TEXT -370 504 Left 0 !.tran 0 510m 500m
TEXT -1072 8 Left 0 !;ac dec 100000 10 100k

  #83   Report Post  
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John Larkin John Larkin is offline
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Posts: 151
Default another bizarre audio circuit

On Thu, 03 Mar 2011 18:04:33 -0800, Chieftain of the Carpet Crawlers
wrote:

On Thu, 03 Mar 2011 08:59:38 -0800, John Larkin
wrote:

Stop whining and clucking about personalities


Stop with the retarded colloquialisms (or attempts at them). You
stupid ****. That is about as plain as it gets.

You show with nearly every post just how little a man you are. If you
even get that qualification.
Your personality is that of a circus flea.

Dance, mother****er.


The thing you guys have in common is that you suck at electronics, and
you know it. That pretty much explains everything.

John

  #84   Report Post  
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John Larkin John Larkin is offline
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Posts: 151
Default another bizarre audio circuit

On Thu, 03 Mar 2011 22:17:46 -0600, John - KD5YI
wrote:

On 3/3/2011 12:04 AM, John Larkin wrote:
On Wed, 02 Mar 2011 22:45:48 -0600, John -
wrote:

On 3/2/2011 10:24 PM, John Larkin wrote:
On Wed, 02 Mar 2011 22:06:41 -0600, John -
wrote:

On 3/2/2011 8:52 PM, John Larkin wrote:
On Wed, 02 Mar 2011 20:40:27 -0600, John -
wrote:

On 3/2/2011 8:32 PM, John Larkin wrote:
On Wed, 2 Mar 2011 17:59:58 -0800 (PST), Bill Sloman
wrote:

On Mar 3, 2:11 am, John Larkin
wrote:
On Wed, 02 Mar 2011 18:36:25 -0600, John Fields



wrote:
On Wed, 02 Mar 2011 08:40:42 -0800, John Larkin
wrote:

I've always sort of liked the classic "GE" tape head/mic preamp
circuit:

ftp://jjlarkin.lmi.net/GEcircuit.jpg

but it occurred to me that it might also make a nice headphone amp...

ftp://jjlarkin.lmi.net/GE_headphone_amp.JPG

Audio tends to be nonsense, but at least the audio guys have fun
playing with circuits, whether they make a lot of sense or not.

John

---
Even though you scorn and ridicule audio, there's nothing wrong with
anyone seeking perfection there, just as there's nothing wrong with
your search for perfection in the genre which pleases _you_ to pursue.
So, speaking of fun, why don't you do a complete design and assign
values to the circuit components and identify the semiconductors?

You're not playing the game. You are sitting in the henhouse, clucking
about the people who do.

He's not playing your game, which involves telling John Larkin how
cute his circuits are.

He's not designing circuits, which is what this newsgroup is about.

You aren't either. Both of you start to cluck and peck when people do
design circuits. No surprise.



Or is that legwork _we're_ supposed to do in order to flesh out your
divine revelation?

Chickenleg work!

It's half the story - a few component values make it a lot easier to
work out what a circuit is doing.

You can't look at a circuit this simple and see what it's doing? OK,
no surprise.

John

Well, I thought designing a circuit included supplying component values.
No?

I posted topologies. Values can be scaled to the application, but you
need a topology first. If I were actually going to build this, for
money, of course I'd have to define specs and then compute values.
That's just grunt work.

John

Not really. I have a few circuits I could throw out and claim that they
are topologies and you would not be able to use them without values.
Granted, mine are more complex than the one being discussed, but I'm
hoping to make a point.

John (not Larkin)


I think circuit topologies are fun to play with. Lots of textbooks
show, and discuss, circuits without explicit values. Once you have a
topology, then you can proceed to specs and component values.

If you think all circuits should be posted with values, post some.

John

You are correct, John. Now you have a topology. Please post the
component values.

Thanks,
John


Given i/o specs, the DC analysis is simple. But there are two AC
aspects that are sort of interesting: the lf response, and loop
stability. I'm sort of disappointed that nobody has commented on
either.

As I'm disappointed in how many people want to whine and cluck about
personalities, and avoid actually discussing electronics.

John


Okay, I put some values to it. It looks like a nice circuit, I admit.
Good gain, low distortion, reasonable input impedance. Mind you, I
didn't try to optimize it. I did notice that the feedback took higher
than expected resistance and I was a bit surprised that the emitter
capacitor of the output stage made the response do a camel hump at the
beginning if too high.



Yeah, C3 gives the overall amp response a low frequency bump, and C1
and C2 each contribute a low frequency rolloff. They all have to be
balanced to make it flat. Probably eliminating C3 is a good idea, if
the DC biasing still works. When I used this as a tape head preamp,
the LF boost was an asset, part of the tape head response
equalization.

R2 could be a lot lower. The open-loop voltage gain of Q1 is just
R5/R2, which is only 5, which is pretty low... even lower when it's
loaded by Q2. Or, another way to look at it, R2 kills the
transconductance of Q1, and adds noise.

If you do my power amp version, with a mosfet for Q2 and an inductor
for R4, there's another LF rolloff and the loop stability situation is
horrifying.

John


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John Larkin John Larkin is offline
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Default another bizarre audio circuit

On Thu, 3 Mar 2011 19:08:38 -0800 (PST), George Herold
wrote:

On Mar 3, 6:49*pm, John Larkin
wrote:
On Thu, 3 Mar 2011 15:21:33 -0800 (PST), Bill Sloman





wrote:
On Mar 3, 4:12 pm, John Larkin
wrote:
On Thu, 3 Mar 2011 00:10:16 -0800 (PST), Bill Sloman


wrote:
On Mar 3, 3:32 am, John Larkin
wrote:
On Wed, 2 Mar 2011 17:59:58 -0800 (PST), Bill Sloman


wrote:
On Mar 3, 2:11 am, John Larkin
wrote:
On Wed, 02 Mar 2011 18:36:25 -0600, John Fields


wrote:
On Wed, 02 Mar 2011 08:40:42 -0800, John Larkin
wrote:


I've always sort of liked the classic "GE" tape head/mic preamp
circuit:


ftp://jjlarkin.lmi.net/GEcircuit.jpg


but it occurred to me that it might also make a nice headphone amp...


ftp://jjlarkin.lmi.net/GE_headphone_amp.JPG


Audio tends to be nonsense, but at least the audio guys have fun
playing with circuits, whether they make a lot of sense or not.


John


---
Even though you scorn and ridicule audio, there's nothing wrong with
anyone seeking perfection there, just as there's nothing wrong with
your search for perfection in the genre which pleases _you_ to pursue.
So, speaking of fun, why don't you do a complete design and assign
values to the circuit components and identify the semiconductors?


You're not playing the game. You are sitting in the henhouse, clucking
about the people who do.


He's not playing your game, which involves telling John Larkin how
cute his circuits are.


He's not designing circuits, which is what this newsgroup is about.


You aren't either. Both of you start to cluck and peck when people do
design circuits. No surprise.


Or is that legwork _we're_ supposed to do in order to flesh out your
divine revelation?


Chickenleg work!


It's half the story - a few component values make it a lot easier to
work out what a circuit is doing.


You can't look at a circuit this simple and see what it's doing? OK,
no surprise.


Without the component values, it does take a moment's thought, which
is wasted on a bizarre (if simple) circuit with few potential
applications.


Millions of the "GE" circuit have been used for decades. The mosfet
hybrid is a very reasonable headphone amp.


Post a circuit, doofus. You've forgotten how to do anything but whine.


You are the one who complains all the time. You may have personal
preferences about the nature of the threads that get started here, and
the responses that get posted, but they are only of interest to you.


You are welcome to demonstrate your preferences by choosing to get
involved with particular threads and in your particular reactions to
other responses, but your whining about the nature of those responses
doesn't make the group a more attractive or rewarding environment.


In the meantime, I'll post a circuit when I've got a circuit worth
posting. Posting a example - without comnponent values - of a circuit
that has been used in millions, for decades, doesn't strike me as a
profitable use of bandwidth, but that is a personal preference.


What I did was spin a signal-level bipolar circuit into a
bipolar-mosfet power amp of similar topology.

The resulting dynamics is very interesting. Well, not to you.

John- Hide quoted text -

- Show quoted text -


Yeah, I didn't get the inductor part. Do I have to spice it? Or does
it have to do with head phone dynamics.

Say, and what about using the postive rail of an opamp as an output?
I never heard of that.

George H.



Old trick. Here's a bipolar-swing version.

ftp://jjlarkin.lmi.net/Opamp_boost_2.JPG

A similar thing is sometimes done to boost the current of an LM317, by
using its input current to drive the base of a PNP "helper"
transistor.

I use a variant of this circuit as a current splitter in my NMR
gradient amps.

I can't spell, or type, either.

John



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John Larkin John Larkin is offline
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Posts: 151
Default another bizarre audio circuit

On Thu, 03 Mar 2011 16:04:06 -0800, John Larkin
wrote:

On Thu, 3 Mar 2011 14:42:40 -0800 (PST), "
wrote:

On 2 Mar., 17:40, John Larkin
wrote:
I've always sort of liked the classic "GE" tape head/mic preamp
circuit:

ftp://jjlarkin.lmi.net/GEcircuit.jpg

but it occurred to me that it might also make a nice headphone amp...

ftp://jjlarkin.lmi.net/GE_headphone_amp.JPG

Audio tends to be nonsense, but at least the audio guys have fun
playing with circuits, whether they make a lot of sense or not.

John


speaking of bizarre : http://tubetime.us/?p=85
I'm sure someone here will love it


-Lasse


Wild. Sort of a single-slope ADC and a PWM driver. I wonder what the
sensitivity is like.

I bet you do a similar thing with a single tiny-logic schmitt gate.
Vaguely a superregenerative idea, namely triggering along a slowly
decaying exponential.

John


Yeah, this might work:

ftp://jjlarkin.lmi.net/Schmitt_Radio.JPG


John



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Terry Newton Terry Newton is offline
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Posts: 1
Default another bizarre audio circuit

On Wed, 02 Mar 2011 08:40:42 -0800, John Larkin wrote:

I've always sort of liked the classic "GE" tape head/mic preamp
circuit:

ftp://jjlarkin.lmi.net/GEcircuit.jpg

but it occurred to me that it might also make a nice headphone amp...

ftp://jjlarkin.lmi.net/GE_headphone_amp.JPG


I plugged this into LTspice and with a bit of twiddling appears
to work well, at least under simulation. I used a supply V of 15V,
transistor input resistor (R1) = 100K, input capacitor (C1) = 1uF,
transistor emitter resistor (R2) = 3.3K, feedback resistor (R3) = 22K,
cap in series with feedback resistor (C3) = 10uF,
bypass capacitor (C2) = 2200uF (needs to be big or lose LF gain/damping)
output capacitor (C4) = 470uF (let it charge before connecting)
inductor size of 10 henries (for sim assuming perfect, 0 ohms)
transistor collector resistor (R4) = 3.6K but can vary,
mosfet source resistor (R5, parallel with C2) = 47 but can vary.
Transistor = whatever (2N5550 in sim), mosfet = IRL530.

These values optimize for medium output power (570mW) into 50 ohms
and reasonable power (around 300mW) into 32 ohms and 100 ohms but
with off-center clipping. R4 and R5 can be varied to deliver the
desired power into the desired load... some of the values I tried...

100 ohm load.. R4=22K R5=22 PDQ=1.5W PDR5=0.3W
Pout=730mW into 100, 370mW into 50, 220mW into 32
50 ohm load... R4=9.1K R5=22 PDQ=2.2W PDR5=0.9W
Pout=1000mW into 50, 660mW into 32, 530mW into 100
50 ohm load... R4=5.6K R5=33 PDQ=1.6W PDR5=1.1W
Pout=788mW into 50, 490mW into 32, 400mW into 100
50 ohm load... R4=3.6K R5=47 PDQ=1.2W PDR5=1.1W
Pout=570mW into 50, 330mW into 32, 290mW into 100
32 ohm load... R4=5.1K R5=22 PDQ=2.5W PDR5=1.7W
Pout=1180mW into 32, 760mW into 50, 380mW into 100
32 ohm load... R4=3.3K R5=33 PDQ=1.7W PDR5=1.7W
Pout=790mW into 32, 560mW into 50, 280mW into 100
32 ohm load... R4=2.2K R5=47 PDQ=1.2W PDR5=1.6W
Pout=500mW into 32, 400mW into 50, 200mW into 100

(PDQ is mosfet dissipation, PDR5 is R5 dissipation)

R5 sets the overall power level, then adjust R4 to achieve
balanced clipping.

Output impedance is fairly low, not much variance as load changes.
Gain is approximately R3/R2 plus a bit. Distortion increases as
R4 (and open loop gain) decreases but it appears rather "tuby".

A 10 henry inductor is probably overkill, anything 1H or more will
probably be fine, for a HP amp there's plently of overhead and the
negative feedback will mostly correct for deficiencies, smaller
inductors just have less output at 20hz. Could probably use the
secondary of an output transformer with the primary insulated..
but watch out for core saturation. Should have fairly low resistance,
preferably less than a few ohms (can tweak values to compensate).
Someone in the thread said large inductors are "unobtainium" but
that's BS, transformer windings ARE huge inductors, for this level
of power a winding of a power transformer will probably work.
For class A amps using an inductor or transformer output doubles
efficiency and halves the supply voltage needed for a given output.
It also presents a high impedance at audio frequencies so that only
the load determines the impedance (thus the gain) of the output stage.
It's possible to use a resistor load but won't perform as well.


Audio tends to be nonsense, but at least the audio guys have fun
playing with circuits, whether they make a lot of sense or not.

John


But this one does make sense. There's a reason this basic circuit
has been around about as long as transistors...

Terry
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Bill Sloman Bill Sloman is offline
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Default another bizarre audio circuit

On Mar 4, 4:43*am, Chieftain of the Carpet Crawlers
wrote:
On Thu, 3 Mar 2011 18:37:42 -0800 (PST), Bill Sloman



wrote:
On Mar 4, 3:31 am, Chieftain of the Carpet Crawlers
wrote:
On Thu, 3 Mar 2011 14:42:40 -0800 (PST), "


wrote:
On 2 Mar., 17:40, John Larkin
wrote:
I've always sort of liked the classic "GE" tape head/mic preamp
circuit:


ftp://jjlarkin.lmi.net/GEcircuit.jpg


but it occurred to me that it might also make a nice headphone amp....


ftp://jjlarkin.lmi.net/GE_headphone_amp.JPG


Audio tends to be nonsense, but at least the audio guys have fun
playing with circuits, whether they make a lot of sense or not.


John


speaking of bizarre :http://tubetime.us/?p=85
I'm sure someone here will love it


-Lasse


Pretty good stuff.


It will go way over Sloman's head.


Along with the hundred other things a boy can do with a 555.


So someone has used a 555 to make a less than impressive radio-
receiver. Why would anybody be interested, if they hadn't fixated on
the device early in their career and never moved on?


* Oh, sorry, oh guru.

* You are right, that is what 90% of the rest of the world has done. *Not
moved on.

* Or could it be that it is *you* that has the problem?


Not really. Most of the people who post here haven't used a 555 for
years. Not because they don't know about it or don't like it but
because the kind of problem that it was designed to solve started
being solved in other wau=ys around 1980.

* You are the one that is not impressive.


I don't impress me. I see no reason why I should impress you.

--
Bill Sloman, Nijmegen

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John Devereux John Devereux is offline
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Posts: 2
Default another bizarre audio circuit

Bill Sloman writes:

On Mar 4, 4:43Â*am, Chieftain of the Carpet Crawlers
wrote:


[...]

Â* You are the one that is not impressive.


I don't impress me. I see no reason why I should impress you.


Tempting to put that on my sig.

--

John Devereux
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asdf[_2_] asdf[_2_] is offline
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Posts: 2
Default another bizarre audio circuit

On Wed, 02 Mar 2011 08:40:42 -0800, John Larkin wrote:

I've always sort of liked the classic "GE" tape head/mic preamp circuit:

ftp://jjlarkin.lmi.net/GEcircuit.jpg

but it occurred to me that it might also make a nice headphone amp...

ftp://jjlarkin.lmi.net/GE_headphone_amp.JPG


Audio tends to be nonsense, but at least the audio guys have fun playing
with circuits, whether they make a lot of sense or not.

John



Ironically, it looks somewhat similar to the old style fuzz face guitar
effect.
http://geofex.com/Article_Folders/fuzzface/fftech.htm


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Chieftain of the Carpet Crawlers Chieftain of the Carpet Crawlers is offline
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Posts: 10
Default another bizarre audio circuit

On Fri, 4 Mar 2011 02:35:52 -0800 (PST), Bill Sloman
wrote:


Not really. Most of the people who post here haven't used a 555 for
years.



You do not know that, and you saying it does not make it true.

You are an idiot to think so.
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Chieftain of the Carpet Crawlers Chieftain of the Carpet Crawlers is offline
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Default another bizarre audio circuit

On Fri, 04 Mar 2011 10:55:15 +0000, John Devereux
wrote:

Bill Sloman writes:

On Mar 4, 4:43*am, Chieftain of the Carpet Crawlers
wrote:


[...]

* You are the one that is not impressive.


I don't impress me. I see no reason why I should impress you.


Tempting to put that on my sig.


Only if it is a collection of stupid remarks.
  #93   Report Post  
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John Fields John Fields is offline
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Posts: 75
Default another bizarre audio circuit

On Thu, 03 Mar 2011 15:55:19 -0800, John Larkin
wrote:

On Thu, 03 Mar 2011 14:44:58 -0600, John Fields
wrote:

On Thu, 03 Mar 2011 10:22:31 -0800, John Larkin
wrote:

On Thu, 03 Mar 2011 12:07:36 -0600, John Fields
wrote:


---
The truth _is_ you have less of an interest in discussing electronics
in a give-and-take kind of way than you do in exalting yourself, so I
prefer to generally opt out of any threads you infect.

---
JF

I didn't "infect" this thread, I started it.


---
Then it was diseased from the beginning.
---

So why have you posted so much cluckey blather here?


---
You call it "cluckey blather" in an attempt to belittle it, I call it
what it is: criticism.


Criticism would have some content.


---
It does, and the content accurately enumerates your foibles, which is
anathema to you since you've managed to convince yourself and are
trying to convince everyone else that you're perfect in every way.
---

You know, something having to do with the circuit.


---
There are no rules here, as you've proved by your gross abuse of the
newsgroup with your legion off-topic posts, and if I choose to not
comment on your circuit, that's my right.
---

All you've done is whine.


---
Not so.

What I've done is simply point out technical errors which you've made,
over the years, and then been forced to respond to the calumny you
invariably invoke in order to try to make your stance seem unsullied.
---

You refuse to discuss this circuit, then you attack me personally for
not doing give-and-take discussion of this circuit!


---
It's not an attack, it's an observation, and it's not about this
circuit in particular, it's about your fanatical need to be in
control.


Electronic design is all about control. Of signals.

But you probably meant some sort of personal control. How does posting
a circuit, and opening it for discussion, suggest control? I thought
discussing circuits is what s.e.d. is for.


---
Then why do you defy the group's charter by posting off-topic,
irrelevant nonsense?
---

You're just a crabby old git who won't discuss electronics.


---
With you, since all you're interested in is fostering your agenda, the
inflation of your ego.

However, with others I have little reticence to join in a discussion,
and often do.

For instance, I'll refer you to the

"Driving Triac Directly with 555 Output?", the

"Looking for cheap, simple PIR detector module" and the

"24-bit on tap at Apple?" threads.

---
JF
  #94   Report Post  
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John Larkin John Larkin is offline
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Posts: 151
Default another bizarre audio circuit

On Fri, 04 Mar 2011 06:31:40 -0600, John Fields
wrote:

On Thu, 03 Mar 2011 15:55:19 -0800, John Larkin
wrote:

On Thu, 03 Mar 2011 14:44:58 -0600, John Fields
wrote:

On Thu, 03 Mar 2011 10:22:31 -0800, John Larkin
wrote:

On Thu, 03 Mar 2011 12:07:36 -0600, John Fields
wrote:

---
The truth _is_ you have less of an interest in discussing electronics
in a give-and-take kind of way than you do in exalting yourself, so I
prefer to generally opt out of any threads you infect.

---
JF

I didn't "infect" this thread, I started it.

---
Then it was diseased from the beginning.
---

So why have you posted so much cluckey blather here?

---
You call it "cluckey blather" in an attempt to belittle it, I call it
what it is: criticism.


Criticism would have some content.


---
It does, and the content accurately enumerates your foibles, which is
anathema to you since you've managed to convince yourself and are
trying to convince everyone else that you're perfect in every way.
---

You know, something having to do with the circuit.


---
There are no rules here, as you've proved by your gross abuse of the
newsgroup with your legion off-topic posts, and if I choose to not
comment on your circuit, that's my right.
---

All you've done is whine.


---
Not so.

What I've done is simply point out technical errors which you've made,
over the years, and then been forced to respond to the calumny you
invariably invoke in order to try to make your stance seem unsullied.
---

You refuse to discuss this circuit, then you attack me personally for
not doing give-and-take discussion of this circuit!

---
It's not an attack, it's an observation, and it's not about this
circuit in particular, it's about your fanatical need to be in
control.


Electronic design is all about control. Of signals.

But you probably meant some sort of personal control. How does posting
a circuit, and opening it for discussion, suggest control? I thought
discussing circuits is what s.e.d. is for.


---
Then why do you defy the group's charter by posting off-topic,
irrelevant nonsense?
---

You're just a crabby old git who won't discuss electronics.


---
With you, since all you're interested in is fostering your agenda, the
inflation of your ego.


My agenda is, and always has been, to design electronics. My ego has
been tuned to further that end. Electronics design requires a
combination of arrogance (to believe you can do things other people
can't) and humility (to avoid the thousands of possible mistakes) and
compulsiveness (to get it all done, all right.) And, more than
anything else, brutal honesty. Not many people an manage all that, and
lots of other people don't like the people who can.

There's not many things more fun than doing this with other people who
know how. Especially since the whiteboard was invented.

John

  #95   Report Post  
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John Larkin John Larkin is offline
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Posts: 151
Default another bizarre audio circuit

On Fri, 04 Mar 2011 11:12:39 GMT, asdf wrote:

On Wed, 02 Mar 2011 08:40:42 -0800, John Larkin wrote:

I've always sort of liked the classic "GE" tape head/mic preamp circuit:

ftp://jjlarkin.lmi.net/GEcircuit.jpg

but it occurred to me that it might also make a nice headphone amp...

ftp://jjlarkin.lmi.net/GE_headphone_amp.JPG


Audio tends to be nonsense, but at least the audio guys have fun playing
with circuits, whether they make a lot of sense or not.

John



Ironically, it looks somewhat similar to the old style fuzz face guitar
effect.
http://geofex.com/Article_Folders/fuzzface/fftech.htm



Except that it makes distortion, and a headphone amp shouldn't!

John



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John Fields John Fields is offline
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Posts: 75
Default another bizarre audio circuit

On Fri, 04 Mar 2011 06:51:30 -0800, John Larkin
wrote:

On Fri, 04 Mar 2011 06:31:40 -0600, John Fields
wrote:

On Thu, 03 Mar 2011 15:55:19 -0800, John Larkin
wrote:

On Thu, 03 Mar 2011 14:44:58 -0600, John Fields
wrote:

On Thu, 03 Mar 2011 10:22:31 -0800, John Larkin
wrote:

On Thu, 03 Mar 2011 12:07:36 -0600, John Fields
wrote:

---
The truth _is_ you have less of an interest in discussing electronics
in a give-and-take kind of way than you do in exalting yourself, so I
prefer to generally opt out of any threads you infect.

---
JF

I didn't "infect" this thread, I started it.

---
Then it was diseased from the beginning.
---

So why have you posted so much cluckey blather here?

---
You call it "cluckey blather" in an attempt to belittle it, I call it
what it is: criticism.

Criticism would have some content.


---
It does, and the content accurately enumerates your foibles, which is
anathema to you since you've managed to convince yourself and are
trying to convince everyone else that you're perfect in every way.
---

You know, something having to do with the circuit.


---
There are no rules here, as you've proved by your gross abuse of the
newsgroup with your legion off-topic posts, and if I choose to not
comment on your circuit, that's my right.
---

All you've done is whine.


---
Not so.

What I've done is simply point out technical errors which you've made,
over the years, and then been forced to respond to the calumny you
invariably invoke in order to try to make your stance seem unsullied.
---

You refuse to discuss this circuit, then you attack me personally for
not doing give-and-take discussion of this circuit!

---
It's not an attack, it's an observation, and it's not about this
circuit in particular, it's about your fanatical need to be in
control.

Electronic design is all about control. Of signals.

But you probably meant some sort of personal control. How does posting
a circuit, and opening it for discussion, suggest control? I thought
discussing circuits is what s.e.d. is for.


---
Then why do you defy the group's charter by posting off-topic,
irrelevant nonsense?
---

You're just a crabby old git who won't discuss electronics.


---
With you, since all you're interested in is fostering your agenda, the
inflation of your ego.


My agenda is, and always has been, to design electronics. My ego has
been tuned to further that end. Electronics design requires a
combination of arrogance (to believe you can do things other people
can't) and humility (to avoid the thousands of possible mistakes) and
compulsiveness (to get it all done, all right.) And, more than
anything else, brutal honesty. Not many people an manage all that, and
lots of other people don't like the people who can.

There's not many things more fun than doing this with other people who
know how. Especially since the whiteboard was invented.

John


---
On the above, I'm not at odds with you except for the "brutal honesty"
part which, when you're found to be in error, all of a sudden doesn't
apply to you.

---
JF
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George Herold George Herold is offline
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Posts: 5
Default another bizarre audio circuit

On Mar 4, 12:43*am, John Larkin
wrote:
On Thu, 3 Mar 2011 19:08:38 -0800 (PST), George Herold





wrote:
On Mar 3, 6:49*pm, John Larkin
wrote:
On Thu, 3 Mar 2011 15:21:33 -0800 (PST), Bill Sloman


wrote:
On Mar 3, 4:12 pm, John Larkin
wrote:
On Thu, 3 Mar 2011 00:10:16 -0800 (PST), Bill Sloman


wrote:
On Mar 3, 3:32 am, John Larkin
wrote:
On Wed, 2 Mar 2011 17:59:58 -0800 (PST), Bill Sloman


wrote:
On Mar 3, 2:11 am, John Larkin
wrote:
On Wed, 02 Mar 2011 18:36:25 -0600, John Fields


wrote:
On Wed, 02 Mar 2011 08:40:42 -0800, John Larkin
wrote:


I've always sort of liked the classic "GE" tape head/mic preamp
circuit:


ftp://jjlarkin.lmi.net/GEcircuit.jpg


but it occurred to me that it might also make a nice headphone amp...


ftp://jjlarkin.lmi.net/GE_headphone_amp.JPG


Audio tends to be nonsense, but at least the audio guys have fun
playing with circuits, whether they make a lot of sense or not.


John


---
Even though you scorn and ridicule audio, there's nothing wrong with
anyone seeking perfection there, just as there's nothing wrong with
your search for perfection in the genre which pleases _you_ to pursue.
So, speaking of fun, why don't you do a complete design and assign
values to the circuit components and identify the semiconductors?


You're not playing the game. You are sitting in the henhouse, clucking
about the people who do.


He's not playing your game, which involves telling John Larkin how
cute his circuits are.


He's not designing circuits, which is what this newsgroup is about.


You aren't either. Both of you start to cluck and peck when people do
design circuits. No surprise.


Or is that legwork _we're_ supposed to do in order to flesh out your
divine revelation?


Chickenleg work!


It's half the story - a few component values make it a lot easier to
work out what a circuit is doing.


You can't look at a circuit this simple and see what it's doing? OK,
no surprise.


Without the component values, it does take a moment's thought, which
is wasted on a bizarre (if simple) circuit with few potential
applications.


Millions of the "GE" circuit have been used for decades. The mosfet
hybrid is a very reasonable headphone amp.


Post a circuit, doofus. You've forgotten how to do anything but whine.


You are the one who complains all the time. You may have personal
preferences about the nature of the threads that get started here, and
the responses that get posted, but they are only of interest to you.


You are welcome to demonstrate your preferences by choosing to get
involved with particular threads and in your particular reactions to
other responses, but your whining about the nature of those responses
doesn't make the group a more attractive or rewarding environment.


In the meantime, I'll post a circuit when I've got a circuit worth
posting. Posting a example - without comnponent values - of a circuit
that has been used in millions, for decades, doesn't strike me as a
profitable use of bandwidth, but that is a personal preference.


What I did was spin a signal-level bipolar circuit into a
bipolar-mosfet power amp of similar topology.


The resulting dynamics is very interesting. Well, not to you.


John- Hide quoted text -


- Show quoted text -


Yeah, I didn't get the inductor part. *Do I have to spice it? *Or does
it have to do with head phone dynamics.


Say, and what about using the postive rail of an opamp as an output?
I never heard of that.


George H.


Old trick. Here's a bipolar-swing version.

ftp://jjlarkin.lmi.net/Opamp_boost_2.JPG

A similar thing is sometimes done to boost the current of an LM317, by
using its input current to drive the base of a PNP "helper"
transistor.

I use a variant of this circuit as a current splitter in my NMR
gradient amps.

I can't spell, or type, either.

John- Hide quoted text -

- Show quoted text -


Intersesting thanks. Is there a reason not to take the feedback from
the output (transistor collectors) rather than the opamp itself?

George H.
  #98   Report Post  
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John Larkin John Larkin is offline
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Posts: 151
Default another bizarre audio circuit

On Fri, 4 Mar 2011 07:31:14 -0800 (PST), George Herold
wrote:

On Mar 4, 12:43*am, John Larkin
wrote:
On Thu, 3 Mar 2011 19:08:38 -0800 (PST), George Herold





wrote:
On Mar 3, 6:49*pm, John Larkin
wrote:
On Thu, 3 Mar 2011 15:21:33 -0800 (PST), Bill Sloman


wrote:
On Mar 3, 4:12 pm, John Larkin
wrote:
On Thu, 3 Mar 2011 00:10:16 -0800 (PST), Bill Sloman


wrote:
On Mar 3, 3:32 am, John Larkin
wrote:
On Wed, 2 Mar 2011 17:59:58 -0800 (PST), Bill Sloman


wrote:
On Mar 3, 2:11 am, John Larkin
wrote:
On Wed, 02 Mar 2011 18:36:25 -0600, John Fields


wrote:
On Wed, 02 Mar 2011 08:40:42 -0800, John Larkin
wrote:


I've always sort of liked the classic "GE" tape head/mic preamp
circuit:


ftp://jjlarkin.lmi.net/GEcircuit.jpg


but it occurred to me that it might also make a nice headphone amp...


ftp://jjlarkin.lmi.net/GE_headphone_amp.JPG


Audio tends to be nonsense, but at least the audio guys have fun
playing with circuits, whether they make a lot of sense or not.


John


---
Even though you scorn and ridicule audio, there's nothing wrong with
anyone seeking perfection there, just as there's nothing wrong with
your search for perfection in the genre which pleases _you_ to pursue.
So, speaking of fun, why don't you do a complete design and assign
values to the circuit components and identify the semiconductors?


You're not playing the game. You are sitting in the henhouse, clucking
about the people who do.


He's not playing your game, which involves telling John Larkin how
cute his circuits are.


He's not designing circuits, which is what this newsgroup is about.


You aren't either. Both of you start to cluck and peck when people do
design circuits. No surprise.


Or is that legwork _we're_ supposed to do in order to flesh out your
divine revelation?


Chickenleg work!


It's half the story - a few component values make it a lot easier to
work out what a circuit is doing.


You can't look at a circuit this simple and see what it's doing? OK,
no surprise.


Without the component values, it does take a moment's thought, which
is wasted on a bizarre (if simple) circuit with few potential
applications.


Millions of the "GE" circuit have been used for decades. The mosfet
hybrid is a very reasonable headphone amp.


Post a circuit, doofus. You've forgotten how to do anything but whine.


You are the one who complains all the time. You may have personal
preferences about the nature of the threads that get started here, and
the responses that get posted, but they are only of interest to you.


You are welcome to demonstrate your preferences by choosing to get
involved with particular threads and in your particular reactions to
other responses, but your whining about the nature of those responses
doesn't make the group a more attractive or rewarding environment.


In the meantime, I'll post a circuit when I've got a circuit worth
posting. Posting a example - without comnponent values - of a circuit
that has been used in millions, for decades, doesn't strike me as a
profitable use of bandwidth, but that is a personal preference.


What I did was spin a signal-level bipolar circuit into a
bipolar-mosfet power amp of similar topology.


The resulting dynamics is very interesting. Well, not to you.


John- Hide quoted text -


- Show quoted text -


Yeah, I didn't get the inductor part. *Do I have to spice it? *Or does
it have to do with head phone dynamics.


Say, and what about using the postive rail of an opamp as an output?
I never heard of that.


George H.


Old trick. Here's a bipolar-swing version.

ftp://jjlarkin.lmi.net/Opamp_boost_2.JPG

A similar thing is sometimes done to boost the current of an LM317, by
using its input current to drive the base of a PNP "helper"
transistor.

I use a variant of this circuit as a current splitter in my NMR
gradient amps.

I can't spell, or type, either.

John- Hide quoted text -

- Show quoted text -


Intersesting thanks. Is there a reason not to take the feedback from
the output (transistor collectors) rather than the opamp itself?

George H.


Depends on what you want to do. In my gradient amps, I want the
overall box to be a current source, so I don't use any voltage
feedback. The upper and lower boost transistors are replaced by
precision current mirrors, and I usually cascode the opamp supply
currents up into the mirrors, bacause the rail voltages tend to be
high.

As a boosted voltage amp, you'd generally want voltage feedback from
the final output. The feedback can go into the inputs of the opamp,
but I've seen cases where the feedback was applied to the *output* of
the opamp.

John

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Posts: 151
Default another bizarre audio circuit

On Fri, 04 Mar 2011 09:18:28 -0600, John Fields
wrote:

On Fri, 04 Mar 2011 06:51:30 -0800, John Larkin
wrote:

On Fri, 04 Mar 2011 06:31:40 -0600, John Fields
wrote:

On Thu, 03 Mar 2011 15:55:19 -0800, John Larkin
wrote:

On Thu, 03 Mar 2011 14:44:58 -0600, John Fields
wrote:

On Thu, 03 Mar 2011 10:22:31 -0800, John Larkin
wrote:

On Thu, 03 Mar 2011 12:07:36 -0600, John Fields
wrote:

---
The truth _is_ you have less of an interest in discussing electronics
in a give-and-take kind of way than you do in exalting yourself, so I
prefer to generally opt out of any threads you infect.

---
JF

I didn't "infect" this thread, I started it.

---
Then it was diseased from the beginning.
---

So why have you posted so much cluckey blather here?

---
You call it "cluckey blather" in an attempt to belittle it, I call it
what it is: criticism.

Criticism would have some content.

---
It does, and the content accurately enumerates your foibles, which is
anathema to you since you've managed to convince yourself and are
trying to convince everyone else that you're perfect in every way.
---

You know, something having to do with the circuit.

---
There are no rules here, as you've proved by your gross abuse of the
newsgroup with your legion off-topic posts, and if I choose to not
comment on your circuit, that's my right.
---

All you've done is whine.

---
Not so.

What I've done is simply point out technical errors which you've made,
over the years, and then been forced to respond to the calumny you
invariably invoke in order to try to make your stance seem unsullied.
---

You refuse to discuss this circuit, then you attack me personally for
not doing give-and-take discussion of this circuit!

---
It's not an attack, it's an observation, and it's not about this
circuit in particular, it's about your fanatical need to be in
control.

Electronic design is all about control. Of signals.

But you probably meant some sort of personal control. How does posting
a circuit, and opening it for discussion, suggest control? I thought
discussing circuits is what s.e.d. is for.

---
Then why do you defy the group's charter by posting off-topic,
irrelevant nonsense?
---

You're just a crabby old git who won't discuss electronics.

---
With you, since all you're interested in is fostering your agenda, the
inflation of your ego.


My agenda is, and always has been, to design electronics. My ego has
been tuned to further that end. Electronics design requires a
combination of arrogance (to believe you can do things other people
can't) and humility (to avoid the thousands of possible mistakes) and
compulsiveness (to get it all done, all right.) And, more than
anything else, brutal honesty. Not many people an manage all that, and
lots of other people don't like the people who can.

There's not many things more fun than doing this with other people who
know how. Especially since the whiteboard was invented.

John


---
On the above, I'm not at odds with you except for the "brutal honesty"
part which, when you're found to be in error, all of a sudden doesn't
apply to you.

---
JF


I make mistakes all the time, and a lot of my ideas get paved over by
somebody else's ideas. I work with some *very* smart people who, in
their areas, know a lot more than I do. That's part of the fun of
playing with ideas.

But if you want to argue over definitions, like whether something
that's unboundedly large can be referred to as "infinite", that's just
words, definitions, and doesn't matter. It certainly doesn't affect
the electronics. A latching relay does what it does.

John



  #100   Report Post  
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John Larkin John Larkin is offline
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Posts: 151
Default another bizarre audio circuit

On Thu, 3 Mar 2011 19:53:58 -0800 (PST), Fred Bloggs
wrote:

On Mar 2, 5:58*pm, John Larkin
wrote:
On Wed, 2 Mar 2011 14:55:18 -0800 (PST), Fred Bloggs





wrote:
On Mar 2, 4:33 pm, John Larkin
wrote:
On Wed, 2 Mar 2011 12:03:38 -0800 (PST), Fred Bloggs


wrote:
On Mar 2, 11:40 am, John Larkin
wrote:
I've always sort of liked the classic "GE" tape head/mic preamp
circuit:


ftp://jjlarkin.lmi.net/GEcircuit.jpg


but it occurred to me that it might also make a nice headphone amp...


ftp://jjlarkin.lmi.net/GE_headphone_amp.JPG


Audio tends to be nonsense, but at least the audio guys have fun
playing with circuits, whether they make a lot of sense or not.


John


Bizarre??? Just a standard buffered input CE with negative feedback DC
bias to stabilize the operating point against Vbe and reverse leakage
collector current change with temperature- a textbook circuit...


Which textbook?


John- Hide quoted text -


- Show quoted text -


Just about any textbook that goes into bias point sensitivity analysis
of transistor circuits- you remember the S- functions, mainly ICQ
stability. The big three were HFE, VBE, and ICBO. Then the rest of
your circuit is just ac-bypass and the shunt-series feedback for
signals. I've seen it dozens of times.


I bet you haven't seen the bipolar+mosfet version, with inductive
pullup, used as a power amp.

John- Hide quoted text -

- Show quoted text -


I don't see the MOSFET being all that much of a change. And as for the
inductor pull-up, this just doesn't make sense for low wattage high
impedance headphone loads. Your inductive reactance needs to be a good
few integer multiples of the load impedance, making these things
prohibitively large if not unobtainable for a headphone app- you would
use far less iron/ ferrite by boost switching your supply to
accommodate the output swing...guess that's why I've never seen the
inductive pullup here.


Of course you haven't seen this circuit befo I just invented it.

But inductors were widely used as plate loads in the tube days. Tubes
were expensive and had low gains, so transformers and inductors were
sensible. Early transistor amps used lots of transformers, for the
same reasons.

John





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John Fields John Fields is offline
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Posts: 75
Default another bizarre audio circuit

On Fri, 04 Mar 2011 08:18:03 -0800, John Larkin
wrote:

On Fri, 04 Mar 2011 09:18:28 -0600, John Fields
wrote:


On the above, I'm not at odds with you except for the "brutal honesty"
part which, when you're found to be in error, all of a sudden doesn't
apply to you.

---
JF


I make mistakes all the time, and a lot of my ideas get paved over by
somebody else's ideas. I work with some *very* smart people who, in
their areas, know a lot more than I do. That's part of the fun of
playing with ideas.


---
Apples and oranges.

You're talking about who you are at work and I'm talking about who you
are here; obviously two different people.
---

But if you want to argue over definitions, like whether something
that's unboundedly large can be referred to as "infinite", that's just
words, definitions, and doesn't matter.


---
Total nonsense since if words and definitions didn't matter then
there'd be no purpose for language.

The thing is though, that it can't be unboundedly large as long as
there's something other than zero in the denominator, and if it takes
any power at all to switch it, you're stuck with less than infinite
gain.

Approaching infinity in the limit, but never quite able to get there.
---

It certainly doesn't affect
the electronics. A latching relay does what it does.

John


---
A rose, by any other name...

---
JF
  #102   Report Post  
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John Larkin John Larkin is offline
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Posts: 151
Default another bizarre audio circuit

On Fri, 04 Mar 2011 11:59:58 -0600, John Fields
wrote:

On Fri, 04 Mar 2011 08:18:03 -0800, John Larkin
wrote:

On Fri, 04 Mar 2011 09:18:28 -0600, John Fields
wrote:


On the above, I'm not at odds with you except for the "brutal honesty"
part which, when you're found to be in error, all of a sudden doesn't
apply to you.

---
JF


I make mistakes all the time, and a lot of my ideas get paved over by
somebody else's ideas. I work with some *very* smart people who, in
their areas, know a lot more than I do. That's part of the fun of
playing with ideas.


---
Apples and oranges.

You're talking about who you are at work and I'm talking about who you
are here; obviously two different people.


It's a newsgroup, not life.


---

But if you want to argue over definitions, like whether something
that's unboundedly large can be referred to as "infinite", that's just
words, definitions, and doesn't matter.


---
Total nonsense since if words and definitions didn't matter then
there'd be no purpose for language.

The thing is though, that it can't be unboundedly large as long as
there's something other than zero in the denominator, and if it takes
any power at all to switch it, you're stuck with less than infinite
gain.


What is infinity/1 ? You seem to be arguing that nothing can ever be
unboundedly large since any number can be divided by 1.


Approaching infinity in the limit, but never quite able to get there.


That's the way infinity tends to work. I was taught that infinity
isn't a number, it's a limit.

( Lim (1/x) as x0 ) infinity

which works well enough in engineering.

John

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Bill Sloman Bill Sloman is offline
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Posts: 12
Default another bizarre audio circuit

On Mar 4, 12:59*pm, Chieftain of the Carpet Crawlers
wrote:
On Fri, 4 Mar 2011 02:35:52 -0800 (PST), Bill Sloman

wrote:

Not really. Most of the people who post here haven't used a 555 for
years.


* You do not know that,


A similar thread to this a few years ago prompted a bunch of responses
saying exactly that, from people with a history in this group.

and you saying it does not make it true.


Obviously not. It does happen to be true, none-the-less.

* You are an idiot to think so.


You may think so.

--
Bill Sloman, Nijmegen
  #104   Report Post  
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John Fields John Fields is offline
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Posts: 75
Default another bizarre audio circuit

On Fri, 04 Mar 2011 10:15:02 -0800, John Larkin
wrote:

On Fri, 04 Mar 2011 11:59:58 -0600, John Fields
wrote:

On Fri, 04 Mar 2011 08:18:03 -0800, John Larkin
wrote:

On Fri, 04 Mar 2011 09:18:28 -0600, John Fields
wrote:


On the above, I'm not at odds with you except for the "brutal honesty"
part which, when you're found to be in error, all of a sudden doesn't
apply to you.

---
JF

I make mistakes all the time, and a lot of my ideas get paved over by
somebody else's ideas. I work with some *very* smart people who, in
their areas, know a lot more than I do. That's part of the fun of
playing with ideas.


---
Apples and oranges.

You're talking about who you are at work and I'm talking about who you
are here; obviously two different people.


It's a newsgroup, not life.


---
Since when is interacting with people not life?
---

But if you want to argue over definitions, like whether something
that's unboundedly large can be referred to as "infinite", that's just
words, definitions, and doesn't matter.


---
Total nonsense since if words and definitions didn't matter then
there'd be no purpose for language.

The thing is though, that it can't be unboundedly large as long as
there's something other than zero in the denominator, and if it takes
any power at all to switch it, you're stuck with less than infinite
gain.


What is infinity/1 ? You seem to be arguing that nothing can ever be
unboundedly large since any number can be divided by 1.


---
Huh???

I said something _other_ than zero in the denominator
---

Approaching infinity in the limit, but never quite able to get there.


That's the way infinity tends to work. I was taught that infinity
isn't a number, it's a limit.


---
If that's what you were taught, then you ought to know that the gain
of a latching relay can never be infinite.
---

( Lim (1/x) as x0 ) infinity

which works well enough in engineering.


---
Whatever...

---
JF
  #105   Report Post  
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Phil Hobbs[_2_] Phil Hobbs[_2_] is offline
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Posts: 17
Default another bizarre audio circuit

John Larkin wrote:
On Fri, 4 Mar 2011 07:31:14 -0800 (PST), George Herold
wrote:

On Mar 4, 12:43 am, John Larkin
wrote:
On Thu, 3 Mar 2011 19:08:38 -0800 (PST), George Herold





wrote:
On Mar 3, 6:49 pm, John Larkin
wrote:
On Thu, 3 Mar 2011 15:21:33 -0800 (PST), Bill Sloman

wrote:
On Mar 3, 4:12 pm, John Larkin
wrote:
On Thu, 3 Mar 2011 00:10:16 -0800 (PST), Bill Sloman

wrote:
On Mar 3, 3:32 am, John Larkin
wrote:
On Wed, 2 Mar 2011 17:59:58 -0800 (PST), Bill Sloman

wrote:
On Mar 3, 2:11 am, John Larkin
wrote:
On Wed, 02 Mar 2011 18:36:25 -0600, John Fields

wrote:
On Wed, 02 Mar 2011 08:40:42 -0800, John Larkin
wrote:

I've always sort of liked the classic "GE" tape head/mic preamp
circuit:

ftp://jjlarkin.lmi.net/GEcircuit.jpg

but it occurred to me that it might also make a nice headphone amp...

ftp://jjlarkin.lmi.net/GE_headphone_amp.JPG

Audio tends to be nonsense, but at least the audio guys have fun
playing with circuits, whether they make a lot of sense or not.

John

---
Even though you scorn and ridicule audio, there's nothing wrong with
anyone seeking perfection there, just as there's nothing wrong with
your search for perfection in the genre which pleases _you_ to pursue.
So, speaking of fun, why don't you do a complete design and assign
values to the circuit components and identify the semiconductors?

You're not playing the game. You are sitting in the henhouse, clucking
about the people who do.

He's not playing your game, which involves telling John Larkin how
cute his circuits are.

He's not designing circuits, which is what this newsgroup is about.

You aren't either. Both of you start to cluck and peck when people do
design circuits. No surprise.

Or is that legwork _we're_ supposed to do in order to flesh out your
divine revelation?

Chickenleg work!

It's half the story - a few component values make it a lot easier to
work out what a circuit is doing.

You can't look at a circuit this simple and see what it's doing? OK,
no surprise.

Without the component values, it does take a moment's thought, which
is wasted on a bizarre (if simple) circuit with few potential
applications.

Millions of the "GE" circuit have been used for decades. The mosfet
hybrid is a very reasonable headphone amp.

Post a circuit, doofus. You've forgotten how to do anything but whine.

You are the one who complains all the time. You may have personal
preferences about the nature of the threads that get started here, and
the responses that get posted, but they are only of interest to you.

You are welcome to demonstrate your preferences by choosing to get
involved with particular threads and in your particular reactions to
other responses, but your whining about the nature of those responses
doesn't make the group a more attractive or rewarding environment.

In the meantime, I'll post a circuit when I've got a circuit worth
posting. Posting a example - without comnponent values - of a circuit
that has been used in millions, for decades, doesn't strike me as a
profitable use of bandwidth, but that is a personal preference.

What I did was spin a signal-level bipolar circuit into a
bipolar-mosfet power amp of similar topology.

The resulting dynamics is very interesting. Well, not to you.

John- Hide quoted text -

- Show quoted text -

Yeah, I didn't get the inductor part. Do I have to spice it? Or does
it have to do with head phone dynamics.

Say, and what about using the postive rail of an opamp as an output?
I never heard of that.

George H.

Old trick. Here's a bipolar-swing version.

ftp://jjlarkin.lmi.net/Opamp_boost_2.JPG

A similar thing is sometimes done to boost the current of an LM317, by
using its input current to drive the base of a PNP "helper"
transistor.

I use a variant of this circuit as a current splitter in my NMR
gradient amps.

I can't spell, or type, either.

John- Hide quoted text -

- Show quoted text -


Intersesting thanks. Is there a reason not to take the feedback from
the output (transistor collectors) rather than the opamp itself?

George H.


Depends on what you want to do. In my gradient amps, I want the
overall box to be a current source, so I don't use any voltage
feedback. The upper and lower boost transistors are replaced by
precision current mirrors, and I usually cascode the opamp supply
currents up into the mirrors, bacause the rail voltages tend to be
high.

As a boosted voltage amp, you'd generally want voltage feedback from
the final output. The feedback can go into the inputs of the opamp,
but I've seen cases where the feedback was applied to the *output* of
the opamp.

John


Having some feedback to the output is a win, because the feedback goes
both ways--the op amp can provide some of the output. It's also a bit
quicker for large signal stuff, because the error current goes straight
out the supply leads without going through the frequency compensation
stuff in the front end. Of course that complicates the overall
frequency compensation of the amp.

Making composite amps with decent settling behaviour can be pretty tough.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058

email: hobbs (atsign) electrooptical (period) net
http://electrooptical.net


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Phil Hobbs[_2_] Phil Hobbs[_2_] is offline
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Posts: 17
Default another bizarre audio circuit

John Fields wrote:
On Fri, 04 Mar 2011 08:18:03 -0800, John Larkin
wrote:

On Fri, 04 Mar 2011 09:18:28 -0600, John Fields
wrote:


On the above, I'm not at odds with you except for the "brutal honesty"
part which, when you're found to be in error, all of a sudden doesn't
apply to you.

---
JF


I make mistakes all the time, and a lot of my ideas get paved over by
somebody else's ideas. I work with some *very* smart people who, in
their areas, know a lot more than I do. That's part of the fun of
playing with ideas.


---
Apples and oranges.

You're talking about who you are at work and I'm talking about who you
are here; obviously two different people.
---

But if you want to argue over definitions, like whether something
that's unboundedly large can be referred to as "infinite", that's just
words, definitions, and doesn't matter.


---
Total nonsense since if words and definitions didn't matter then
there'd be no purpose for language.

The thing is though, that it can't be unboundedly large as long as
there's something other than zero in the denominator, and if it takes
any power at all to switch it, you're stuck with less than infinite
gain.

Approaching infinity in the limit, but never quite able to get there.
---

It certainly doesn't affect
the electronics. A latching relay does what it does.

John


---
A rose, by any other name...

---
JF


Can we please declare a weekend moratorium on ****ing contests? Pretty
please?

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058

email: hobbs (atsign) electrooptical (period) net
http://electrooptical.net
  #107   Report Post  
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John Fields John Fields is offline
external usenet poster
 
Posts: 75
Default another bizarre audio circuit

On Fri, 04 Mar 2011 15:03:20 -0500, Phil Hobbs
wrote:


Can we please declare a weekend moratorium on ****ing contests? Pretty
please?

Cheers

Phil Hobbs


---
Works for me! :-)

---
JF
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Fred Bloggs[_2_] Fred Bloggs[_2_] is offline
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Posts: 6
Default another bizarre audio circuit

On Mar 4, 12:54*pm, John Larkin
wrote:
On Thu, 3 Mar 2011 19:53:58 -0800 (PST), Fred Bloggs





wrote:
On Mar 2, 5:58 pm, John Larkin
wrote:
On Wed, 2 Mar 2011 14:55:18 -0800 (PST), Fred Bloggs


wrote:
On Mar 2, 4:33 pm, John Larkin
wrote:
On Wed, 2 Mar 2011 12:03:38 -0800 (PST), Fred Bloggs


wrote:
On Mar 2, 11:40 am, John Larkin
wrote:
I've always sort of liked the classic "GE" tape head/mic preamp
circuit:


ftp://jjlarkin.lmi.net/GEcircuit.jpg


but it occurred to me that it might also make a nice headphone amp...


ftp://jjlarkin.lmi.net/GE_headphone_amp.JPG


Audio tends to be nonsense, but at least the audio guys have fun
playing with circuits, whether they make a lot of sense or not.


John


Bizarre??? Just a standard buffered input CE with negative feedback DC
bias to stabilize the operating point against Vbe and reverse leakage
collector current change with temperature- a textbook circuit...


Which textbook?


John- Hide quoted text -


- Show quoted text -


Just about any textbook that goes into bias point sensitivity analysis
of transistor circuits- you remember the S- functions, mainly ICQ
stability. The big three were HFE, VBE, and ICBO. Then the rest of
your circuit is just ac-bypass and the shunt-series feedback for
signals. I've seen it dozens of times.


I bet you haven't seen the bipolar+mosfet version, with inductive
pullup, used as a power amp.


John- Hide quoted text -


- Show quoted text -


I don't see the MOSFET being all that much of a change. And as for the
inductor pull-up, this just doesn't make sense for low wattage high
impedance headphone loads. Your inductive reactance needs to be a good
few integer multiples of the load impedance, making these things
prohibitively large if not unobtainable for a headphone app- you would
use far less iron/ ferrite by boost switching your supply to
accommodate the output swing...guess that's why I've never seen the
inductive pullup here.


Of course you haven't seen this circuit befo I just invented it.

But inductors were widely used as plate loads in the tube days. Tubes
were expensive and had low gains, so transformers and inductors were
sensible. Early transistor amps used lots of transformers, for the
same reasons.

John- Hide quoted text -

- Show quoted text -


I thinking you are confusing your app with peaking coils which were
one of several techniques used to broadband the amplifier- that's a
totally different application and it was practical because the
reactance was only important in the 10's KHz band or higher- this is
not the case for a 20-20K Hz headphone circuit.
  #109   Report Post  
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[email protected] krw@att.bizzzzzzzzzzzz is offline
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Posts: 20
Default another bizarre audio circuit

On Thu, 03 Mar 2011 21:14:26 -0800, John Larkin
wrote:

On Thu, 03 Mar 2011 18:04:33 -0800, Chieftain of the Carpet Crawlers
wrote:

On Thu, 03 Mar 2011 08:59:38 -0800, John Larkin
wrote:

Stop whining and clucking about personalities


Stop with the retarded colloquialisms (or attempts at them). You
stupid ****. That is about as plain as it gets.

You show with nearly every post just how little a man you are. If you
even get that qualification.
Your personality is that of a circus flea.

Dance, mother****er.


The thing you guys have in common is that you suck at electronics, and
you know it. That pretty much explains everything.


....except why they are here.
  #110   Report Post  
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John Larkin John Larkin is offline
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Posts: 151
Default another bizarre audio circuit

On Fri, 04 Mar 2011 17:57:05 -0600, "
wrote:

On Thu, 03 Mar 2011 21:14:26 -0800, John Larkin
wrote:

On Thu, 03 Mar 2011 18:04:33 -0800, Chieftain of the Carpet Crawlers
wrote:

On Thu, 03 Mar 2011 08:59:38 -0800, John Larkin
wrote:

Stop whining and clucking about personalities

Stop with the retarded colloquialisms (or attempts at them). You
stupid ****. That is about as plain as it gets.

You show with nearly every post just how little a man you are. If you
even get that qualification.
Your personality is that of a circus flea.

Dance, mother****er.


The thing you guys have in common is that you suck at electronics, and
you know it. That pretty much explains everything.


...except why they are here.


Oh. Maybe they suck at electronics and *don't* know it.

John



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[email protected] krw@att.bizzzzzzzzzzzz is offline
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Posts: 20
Default another bizarre audio circuit

On Fri, 04 Mar 2011 16:22:58 -0800, John Larkin
wrote:

On Fri, 04 Mar 2011 17:57:05 -0600, "
wrote:

On Thu, 03 Mar 2011 21:14:26 -0800, John Larkin
wrote:

On Thu, 03 Mar 2011 18:04:33 -0800, Chieftain of the Carpet Crawlers
g wrote:

On Thu, 03 Mar 2011 08:59:38 -0800, John Larkin
wrote:

Stop whining and clucking about personalities

Stop with the retarded colloquialisms (or attempts at them). You
stupid ****. That is about as plain as it gets.

You show with nearly every post just how little a man you are. If you
even get that qualification.
Your personality is that of a circus flea.

Dance, mother****er.

The thing you guys have in common is that you suck at electronics, and
you know it. That pretty much explains everything.


...except why they are here.


Oh. Maybe they suck at electronics and *don't* know it.


Ya, think maybe?
  #112   Report Post  
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George Herold George Herold is offline
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Posts: 5
Default another bizarre audio circuit

On Mar 4, 3:01*pm, Phil Hobbs
wrote:
John Larkin wrote:
On Fri, 4 Mar 2011 07:31:14 -0800 (PST), George Herold
*wrote:


On Mar 4, 12:43 am, John Larkin
*wrote:
On Thu, 3 Mar 2011 19:08:38 -0800 (PST), George Herold


*wrote:
On Mar 3, 6:49 pm, John Larkin
*wrote:
On Thu, 3 Mar 2011 15:21:33 -0800 (PST), Bill Sloman


*wrote:
On Mar 3, 4:12 pm, John Larkin
*wrote:
On Thu, 3 Mar 2011 00:10:16 -0800 (PST), Bill Sloman


*wrote:
On Mar 3, 3:32 am, John Larkin
*wrote:
On Wed, 2 Mar 2011 17:59:58 -0800 (PST), Bill Sloman


*wrote:
On Mar 3, 2:11 am, John Larkin
*wrote:
On Wed, 02 Mar 2011 18:36:25 -0600, John Fields


*wrote:
On Wed, 02 Mar 2011 08:40:42 -0800, John Larkin
*wrote:


I've always sort of liked the classic "GE" tape head/mic preamp
circuit:


ftp://jjlarkin.lmi.net/GEcircuit.jpg


but it occurred to me that it might also make a nice headphone amp...


ftp://jjlarkin.lmi.net/GE_headphone_amp.JPG


Audio tends to be nonsense, but at least the audio guys have fun
playing with circuits, whether they make a lot of sense or not.


John


---
Even though you scorn and ridicule audio, there's nothing wrong with
anyone seeking perfection there, just as there's nothing wrong with
your search for perfection in the genre which pleases _you_ to pursue.
So, speaking of fun, why don't you do a complete design and assign
values to the circuit components and identify the semiconductors?


You're not playing the game. You are sitting in the henhouse, clucking
about the people who do.


He's not playing your game, which involves telling John Larkin how
cute his circuits are.


He's not designing circuits, which is what this newsgroup is about.


You aren't either. Both of you start to cluck and peck when people do
design circuits. No surprise.


Or is that legwork _we're_ supposed to do in order to flesh out your
divine revelation?


Chickenleg work!


It's half the story - a few component values make it a lot easier to
work out what a circuit is doing.


You can't look at a circuit this simple and see what it's doing? OK,
no surprise.


Without the component values, it does take a moment's thought, which
is wasted on a bizarre (if simple) circuit with few potential
applications.


Millions of the "GE" circuit have been used for decades. The mosfet
hybrid is a very reasonable headphone amp.


Post a circuit, doofus. You've forgotten how to do anything but whine.


You are the one who complains all the time. You may have personal
preferences about the nature of the threads that get started here, and
the responses that get posted, but they are only of interest to you.


You are welcome to demonstrate your preferences by choosing to get
involved with particular threads and in your particular reactions to
other responses, but your whining about the nature of those responses
doesn't make the group a more attractive or rewarding environment.


In the meantime, I'll post a circuit when I've got a circuit worth
posting. Posting a example - without comnponent values - of a circuit
that has been used in millions, for decades, doesn't strike me as a
profitable use of bandwidth, but that is a personal preference.


What I did was spin a signal-level bipolar circuit into a
bipolar-mosfet power amp of similar topology.


The resulting dynamics is very interesting. Well, not to you.


John- Hide quoted text -


- Show quoted text -


Yeah, I didn't get the inductor part. *Do I have to spice it? *Or does
it have to do with head phone dynamics.


Say, and what about using the postive rail of an opamp as an output?
I never heard of that.


George H.


Old trick. Here's a bipolar-swing version.


ftp://jjlarkin.lmi.net/Opamp_boost_2.JPG


A similar thing is sometimes done to boost the current of an LM317, by
using its input current to drive the base of a PNP "helper"
transistor.


I use a variant of this circuit as a current splitter in my NMR
gradient amps.


I can't spell, or type, either.


John- Hide quoted text -


- Show quoted text -


Intersesting thanks. *Is there a reason not to take the feedback from
the output (transistor collectors) rather than the opamp itself?


George H.


Depends on what you want to do. In my gradient amps, I want the
overall box to be a current source, so I don't use any voltage
feedback. The upper and lower boost transistors are replaced by
precision current mirrors, and I usually cascode the opamp supply
currents up into the mirrors, bacause the rail voltages tend to be
high.


As a boosted voltage amp, you'd generally want voltage feedback from
the final output. The feedback can go into the inputs of the opamp,
but I've seen cases where the feedback was applied to the *output* of
the opamp.


John


Having some feedback to the output is a win, because the feedback goes
both ways--the op amp can provide some of the output. *It's also a bit
quicker for large signal stuff, because the error current goes straight
out the supply leads without going through the frequency compensation
stuff in the front end. *Of course that complicates the overall
frequency compensation of the amp.


Yeah it seems like you can get gob's of current out of it. You're not
stuck with what the opamp can supply. There might be issues near
zero. So I think you're suggesting included John's R6 and taking the
feedback from after that. (At least that's how I drew it.)

Making composite amps with decent settling behaviour can be pretty tough.


Well if it was easy I would have already heard about it.

George H.


Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058

email: hobbs (atsign) electrooptical (period) nethttp://electrooptical.net- Hide quoted text -

- Show quoted text -


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TheQuickBrownFox TheQuickBrownFox is offline
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Posts: 7
Default another bizarre audio circuit

On Fri, 04 Mar 2011 10:15:02 -0800, John Larkin
wrote:

It's a newsgroup, not life.


You're a newsgroup abuser, not a man.
  #114   Report Post  
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John Larkin John Larkin is offline
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Posts: 151
Default another bizarre audio circuit

On Fri, 04 Mar 2011 18:11:07 -0800, TheQuickBrownFox
wrote:

On Fri, 04 Mar 2011 10:15:02 -0800, John Larkin
wrote:

It's a newsgroup, not life.


You're a newsgroup abuser, not a man.


Write to your congresswoman.

John

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Chieftain of the Carpet Crawlers Chieftain of the Carpet Crawlers is offline
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Posts: 10
Default another bizarre audio circuit

On Fri, 4 Mar 2011 10:56:32 -0800 (PST), Bill Sloman
wrote:

On Mar 4, 12:59*pm, Chieftain of the Carpet Crawlers
wrote:
On Fri, 4 Mar 2011 02:35:52 -0800 (PST), Bill Sloman

wrote:

Not really. Most of the people who post here haven't used a 555 for
years.


* You do not know that,


A similar thread to this a few years ago prompted a bunch of responses
saying exactly that, from people with a history in this group.


Bull****. That is what YOU would have liked them to have said.

Essentially, you have proven nothing except that fact that you do NOT
know what ANY others think.

and you saying it does not make it true.


Obviously not. It does happen to be true, none-the-less.


Obviously not, idiot. You are 100% convoluted, none-the-less.

* You are an idiot to think so.


You may think so.


Actually, me pegging you as an idiot is far more accurate than you
pegging all the members of the group (and then some) as thinking one way
or the other about a given topic. You are about as clueless as any man
can get.



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TheQuickBrownFox TheQuickBrownFox is offline
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Posts: 7
Default another bizarre audio circuit

On Fri, 04 Mar 2011 15:03:20 -0500, Phil Hobbs
wrote:

John Fields wrote:
On Fri, 04 Mar 2011 08:18:03 -0800, John Larkin
wrote:

On Fri, 04 Mar 2011 09:18:28 -0600, John Fields
wrote:


On the above, I'm not at odds with you except for the "brutal honesty"
part which, when you're found to be in error, all of a sudden doesn't
apply to you.

---
JF

I make mistakes all the time, and a lot of my ideas get paved over by
somebody else's ideas. I work with some *very* smart people who, in
their areas, know a lot more than I do. That's part of the fun of
playing with ideas.


---
Apples and oranges.

You're talking about who you are at work and I'm talking about who you
are here; obviously two different people.
---

But if you want to argue over definitions, like whether something
that's unboundedly large can be referred to as "infinite", that's just
words, definitions, and doesn't matter.


---
Total nonsense since if words and definitions didn't matter then
there'd be no purpose for language.

The thing is though, that it can't be unboundedly large as long as
there's something other than zero in the denominator, and if it takes
any power at all to switch it, you're stuck with less than infinite
gain.

Approaching infinity in the limit, but never quite able to get there.
---

It certainly doesn't affect
the electronics. A latching relay does what it does.

John


---
A rose, by any other name...

---
JF


Can we please declare a weekend moratorium on ****ing contests? Pretty
please?

Cheers

Phil Hobbs



I can guarantee you that Larkin is the only asshole in the group that
cannot comply.

For one thing, that is NOT what JF is doing.

Larking would like to think that he could win a ****ing contest, but he
falls short of the requisite needs of being a man, and having a dick.

The closest he comes to having a dick is the fact that he is typically a
dickhead.
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Bill Sloman Bill Sloman is offline
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Default another bizarre audio circuit

On Mar 5, 3:22*am, Chieftain of the Carpet Crawlers
wrote:
On Fri, 4 Mar 2011 10:56:32 -0800 (PST), Bill Sloman

wrote:
On Mar 4, 12:59 pm, Chieftain of the Carpet Crawlers
wrote:
On Fri, 4 Mar 2011 02:35:52 -0800 (PST), Bill Sloman


wrote:


Not really. Most of the people who post here haven't used a 555 for
years.


You do not know that,


A similar thread to this a few years ago prompted a bunch of responses
saying exactly that, from people with a history in this group.


* Bull****. That is what YOU would have liked them to have said.


Dream on. If you had any credibility I'd find the thread, but since
it's you, why should I bother?

* Essentially, you have proven nothing except that fact that you do NOT
know what ANY others think.


I haven't bothered to prove anything. I've just made an assertion. It
happens to be a correct assertion, but you are too dim to realise
this, and too low in the pecking order for your opinion to matter.

and you saying it does not make it true.


Obviously not. It does happen to be true, none-the-less.


* Obviously not, idiot. *You are 100% convoluted, none-the-less.

You are an idiot to think so.


You may think so.


* Actually, me pegging you as an idiot is far more accurate than you
pegging all the members of the group (and then some) as thinking one way
or the other about a given topic. *You are about as clueless as any man
can get.


Do go on. This group in short on good jokes, and you make a pretty
good substitute.

--
Bill Sloman, Nijmegen

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Chieftain of the Carpet Crawlers Chieftain of the Carpet Crawlers is offline
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Posts: 10
Default another bizarre audio circuit

On Fri, 4 Mar 2011 19:35:32 -0800 (PST), Bill Sloman
wrote:

and too low in the pecking order



Sorry cast boy, but if we are declaring levels of attainment and
awareness here, you would certainly be the loser against me.

You don't even know what a 555 timer IC is for, much less the fact that
it is still used. Far more than you are willing to believe, since it
proves you wrong.

And you are... both wrong AND the loser. Bye.
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John Larkin John Larkin is offline
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Default another bizarre audio circuit

On Fri, 4 Mar 2011 14:23:17 -0800 (PST), Fred Bloggs
wrote:

On Mar 4, 12:54*pm, John Larkin
wrote:
On Thu, 3 Mar 2011 19:53:58 -0800 (PST), Fred Bloggs





wrote:
On Mar 2, 5:58 pm, John Larkin
wrote:
On Wed, 2 Mar 2011 14:55:18 -0800 (PST), Fred Bloggs


wrote:
On Mar 2, 4:33 pm, John Larkin
wrote:
On Wed, 2 Mar 2011 12:03:38 -0800 (PST), Fred Bloggs


wrote:
On Mar 2, 11:40 am, John Larkin
wrote:
I've always sort of liked the classic "GE" tape head/mic preamp
circuit:


ftp://jjlarkin.lmi.net/GEcircuit.jpg


but it occurred to me that it might also make a nice headphone amp...


ftp://jjlarkin.lmi.net/GE_headphone_amp.JPG


Audio tends to be nonsense, but at least the audio guys have fun
playing with circuits, whether they make a lot of sense or not.


John


Bizarre??? Just a standard buffered input CE with negative feedback DC
bias to stabilize the operating point against Vbe and reverse leakage
collector current change with temperature- a textbook circuit...


Which textbook?


John- Hide quoted text -


- Show quoted text -


Just about any textbook that goes into bias point sensitivity analysis
of transistor circuits- you remember the S- functions, mainly ICQ
stability. The big three were HFE, VBE, and ICBO. Then the rest of
your circuit is just ac-bypass and the shunt-series feedback for
signals. I've seen it dozens of times.


I bet you haven't seen the bipolar+mosfet version, with inductive
pullup, used as a power amp.


John- Hide quoted text -


- Show quoted text -


I don't see the MOSFET being all that much of a change. And as for the
inductor pull-up, this just doesn't make sense for low wattage high
impedance headphone loads. Your inductive reactance needs to be a good
few integer multiples of the load impedance, making these things
prohibitively large if not unobtainable for a headphone app- you would
use far less iron/ ferrite by boost switching your supply to
accommodate the output swing...guess that's why I've never seen the
inductive pullup here.


Of course you haven't seen this circuit befo I just invented it.

But inductors were widely used as plate loads in the tube days. Tubes
were expensive and had low gains, so transformers and inductors were
sensible. Early transistor amps used lots of transformers, for the
same reasons.

John- Hide quoted text -

- Show quoted text -


I thinking you are confusing your app with peaking coils which were
one of several techniques used to broadband the amplifier- that's a
totally different application and it was practical because the
reactance was only important in the 10's KHz band or higher- this is
not the case for a 20-20K Hz headphone circuit.


Am not!

ftp://jjlarkin.lmi.net/Chokes.JPG

John

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John Larkin John Larkin is offline
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Default another bizarre audio circuit

On Fri, 04 Mar 2011 18:27:35 -0800, TheQuickBrownFox
wrote:

On Fri, 04 Mar 2011 15:03:20 -0500, Phil Hobbs
wrote:

John Fields wrote:
On Fri, 04 Mar 2011 08:18:03 -0800, John Larkin
wrote:

On Fri, 04 Mar 2011 09:18:28 -0600, John Fields
wrote:

On the above, I'm not at odds with you except for the "brutal honesty"
part which, when you're found to be in error, all of a sudden doesn't
apply to you.

---
JF

I make mistakes all the time, and a lot of my ideas get paved over by
somebody else's ideas. I work with some *very* smart people who, in
their areas, know a lot more than I do. That's part of the fun of
playing with ideas.

---
Apples and oranges.

You're talking about who you are at work and I'm talking about who you
are here; obviously two different people.
---

But if you want to argue over definitions, like whether something
that's unboundedly large can be referred to as "infinite", that's just
words, definitions, and doesn't matter.

---
Total nonsense since if words and definitions didn't matter then
there'd be no purpose for language.

The thing is though, that it can't be unboundedly large as long as
there's something other than zero in the denominator, and if it takes
any power at all to switch it, you're stuck with less than infinite
gain.

Approaching infinity in the limit, but never quite able to get there.
---

It certainly doesn't affect
the electronics. A latching relay does what it does.

John

---
A rose, by any other name...

---
JF


Can we please declare a weekend moratorium on ****ing contests? Pretty
please?

Cheers

Phil Hobbs



I can guarantee you that Larkin is the only asshole in the group that
cannot comply.


Hilarious. And very unclear on the concept.

John

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