On Tue, 13 Mar 2007 23:34:00 +0000, Eeyore
wrote:



Jim Thompson wrote:

There is minimal engineering here, and when I attempt to be a teacher
of my craft I get nothing but BS.

I'm waiting to hear a meaningful critique and see an improved design.

---
LOL, like you're some kind of judge or something???


--
JF

On Wed, 14 Mar 2007 00:23:40 -0300, YD wrote:

Late at night, by candle light, Jim Thompson
penned this immortal
opus:

[snip]

There is minimal engineering here, and when I attempt to be a teacher
of my craft I get nothing but BS.


Maybe that's due to your being such a master of BS.

- YD.

Nope, I'm a Master of EE ;-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

"Eeyore" wrote in message
...

Genome wrote:

However, I did work out an equation for the gain of your compound
differential pair that seems fairly close to the mark.....

Bpnp = 05 Av = 56.9dB
Bpnp = 10 Av = 60.6dB +3.7dB
Bpnp = 20 Av = 64.4dB +3.8dB
Bpnp = 40 Av = 67.8dB +3.4dB
Bpnp = 80 Av = 70.5dB +2.7dB

That looks, more or less, like the gain depends on Beta in the manner
suggested.

You reckon the beta is 5 ? Try an average figure of around 200.

Those numbers look way out anyway.

Graham


I suppose that's why I stepped it from 5 to 80.

Of course you'll ignore anything in an effort to try and prove how good you
think others should think you are.

Next time you edit a post to suit yourself try and get it right. You should
have removed the figures for Bnpn 5.

The numbers come from an LTspice simulation but I suppose quoting them gives
you a chance to criticise once more in your never ending effort to prove how
good we should think you are.

Perhaps you should change your nym.....

Yip, yip, yip, yip, yip ,yip, yip ,yip, yip ,yip, yip ,yip, yip, yip, yip,
Yap, yap, yap, yap, yap, yap, yap, yap, yap, yap, yap, yap, yap,
Grrrrrrrrrrrrr, ruff, ruff rufff. grrr, grrrr, grrr,
Yip, yip, yip, yap, yip ,yap, yap ,yap, yip ,yip, yip ,yap, yip, yap, yip,

Doesn't sound too much like a donkey.

DNA

John Fields wrote:

Eeyore wrote:
John Fields wrote:
Eeyore wrote:
Genome wrote:

On the basis of the above analysis..... the gain is going to vary all over
the shop as Bnpn (and other stuff) varies. So yes it is crap.

WRONG !

Every serious pro-audio mixer has a mic pre-amp circuit that's not a heck of a
lot different to this since the late 1970s.

It performs really rather well. Has no-one yet considered simulating it ?

---
Why not get off of your lazy ass, ass, and do it yourself?

I've done better than that. I've sold it to the public.

---
P.T. Barnum was right, then, but that's not the point.

The point is, if you're asking for a simulation why don't you do it
yourself instead of expecting someone else to do your leg work for
you?

I *have* simulated it in the past. I don't have the file here though.

Graham

John Fields wrote:

Eeyore wrote:
Jim Thompson wrote:

There is minimal engineering here, and when I attempt to be a teacher
of my craft I get nothing but BS.

I'm waiting to hear a meaningful critique and see an improved design.

---
LOL, like you're some kind of judge or something???

I seem to know more about this area than anyone else here.

Graham

Genome wrote:

"Eeyore" wrote in message
Genome wrote:

However, I did work out an equation for the gain of your compound
differential pair that seems fairly close to the mark.....

Bpnp = 05 Av = 56.9dB
Bpnp = 10 Av = 60.6dB +3.7dB
Bpnp = 20 Av = 64.4dB +3.8dB
Bpnp = 40 Av = 67.8dB +3.4dB
Bpnp = 80 Av = 70.5dB +2.7dB

That looks, more or less, like the gain depends on Beta in the manner
suggested.

You reckon the beta is 5 ? Try an average figure of around 200.

Those numbers look way out anyway.


I suppose that's why I stepped it from 5 to 80.

Of course you'll ignore anything in an effort to try and prove how good you
think others should think you are.

Next time you edit a post to suit yourself try and get it right. You should
have removed the figures for Bnpn 5.

What are you rambling on about now ?


The numbers come from an LTspice simulation but I suppose quoting them gives
you a chance to criticise once more in your never ending effort to prove how
good we should think you are.

Perhaps you should change your nym.....

Perhaps you should look at this data sheet for a BC549 ? Minimum beta @ 2mA is
*420* !

Graham

On Tue, 13 Mar 2007 16:29:09 +0000, ehsjr wrote:

Jim Thompson wrote:

snip




Some of us have not given you BS, and do appreciate
the teaching.

Ed


Agreed, unfortunately I never got the point Jim was
trying to make with Colin. Maybe I missed it in all the
blowing.

On Wed, 14 Mar 2007 08:14:59 -0700, Jitt wrote:

On Tue, 13 Mar 2007 16:29:09 +0000, ehsjr wrote:

Jim Thompson wrote:

snip




Some of us have not given you BS, and do appreciate
the teaching.

Ed


Agreed, unfortunately I never got the point Jim was
trying to make with Colin. Maybe I missed it in all the
blowing.

I was just trying to get Colin to write down the complete gain
equation... not a piece here and a piece there.

I wanted him (and all of you) to be aware of where gain was thrown
away.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

"Jim Thompson" wrote in
message ...
On Wed, 14 Mar 2007 08:14:59 -0700, Jitt wrote:

On Tue, 13 Mar 2007 16:29:09 +0000, ehsjr wrote:

Jim Thompson wrote:

snip




Some of us have not given you BS, and do appreciate
the teaching.

Ed


Agreed, unfortunately I never got the point Jim was
trying to make with Colin. Maybe I missed it in all the
blowing.

I was just trying to get Colin to write down the complete gain
equation... not a piece here and a piece there.

I wanted him (and all of you) to be aware of where gain was thrown
away.

but just having an equation wich says g=f(vr1) doesnt tell you that,
especially as the point you were trying to make was invalid anyway cos of
the confusion over the gain.

Colin =^.^=

On Wed, 14 Mar 2007 17:49:21 GMT, "colin"
wrote:

"Jim Thompson" wrote in
message ...
On Wed, 14 Mar 2007 08:14:59 -0700, Jitt wrote:

On Tue, 13 Mar 2007 16:29:09 +0000, ehsjr wrote:

Jim Thompson wrote:

snip




Some of us have not given you BS, and do appreciate
the teaching.

Ed


Agreed, unfortunately I never got the point Jim was
trying to make with Colin. Maybe I missed it in all the
blowing.

I was just trying to get Colin to write down the complete gain
equation... not a piece here and a piece there.

I wanted him (and all of you) to be aware of where gain was thrown
away.

but just having an equation wich says g=f(vr1) doesnt tell you that,
especially as the point you were trying to make was invalid anyway cos of
the confusion over the gain.

Colin =^.^=


In the capacitively-coupled configuration there's still 20dB tossed
that I consider unsavory.

In Graham's latest version that is DC coupled (virtual ground gimmick)
this doesn't happen.

Except for running at a risky common-mode voltage, that version is
AOK! And that problem is trivial to fix.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

"Jim Thompson" wrote in
message ...
On Wed, 14 Mar 2007 17:49:21 GMT, "colin"
wrote:

"Jim Thompson" wrote in
message ...
On Wed, 14 Mar 2007 08:14:59 -0700, Jitt wrote:

On Tue, 13 Mar 2007 16:29:09 +0000, ehsjr wrote:

Jim Thompson wrote:

snip




Some of us have not given you BS, and do appreciate
the teaching.

Ed


Agreed, unfortunately I never got the point Jim was
trying to make with Colin. Maybe I missed it in all the
blowing.

I was just trying to get Colin to write down the complete gain
equation... not a piece here and a piece there.

I wanted him (and all of you) to be aware of where gain was thrown
away.

but just having an equation wich says g=f(vr1) doesnt tell you that,
especially as the point you were trying to make was invalid anyway cos of
the confusion over the gain.

Colin =^.^=


In the capacitively-coupled configuration there's still 20dB tossed
that I consider unsavory.

In Graham's latest version that is DC coupled (virtual ground gimmick)
this doesn't happen.

Except for running at a risky common-mode voltage, that version is
AOK! And that problem is trivial to fix.

20db where is it being lost?
the op amp will generate a certain amount of noise at the output as its gain
is fixed,
as long as there is sufficient output signal this wil not be dominant on the
SNR.

as for your point on noise gain I havnt looked at that yet.
first im gona have a rumage thru my many boxes to see if I can find some
bright white leds wich i vageuly remember ordering many years ago but didnt
get round to using.

Colin =^.^=

Jim Thompson wrote:
On Wed, 14 Mar 2007 08:14:59 -0700, Jitt wrote:


On Tue, 13 Mar 2007 16:29:09 +0000, ehsjr wrote:


Jim Thompson wrote:

snip

Some of us have not given you BS, and do appreciate
the teaching.

Ed


Agreed, unfortunately I never got the point Jim was
trying to make with Colin. Maybe I missed it in all the
blowing.


I was just trying to get Colin to write down the complete gain
equation... not a piece here and a piece there.

I wanted him (and all of you) to be aware of where gain was thrown
away.

...Jim Thompson

Well, you copped out with that "improved" circuit you posted to abse.
There was an interesting problem the australopiths couldn't get around,
and you went with it too...

On Thu, 15 Mar 2007 10:30:11 GMT, Fred Bloggs
wrote:



Jim Thompson wrote:
On Wed, 14 Mar 2007 08:14:59 -0700, Jitt wrote:


On Tue, 13 Mar 2007 16:29:09 +0000, ehsjr wrote:


Jim Thompson wrote:

snip

Some of us have not given you BS, and do appreciate
the teaching.

Ed


Agreed, unfortunately I never got the point Jim was
trying to make with Colin. Maybe I missed it in all the
blowing.


I was just trying to get Colin to write down the complete gain
equation... not a piece here and a piece there.

I wanted him (and all of you) to be aware of where gain was thrown
away.

...Jim Thompson

Well, you copped out with that "improved" circuit you posted to abse.
There was an interesting problem the australopiths couldn't get around,
and you went with it too...

Don't be coy, Fred. Tell us what it is.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

Jim Thompson wrote:

Fred Bloggs wrote:
Jim Thompson wrote:

I was just trying to get Colin to write down the complete gain
equation... not a piece here and a piece there.

I wanted him (and all of you) to be aware of where gain was thrown
away.

...Jim Thompson

Well, you copped out with that "improved" circuit you posted to abse.
There was an interesting problem the australopiths couldn't get around,
and you went with it too...

Don't be coy, Fred. Tell us what it is.

I think he means you kept the 2k2 'collector loads'. R4 and R8 in your case.

Graham