Audio Amp Crossover Distortion?

line?

25 years? Circuit simulators existed more than 40 years ago.
Reply to
krw
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You're assuming Jim's career launched 50 years ago, when upon walking into a firm off the street without a clue, he got a job designing integrated circuits. Then, 25 years later, simulators appeared.

Indeed, it is quite obvious that a little math around here wouldn't be such a bad thing.

Reply to
Kaz Kylheku

Amen! ...Jim Thompson

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| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
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Reply to
Jim Thompson

Because you loss the dynamic range of voltage you need to work with. High gain units of around 1000 or more are typically darlington and even suffer from a worse faith in your case. More 2 or more diode drops of voltage. Consider the schematic below for an idea. THis uses 2 NPN for outputs. This suffers from 2 diode drops only. One from the upper NPN and one from the Op-amp if you don't have a rail type. Of course, if you want to use a couple of inverting units at the top you can bring it down to 1 diode drop.

8 Volt Rail +-------------------------+ | | + |/ Op-Amp out put +--------+-------------+| NPN + |>

| + V 1n914 | GND 10k | | + '-' | + | | + | | G+D G+D (created by AACircuit v1.28.6 beta 04/19/05

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Jamie

Reply to
Jamie

Well, he's just about to turn 19 (76 in human years).

You might try it. Unless he started his career before age 11 (76-40-25), I doubt his statement. Note that this assumes I used the very first circuit simulators, which I highly doubt.

Reply to
krw

line?

I suppose I could, but I don't know where that would lead me to?

In any case, the LT part# I used in the sim was a low quiescent type to start with. I am sure as simple as that circuit is, the sim can't be that far off. I suppose if you select an opamp that has more than one diode drop from the rails it could cause the outputs to have a high Qu level. But why would you want to use a op-amp that bad? Infact I can't think of one that has more than 1 diode drop on the rails at the moment.

And Like I said, proven circuits that are still operating today tells me alot..

Back in the old days my HP calculator, slide rule and lots of paper was my friend. With Polaroid's of scope shots stuffed in scrap books.

Btw

It just came to me, this type of circuit is used to drive a optics focus coil current mode amplifier on a 2 Mev irradiation unit. The lower NPN is used to suppress the reactive energy when throttling back instead of using a snubber or diode, this keeps it symmetrical when we turn off the mag field to avoid unexpected beam steering. That uses a large power IC audio amplifier with the base of the transistors in the rails of the IC with some by pass R to set the Qu I.

Jamie

Reply to
Jamie

The only thing I ever did was tried out Verilog and I absolutely hated it..

It may have been greatly improved since then but it just didn't turn me on.

Being that I also do C, Pascal, Asm etc, you would think that would just fit in but it didn't.

Jamie

Reply to
Jamie

circuits.

Huh? In English, please.

I don't like C, so have never bothered with Verilog. VHDL (and likewise, PL/I) are much more my style.

I still don't understand the relevance.

Reply to
krw

circuits.

Ok, if you say so.

Jamie

Reply to
Jamie

circuits.

Please! I'm turning 18 ;-)

...Jim Thompson

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| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
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Reply to
Jim Thompson

[snip]

Might lead to understanding rather than groping.

Naaaah! It tell me the great disaster is about to befall you.

Stay awake tonight... your end is near ;-) ...Jim Thompson

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| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
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Reply to
Jim Thompson

circuits.

a

Yeah, you got me. What does Verilog have to do with circuit simulators? ...or C, or Pascal, or Asm, or...

Reply to
krw

Connecting the op amp output to the circuit's output via a suitably-chosen small resistance gives you a nice combination of feedforward at small signals and output-stage feedback at large signals. Frequency compensation can be a bit squirrelly.

Cheers

Phil Hobbs

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Dr Philip C D Hobbs
Principal Consultant
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Phil Hobbs

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