Audio Power Amplifier Design book- Douglas Self wants your opinions

[Esperado]

I've learned my lessons on this forum..

Did we were in the same nursery school ?

 

[Dave Zan]

Nah, the Cherry scheme is properly referred to as OINC (output inclusive nested compensation)

/Smile at joke/
Cherry had a couple of schemes.
Maybe OIC is a limit case of the other but I try to keep them separate for clarity.
Nest Diff. Feedback Loops = NDFL
and
Output Inclusive Compensation = OIC

Best wishes
David

 

[michaelkiwanuka]

OIC is used in NDFL.

 

[godfrey]

NDFL is OINC.

 

[Edmond Stuart]

Ivan, you have mail.

 

[ivanlukic]

Hi Ivan,

Sure, it is important. It means:
"A Nation who bows for tyrants [Adolf Hitler] will lose 'more than his balls', then extinguishes the light"

See: http://upload.wikimedia.org/wikiped...g/800px-Een.volk.dat.voor.tirannen.zwicht.jpg

Cheers,
E.

Serbian scientist Milutin Milankovich (who formulated ice age theory, died in 1958) lectured at some scientific congress. At exact 20 minutes time, given to each participant, he was rudely interrupted by the moderator. Milankovich asked if he could be allowed to finish the sentence, but the moderator said: "No."

 

[jan.didden]

I know. Most scientist are absolutely unable to stick to an agreed time line...

jan

 

[ivanlukic]

Completely offtopic, but Jan and Edmond may know it...

Everybody knows for big British and American white blues bands but one of the best loved here in Serbia was in fact Dutch: Cuby and the Blizzards... Harry Muskee and friends...Desolation... Groeten uit Grollo... Aplleknockers Flophouse... Simple Man...

Heh! I am going out to buy me a beer!

 

[Edmond Stuart]

/OT: cellphones

Even more off topic:
I am also going out to buy me a beer, though for another reason. When I came home, there was an ambulance car parked in front of my home. I asked what's going on here? Nothing, just a false alarm. Then I discovered that my front door banged open by the police because somebody (a she, who else) had told them I might have got a heart attack or so. Why was that? Because, while I was sitting in the train and had left my cellphone at home, I was incommunicado for a few hours. Damage: about 1000 euro. Courtesy of the modern society who's completely addicted to these stupid and heavily misused gadgets and starts to panic when someone is incommunicado for a couple of hours. Cellphones should be banned, all of them and forever.
Amen.

 

[blmn]

Even more off topic:
I am also going out to buy me a beer, though for another reason. When I came home, there was an ambulance car parked in front of my home. I asked what's going on here? Nothing, just a false alarm. Then I discovered that my front door banged open by the police because somebody (a she, who else) had told them I might have got a heart attack or so. Why was that? Because, while I was sitting in the train and had left my cellphone at home, I was incommunicado for a few hours. Damage: about 1000 euro. Courtesy of the modern society who's completely addicted to these stupid and heavily misused gadgets and starts to panic when someone is incommunicado for a couple of hours. Cellphones should be banned, all of them and forever.
Amen.

I think it is a common statement, and wrong almost all the times, that blames the tool and not the user of it.
Cell phone is a very usefull invention, but if someone uses it in the wrong way, isn´t fair to blame the technology. Blame your inconvenient and gossipy neighbor or friend etc.

regards,

 

[Edmond Stuart]

/OT
Agreed, blame the user instead of the tool. But it's the tool that has changed the attitude/behavior of the user.
edit: as for 'should be banned', of course I'm exaggerating a little.

 

[blmn]

/OT
Agreed, blame the user instead of the tool. But it's the tool that has changed the attitude/behavior of the user.

I don´t think so Edmond, your neighbor/friend could use a telephone, or had tried to knock your door or anything else to contact you and call the police/firemen in the same way, with the same results. Actually the cell phone amplifies the illusion of "being accessible all the times", but even in this case everybody knows that the batteries can be discharged sometimes. It´s not perfect as all of us...

regards,

 

[fas42]

Society lurches from one gadget or "thing" craze to the next, over and over again; it's the ongoing desire to always have the latest toy, be in the "in" crowd. Trouble is, people then start to depend on it in various ways before the mechanism is truly mature, with all sorts of mini disasters ensuing ...

As a prime example, just consider MS Windows ...

 

[Bonsai]

Even more off topic:
I am also going out to buy me a beer, though for another reason. When I came home, there was an ambulance car parked in front of my home. I asked what's going on here? Nothing, just a false alarm. Then I discovered that my front door banged open by the police because somebody (a she, who else) had told them I might have got a heart attack or so. Why was that? Because, while I was sitting in the train and had left my cellphone at home, I was incommunicado for a few hours. Damage: about 1000 euro. Courtesy of the modern society who's completely addicted to these stupid and heavily misused gadgets and starts to panic when someone is incommunicado for a couple of hours. Cellphones should be banned, all of them and forever.
Amen.

Hey, look on the bright side. At least there's one person looking after your back!

 

[kgrlee]

I've started a new thread on http://www.diyaudio.com/forums/solid-state/235188-tpc-vs-tmc-vs-pure-cherry.html

• I hope yus gurus will use it as a base point for some of the ‘compensation’ discussions in the threads on Bob & Doug’s books.
• I’m also hoping Bob & Doug will be encouraged to do more ‘real life’ work on ‘pure Cherry’ rather than declare it unworkable.

 

[SY]

And OT political posts have been removed. Please keep things technical and to the topic.

 

[xavirom]

Any edition in Spanish please!!!!!!

 

[michaelkiwanuka]

That resistor was pure dim-wittedness on my part. The original idea was to protect the circuitry if the CCS failed short-circuit; actually very unlikely. The disadvantage is that the voltage drop across the resistor means that when you are variac-ing up the supply from zero the amplifier will not work until the rails reach some +/-9V. By that time damage may have been done if there is a fault. Without the resistor, you can get a visibly good sinewave with only say +/-3V and the operation is much safer. This is dealt with on p511 of the 5th edition. I hope I have by now removed all those resistors.

Douglas, another resistor that I hope you get rid of is the one in series with the base of the controlling transistor in your amplified negative feedback current source.

This resistor needlessley reduces the loop gain local to the current source and, unless I am mistaken, gives no compensating benefits.

Secondly, I fail to appreciate your apparent aversion to using independently biased current sources for the input stage and the second stage. I think two wholly independent amplified negative feedback current sources should be used to eliminate any possibility of modulation of the the first stage source by the second stage source. The extra cost is exceedingly trivial.

 

[DouglasSelf]

I think two wholly independent amplified negative feedback current sources should be used to eliminate any possibility of modulation of the the first stage source by the second stage source. The extra cost is exceedingly trivial.

The extra cost is certainly very small, though I don't know if it counts as trivial. Certainly a perfectly sound idea.

 

[DouglasSelf]

Just to let you all know that the contents of the Sixth Edition of Audio Power Amplifier Design were finally fixed some 10 days ago. It'surprising how late you can leave it these days.

It will be published on 1st July.

My grateful thanks to everyone who made a positive contribution to this thread.