Lineup's Poetic Wisdom

[lineup]

.


When did you last visit Bob's Homepage
Cordell Audio - CordellAudio.com

Bob's Place
- it has much more stuff than lineup audio
which per say
doesn't have to mean it is higher average quality of web stuff.

Just because Bob & Me, Lineup use .com = commercial
this doesnt have to imply we are out to sell, every minute of the time!
I ask, Isnt this board at
www.diyAudio.COM


Me, Lineup, doesnt sell a thing.
I give away 80% of what know. Maybe 90%.
This is my business IDEA.
You will say:
... will not make you rich and give any money,
my poor old chap

that's right, my friend
you've got it
is all a part of my life policy
to stay 'a poor boy'
... very 'poor' by your standards
... some standard
... hmm


/linjoy - June 2007
Top Of Europe







---------------------------------------------------------------------------

Cordell Audio
http://www.cordellaudio.com/

Listening & Measurement Workshops
Home Entertainment Show May 11-13, 2007

Workshop #1
Amplifier Measurement Clinic

How are amplifier measurements done, what do they mean, and do they have any real value? This amplifier measurement clinic will show attendees how audio power amplifiers are measured and which measurements are important. Power amplifiers will be measured in a fashion similar to those published in Stereophile equipment reviews. This clinic will be conducted by Bob Cordell, who is an amplifier designer ..... etc etc

Workshop #2
Amplifier Listening Comparison

Few audiophiles have ever been able to participate in a real-time, level-matched comparison of two power amplifiers driving the same speaker system in the identical acoustic environment. Amplifiers will be auditioned in real-time listening comparisons ....... etc etc

Workshop #5
The Peak Power Demands of Well-recorded Music

This attention-getting demonstration
may make you think twice
about how much amplifier power you need.
You will be able to see in real time the very high peak-to-average power ratio (crest factor) of music while you are listening to it. The high crest factor of well-recorded music can place very high peak-power demands on a power amplifier even at modest listening levels ... etc etc

Bob Cordell, 2007 years after the lord - our true master of these ages

rich or poor ... you be the judge

.... your verdict, your conclusion,
will tell more about You, YourSELF,
than reveal much about my audio friend Bobby
.... some standard ....

... any way,
bob cordell audio deserves your visit - lots of good stuff,
for us interested

[lineup]

Originally posted by estuart

lineup, please and

Originally posted by PMA


Yes.

Originally posted by G.Kleinschmidt

Oh, c'mon. That was the funniest thing I've read in ages. I want some of what Lineup is smoking.

Cheers,
Glen
PS
Bob looks like he needs to go on a diet.

in my book:

when somebody cant argue your statement
but resort to other perifer and Off Subject comments,
like some offensive smileys
then
... you are probably close to something to hot, essential, eve sometimes close to true reality


i was one time critisized
by a few of 'his blind followers'
for a post i had directed to Nelson


Nelson came in later.
The Only thing the Only One replied to me was:

- How right you are

... at least I think, he added his usual COOL SMILEY
It made my day!
All theose other negative, hostile posts were suddenly swept away, forgotten.

-----------------------------------------------------------------------------------


Bob Cordell, same age as me and Nelson and 'dxamp' Carlos' (I am actually a few days older than Nelson)
can take more than some 'crazy lineup thoughts'
and maybe even contemplate or add a new perpective to things, in their mind

Bob Cordell, by all records I have found,
a friendly a very nice chap
... has probably got more wisdom, than some have,
and can see my post, for what it was, for what it is worth

At The Core an act of concern.
And not out to be destructive to anyone's Life.
Or Activities.


Regards, as usually,
from Sweden
and
Lineup





==========================================
... all can not love or like lineup, i know (That's Life ...... !!!!!)

... but 90% will read his thinkings and some schematics, too
... and once in a while learn a new thing, or 2 things

... 90% of topic readers are guest visitors - not registered, all quiet
... the silent majority, they be my true judge

... but most will in the back of their room, in private, count with lineup
... if not today, so before 'day is done'
... you can not do your math of life and ignore a basic number: 1,2,3 ..

you can count on me
you've got a friend - grave concern is

[lineup]

Originally posted by Workhorse

Hi BOB Cordell,
Nice see another lover of Vertical Mosfets!

Majority of Diyers here on forum are very much inclined towards the good old/new BJT designs and they resist Vertical Mosfet designs because implementing them require much more precised skillset to do the job in excellent manner...
Only some of the few designers have this under their possession....

As far as I know
Vertical Mosfet amp designers are
Nelson Pass
Bob Cordell[nice meeting you]
Greg Ball
Anthony Holton
and me too

K a n w a r

Yes, I agree Kanwar.
It isnt fair, that so few want to use VERTICAL FET.

Finally we have got some clever guys, that can tell us
things isnt as bad as they say, with IRF Devices.

Of course is nothing wrong, with using one or two BC550C
or even one MJL21194 and whatever BJT bipolar.
But why indeed keep on with such old techniques
... when we have our new modern Field Effect Transistors.

Face it, it would be like go back to 1950-60
and start trying to make Audio HIFI with Valves, electron tubes


MOSFET, HEXFET and JFET
can make both power & hifi
better than anything else

... if you know howto, that is



Regards lineup
.. tubes and bipolars were great & best just yesterday
.. but there is a new today & a new tomorrow, in most cases (mornings)

[lineup]

Originally posted by Bob Cordell

Let's build a 100 W Class A amplifier from MOSFETS.

It must support 40V pk and 5A pk into an 8 ohm load. Lets give it 44V main rails.

The Class A idle bias must be 2.5 A.

Lets use 5 pairs of MOSFET output devices, each carrying 500 mA of idle bias and each dissipating 22W at idle.

The dynamic source impedance of each MOSFET is about 250/500 = 0.5 ohms. The five upper devices in parallel will yield a net upper Rs of 0.5/5 = 0.1 ohms. The bottom five devices will do the same, bringing the total open-loop output impedance at idle to 0.05 ohms.

At a peak current of 5 A, each of the upper transistors is at 1 amp with an Rs of 0.25 ohms. We have five in parallel, so we get an effective net Rs of 0.05 ohms. To first order, this is the same as at idle bias. Of course, there will be wiggles in between, and this approximation is only that, but the point is that the output stage net transconductance, variations of which will cause distortion, will actually vary very little with signal in this Class-A arrangement.

In any case, the variation in net 1/gm is certainly less than 0.04 ohms over signal. This is less than 0.5% of the 8 ohm load, suggesting in very rough terms open loop distortion on the order of less than 0.5%. Now we put 40 dB of NFB around it and we are at 0.005%, and actually probably quite a bit less.

Cheers,
Bob

Bob or maybe better friend G. Kleinschmidt

Which post is the schematic?
I have searched, but found .... nothing.
I have asked for what transistor we should use, before.

I am still waiting for something constructive produced by this topic.
Something useful,
anything to, at least, start working from for diyAudio members

The conditions to make a good BJT/MOSFET are here:
.... some of the sharpest and finest audio-brains ever lived in the States
and a few above average from Europe/Japan/India, too.
--------------------------------------


Bottomline:
Abstact tennis playing
and exchanging interesting thoughts back and forth
is all nice.
But what the use, besides the social club feeling and that .....
Only doing Who-Can-Say-the-Correct-Words-Games-Mingling
with the Audio authorities and all this is not enough for me.

Come on!
Let this thread get its own Amplifier project.
Bob's sugest was a good one .... Start from there ..



Regards lineup
- by one (1) fruit, we know a tree can produce
- if not, we better burn it down, it is good for nothing

[Variac]

We have decided to give lineup a place where he can post his musings, which some enjoy, without interrupting threads, which many don't enjoy when he is off-topic.

Variac

[destroyer X]

... to accept 3.5 Megabytes audio message.

I have an important, and urgent, audio mail message to you.

Was send and returned from your standard Opera Mail E mail adress.

Also i suggest you to provide us, this information to contact you in our forum, as everybody does.

please goto:

panzertoo@yahoo.com

And provide me conditions to reach you...very urgent.

regards,

Carlos

[peranders]

Originally posted by lineup
Just because Bob & Me, Lineup use .com = commercial
this doesnt have to imply we are out to sell, every minute of the time!

Mr Liney, most top domains has little to do with the content of the website. .com can be used to anything but some top domains have certain requirements like .eu for instance.

[destroyer X]

It is an MP3 audio file...size is 3.5 Megabytes.

Can you please, give me the honor to receive your E mail adress.... the one able to receive those files without send em back to me.

goto:

panzertoo@yahoo.com

regards,

Carlos

[lineup]

hi
another post where i try to add some extra values
to our community board
SEE MY ATTCHMENT.
I call this one
Donate Some Blood
... its a matter of life for your own child


happy regards to you all
- but no empty posting with zero substance
from
ya brotha .. lineup
__________________________________________________ __



Web references, links:


American Red Cross - Give Your Blood .. Now!


http://www.givelife2.org/aboutblood/

[GK]

Originally posted by lineup
hi
another post where i try to add some extra values
to our community board
SEE MY ATTCHMENT.
I call this one
Donate Some Blood
... its a matter of life for your own child


happy regards to you all
- but no empty posting with zero substance
from
ya brotha .. lineup
__________________________________________________ __



Web references, links:


American Red Cross - Give Your Blood .. Now!


http://www.givelife2.org/aboutblood/

Wow! There are hot chicks like that at the Red Cross blood donation center?
I'm going tomorrow (won't give away too much blood though, I'm hoping I'll need little reserve for something else.......)