high performance 25W PowerAmp

[hbtaudio]

bad enginering from the start, the only reasonable approach that would be a testimony
of good enginering capabilities is to keep it in the museum of electronics horrors.

That's exactly how it is. We should let this thread rest now - in peace.

 

[bucks bunny]

By the way: I have not yet tasted the flavor in any recipe;-)

There is much more you did not taste yet. Physics, electronics, just to mention a few

 

[hbtaudio]

Exhumation of the corpse requested
L. Stellema meets Steve's Krill



What if' the IPS-VAS combination were aligned as follows?
We could simply add a really good diamond buffer at the end, as in the "Krill example", couldn't we?

greetings,
HBt.

 

[anibal]

This configuration is known as "Borbely-Lender" and it is excellent!

 

[Zohaib Ahmad]

The day before yesterday I stumbled across an article by L. Stellema (University of Sydney, Department of Aeronautical Engineering & Electrical Engineering).
Published in September 1980, it's a pretty well-designed hi-fi amplifier with impressive specifications.

in advance
the final stage of the small, clever amplifier - All transistors are mounted on a common heat sink!

Good

 

[wahab]

Exhumation of the corpse requested
L. Stellema meets Steve's Krill



What if' the IPS-VAS combination were aligned as follows?
We could simply add a really good diamond buffer at the end, as in the "Krill example", couldn't we?





View attachment 1316682



greetings,
HBt.

This VAS topology is weird since you can switch off the BC327only if its emitter resistance has enough voltage drop
because otherwise you ll need to saturate the 2SC2240, wich is not possible since its base voltage cant exceed
its collector voltage, and a big enough emitter resistance for the BC327 will eventually limit its gain while creating
an annoying frequency pole.

Now replace the 2SC2240 in the VAS by a 2SA970 in common collector and you ll get the usual enhanced VAS that
work flawlessly, in all other cases that would be an exhumation just to beat even more a decidely dead horse.

 

[hbtaudio]

In other words, completely in the direction of the original "Krill" design by Steve Dunlap, only designed for 25W. Oh, I could quite like that.

Or is this idea also not yet fully developed, as well as
the “Borbely-Lender meets Mr. Diamond” pitch?

 

[hbtaudio]

without load - PowerStage

clipping approx +18,6V

 

[hbtaudio]

more current and inverting

clipping approx +8,6V now!

 

[hbtaudio]

Now replace the 2SC2240 in the VAS by a 2SA970 in common collector and you ll get the usual enhanced VAS that
work flawlessly, in all other cases that would be an exhumation just to beat even more a decidely dead horse.

It obviously looks like that, almost a lost case.

 

[wahab]

Only the skeleton will remain that you ll still be beating the poor thing, that look like vengence.

Other than this you should put a reference for each transistor, Q1, Q2 etc, that render all eventual explanations
much easiest, if there s a any need.

 

[hbtaudio]

No, that is absolutely not necessary or even essential .

 

[hbtaudio]

Only the skeleton will remain that you ll still be beating the poor thing, that look like vengence.

Other than this you should put a reference for each (...)

Is this better???

 

[hbtaudio]

The new IPS-VAS can be controlled completely symmetrically in terms of voltage. It does not oscillate and only overdrives at loads (RL) below 3kOhm.
What is the input resistance of the Krill or the Stellema's Diamond-Outputstage, the buffer?

 

[hbtaudio]

I take the liberty of modifying the diamond.
Will that work? Who needs to be thermally coupled with whom?

 

[wahab]

They will be thermally coupled at no more than ambiant temperature after they took their liberty
for an inherent big kaboom...