Zca ....turbo

[sakis]

here we go ...

what is going to happen if we make a ZCA as seen from mark houston but instead one transitor make three for example very carefully matched and three load resistors or othetr type of load and increase the rail voltage ????

probably that will increase the power

what about the rest ???

something like that

[event horizon]

The important thing to do would be fit low value source resistors so that the fets are not left to there own devices, this will force them to match much like emitter resistors would on a transistor.

You'd not need precisely 3 load resistors but a serious increase in power dissipation from the upper load resistor (though 3 in parallel does make some sense ).

[sakis]

ha ha ha ...ok points taken

probably with this to produce 2x15W you will toast arround 150 per chanel ... not very echo ...the question is theoretical ...

then the question is if worth listening to

[wahab]

There s no way producing 15W of audio power from a
24V supply, unless the load is low impedance, but then,
there will be incredibly high thermal dissipation,
not counting a huge THD ratio, since these kind
of amps should rather be called Turbo Distorsion..

[sakis]

HMMM this is what i thought also .... but as i said this is all hypothetical ... i listen music atleast 15 hours a day so there is no question running an amp of this consumption for all day use ....

hei wahab !!! thanks for join in ... ( by the way very nice music !!!!! ) well done !!! i took a look at your web

[wahab]

Originally Posted by sakis

HMMM this is what i thought also .... but as i said this is all hypothetical ... i listen music atleast 15 hours a day so there is no question running an amp of this consumption for all day use ....

hei wahab !!! thanks for join in ... ( by the way very nice music !!!!! ) well done !!! i took a look at your web

Thank you, Sakis,

I also run an amp all day long, if not 24/7, it s low voltage, about +-12V,
so even with a quiescent current of 200mA, it consume just a handful watts;

A circuit is added to reduce the iddle current to 20mA when the output
level is just reaching the amp s noise ,with of course a delay of about 1 minute.

That way, mean comsumation is reduced to very low value...

[event horizon]

If you want to improve the amplifiers effeciency, throw the power resistors away on the drains & make a constant current source You'd again need to set the bias point at whatever current to half the rail voltage.

Or if you can get hold of a large high current (say 100mH or greater) choke & this would make the thing even more efficient (approaching 45% at a guess).You'd not need to bias for half the rail voltage, just enough current for pure class A operation. The amp would then swing nearly double the rail voltage because of the choke.

[destroyer X]

Distorts a lot...but will assemble this one as i have a bunch of unused Fets.

Have you made it Sakis?.... have pictures?

I am thinking..this may be good to keep my coffee hot for all day.

It seems we can use transistors in the place of these expensive resistances.

Picture have Greek imported Olive oil, and some glues to fix boards into metalic enclosures, tape to help to insulate (provisory) something and new batteries for my multimeters..i use to replace each year..exausted or not.

regards,

Carlos

[sakis]

no Uncle Charly it was just one idea

i had very hot chilly supper last night and that results weird dreams in my sleep ha ha ha

[destroyer X]

what a pain.

regards,

Carlos