from the net

netuddki · 29th November 2008, 07:07 PM

hi!

from the net

mosfets · 29th November 2008, 08:49 PM

Without validating or checking the schematic for errors, in general I would say this design as it is could deliver 600 watts into 4 ohms. But I'm just making generalizations.

nigelwright7557 · 29th November 2008, 09:35 PM

Quote:

Originally posted by mosfets
Without validating or checking the schematic for errors, in general I would say this design as it is could deliver 600 watts into 4 ohms. But I'm just making generalizations.

The pdf clearly states 1200 watts.

netuddki · 29th November 2008, 09:37 PM

Hi!

if you see errors please tell me!

darian · 29th November 2008, 09:59 PM

I agree about the power available : Max 800W into 4 ohms in theory, fo real more around 600W with the mosfets voltage drop and the non perfect power supply in real life (10 to 15% of voltage drop at peak current).

wakibaki · 29th November 2008, 10:10 PM

Quote:

Originally posted by nigelwright7557
The pdf clearly states 1200 watts.

The oracle has spoken.

w

mosfets · 29th November 2008, 10:23 PM

Quote:

Originally posted by netuddki
Hi!

if you see errors please tell me!

Have you tried it out in a simulator? Linear Technologies offers a free simulator from their web site. BTW the circuit does look nice. I'm not certain if I have ever seen a VAS stage quite like this one. I may try to simulate for my own curiosity.

darian · 29th November 2008, 10:43 PM

This is nothing too fancy, no real need to simulate it. The input stage is super classical and the VAS is just a cascoded one, cascoded with a mosfet, ok, more usually it is a bjt. Actually a bjt would be certainly better for cascoding from a pure technical point of view. Anyway, this has been done before and will be done later... To me it is another non inventive design... With a miscalculated power max as a cherry on the cake.
Nevertheless I am quite sure it would perform pretty well, like all of his kind.

Regards

darian · 29th November 2008, 11:24 PM

The max power is given by (max voltage)square/R/2 in a push-pull power amp as far as I know electronic. But you may think what you want...
The max voltage is less than the PSU because it lowers when loaded and the output transistors are not perfect shortcut at full power. This is the theory, after, it could be even less power if the fanning is so insufficient that the output transistor blow away before the theorical max.
Sorry but I think I am pretty right on that one! Even with more transistors, 80v will only get you that far!

darian · 30th November 2008, 12:15 AM

Of course it depends on the load!!!
Let s say you have 8 ohms and run 3 amps at peak to reach a peak of 24v and your power supply is 24v, you clip. At 4 ohms you can run run twice the current in there before it clips. And when you go too low in load the peak current is so high that you blow up the transistor...
I am a little surprised by your assertion...

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29th November 2008, 08:49 PM	#2
mosfets diyAudio Member Join Date: May 2008	Without validating or checking the schematic for errors, in general I would say this design as it is could deliver 600 watts into 4 ohms. But I'm just making generalizations.

29th November 2008, 09:37 PM	#4
netuddki diyAudio Member Join Date: Feb 2007 Location: hungary	Hi! if you see errors please tell me!

29th November 2008, 09:59 PM	#5
darian diyAudio Member Join Date: Mar 2006 Location: Paris	I agree about the power available : Max 800W into 4 ohms in theory, fo real more around 600W with the mosfets voltage drop and the non perfect power supply in real life (10 to 15% of voltage drop at peak current).

29th November 2008, 10:43 PM	#8
darian diyAudio Member Join Date: Mar 2006 Location: Paris	This is nothing too fancy, no real need to simulate it. The input stage is super classical and the VAS is just a cascoded one, cascoded with a mosfet, ok, more usually it is a bjt. Actually a bjt would be certainly better for cascoding from a pure technical point of view. Anyway, this has been done before and will be done later... To me it is another non inventive design... With a miscalculated power max as a cherry on the cake. Nevertheless I am quite sure it would perform pretty well, like all of his kind. Regards

29th November 2008, 11:24 PM	#9
darian diyAudio Member Join Date: Mar 2006 Location: Paris	The max power is given by (max voltage)square/R/2 in a push-pull power amp as far as I know electronic. But you may think what you want... The max voltage is less than the PSU because it lowers when loaded and the output transistors are not perfect shortcut at full power. This is the theory, after, it could be even less power if the fanning is so insufficient that the output transistor blow away before the theorical max. Sorry but I think I am pretty right on that one! Even with more transistors, 80v will only get you that far!

30th November 2008, 12:15 AM	#10
darian diyAudio Member Join Date: Mar 2006 Location: Paris	Of course it depends on the load!!! Let s say you have 8 ohms and run 3 amps at peak to reach a peak of 24v and your power supply is 24v, you clip. At 4 ohms you can run run twice the current in there before it clips. And when you go too low in load the peak current is so high that you blow up the transistor... I am a little surprised by your assertion...