800 Watts approx into 4 Ohms should be feasible, given that U:
-use enough of them in parallel and bridged
-have sufficient cooling
-use a stiff enough PSU
80 Volts peak would give 800 Watts into 4 Ohms. Since you can't go much over 40 Volts supply voltage the last statement would be important.
Why don't you just use a conventional (i.e. discrete) power amp ?
Regards
Charles
-use enough of them in parallel and bridged
-have sufficient cooling
-use a stiff enough PSU
80 Volts peak would give 800 Watts into 4 Ohms. Since you can't go much over 40 Volts supply voltage the last statement would be important.
Why don't you just use a conventional (i.e. discrete) power amp ?
Regards
Charles
better off looking at lm4780 or stk4231v. i know the stk will take up to +75v -75v, (for power of 100 watts with +-50v) its gota be worth a look, plus i personly like the package/pin shape. there are a few higher rated ones in the range, but i cant remember the numbers. there are some triple amp chips as well so parallel three amp then bridge to three more in two packages. its gota be good for getting past 500watts into 4ohms.
or just buy a solid state kit, something like a zeta, or one of the kits from E.S.P. rod elliot does some great stuff at not much money. see you soon, steve.. ..
or just buy a solid state kit, something like a zeta, or one of the kits from E.S.P. rod elliot does some great stuff at not much money. see you soon, steve.. ..
stk was my first diy, at that time, what do I know about heatsinks? 
Got it singing for about 5 minutes and thats it
Rod elliot has something for 500 watts. If can I wanted to push it more.. Im considering using LM3875 to drive additional mosfets or power transistors, since it is already a good sounding chip.
I cant remember who made those stks..
Got it singing for about 5 minutes and thats it Rod elliot has something for 500 watts. If can I wanted to push it more.. Im considering using LM3875 to drive additional mosfets or power transistors, since it is already a good sounding chip.
I cant remember who made those stks..
At these power levels I doubt you´ll have it easier with IC amplifiers than with discretes.
As already mentioned you can go easily up to 200W with the proper circuit from the BP-application note from National Semiconductor and a nice PCB.
For anything more I´d rather build something like Anthony Holton´s mosfet-amplifiers or the optimos from Randy Slone.
or Rod Elliot´s amp. You can get PCB´s for all of these.
Looking at the prices of the LM38XX´s you´ll be probably cheaper off as well.
Hypex models look good, but i think it will cause i big dent on my wallet.
My primary objective here is to push those gainclone chips to its biggest ego. I have some surplus chips that I would like to see them ultilised. Those folks from NSC are very kind
I guess 200W is the ceiling for 3886....
My primary objective here is to push those gainclone chips to its biggest ego. I have some surplus chips that I would like to see them ultilised. Those folks from NSC are very kind
I guess 200W is the ceiling for 3886....
I didn´t write "Completely forget those"...
Talking about about big dents in your pocket:
I think class-d will actually be the cheapest solution.
Zappulse for example is much more expensive than the hypex modules.
The efficiency will also save you some transformer wattage and heatsinks.
Have a look here as well.
Here is an 800W/4R design from National Semiconductor:
http://patft.uspto.gov/netacgi/nph-...,304,138.WKU.&OS=PN/6,304,138&RS=PN/6,304,138
You will need a TIFF viewer (free) and then click on 'images'.
This is a very high efficency design because of the tired power supply. The top tier should be fed with a very lightly filtered supply as the transistor acts as a regulator and removes the ripple.
I would use 6~8 pairs of LM38XX modules for long life, the FET should be a $6 450W IRF type.
With a 900W APT type FET you could build it for 2 ohms and well over a kilowatt.
"One of the advantages of a Class H bridged amplifier in accordance with the present invention is that only two positive supply rails need to be provided rather than the four rails, two positive and two negative, that are conventionally used with Class H amplifiers. Thus, the Class H amplifier of the present invention "tracks" the voltage V1 once the voltage V1 and the bias voltage exceed the mid supply rail V+, thereby providing the efficiency of a Class H amplifier with two less rails. "
http://patft.uspto.gov/netacgi/nph-...,304,138.WKU.&OS=PN/6,304,138&RS=PN/6,304,138
You will need a TIFF viewer (free) and then click on 'images'.
This is a very high efficency design because of the tired power supply. The top tier should be fed with a very lightly filtered supply as the transistor acts as a regulator and removes the ripple.
I would use 6~8 pairs of LM38XX modules for long life, the FET should be a $6 450W IRF type.
With a 900W APT type FET you could build it for 2 ohms and well over a kilowatt.
"One of the advantages of a Class H bridged amplifier in accordance with the present invention is that only two positive supply rails need to be provided rather than the four rails, two positive and two negative, that are conventionally used with Class H amplifiers. Thus, the Class H amplifier of the present invention "tracks" the voltage V1 once the voltage V1 and the bias voltage exceed the mid supply rail V+, thereby providing the efficiency of a Class H amplifier with two less rails. "
May I ask why you would want 800 watts?
Im using 200 to drive my bass drivers and its pretty pointless going bigger unless your going to 1000 watts.
Remember 1000 over 200 watts is only 7dB.
So if 400 watts is quite an easy task then 800 is not really going to give you much more in reality then a 400. Only 3dB, which a human doesnt perceive as much of an increase.
This is the reason I wouldnt get a bigger amp unless it was significantly larger.
The best option is to increase your sensativity.
Im using 200 to drive my bass drivers and its pretty pointless going bigger unless your going to 1000 watts.
Remember 1000 over 200 watts is only 7dB.
So if 400 watts is quite an easy task then 800 is not really going to give you much more in reality then a 400. Only 3dB, which a human doesnt perceive as much of an increase.
This is the reason I wouldnt get a bigger amp unless it was significantly larger.
The best option is to increase your sensativity.
I believe in a school of thought that says in order to drive well down to 15Hz, one must have a a large diameter cone as opposed to long-throw coils.
And as the theory goes, to produce sound at these extremely low frequency, amplifier power increases dramatically(up to several thousand watts actually)
Actually 800 is not my absolute value, I just wanted something really big and around there. Also, I believe it sounds realistic for my level of DIY-ing, instead of 1000+watts.
And the main reason that I looked into 38XX chips is that I have surplus from my projects, and its good to see it ultilised, since its a good chip with many safety functions like overheat, overload protection built in.
However, if there are easier designs I am not really dead fix on 38xx chips
"Ive checked the url. However, I had a hard time understanding what it says I hope you can help.
From what I understood, Nout1 and Nout2 is used to drive circuit in figure2 right?"
No, each figure is a complete amplifier.
The design covered by the patent is in figure 5, all the others are prior art (existing ways of doing things).
"Only 3dB, which a human doesnt perceive as much of an increase."
The contours of equal loudness are 10dB apart in the midrange, that means it takes 10dB more power to sound twice as loud.
In the 30hz~40hz range, however, they are only 3dB~4dB apart.
That means 3dB~4dB can sound twice as loud in the bass.
From what I understood, Nout1 and Nout2 is used to drive circuit in figure2 right?"
No, each figure is a complete amplifier.
The design covered by the patent is in figure 5, all the others are prior art (existing ways of doing things).
"Only 3dB, which a human doesnt perceive as much of an increase."
The contours of equal loudness are 10dB apart in the midrange, that means it takes 10dB more power to sound twice as loud.
In the 30hz~40hz range, however, they are only 3dB~4dB apart.
That means 3dB~4dB can sound twice as loud in the bass.
Use 2 water cooled stk 4050V in bridged mode
Use variable power supply voltages to figure out what is the optimal output/temperature ratio.
I had a firiend that have tried a 2Om load on a STK4050 and it survived. You will need a very good water cooling or your ICs will BURN
I think that you can get over 500 and more wats whith them on a 16 om load. How much the output power will be no 4 Oms of load i cant calculate...
Use variable power supply voltages to figure out what is the optimal output/temperature ratio.
I had a firiend that have tried a 2Om load on a STK4050 and it survived. You will need a very good water cooling or your ICs will BURN
I think that you can get over 500 and more wats whith them on a 16 om load. How much the output power will be no 4 Oms of load i cant calculate...
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