request high power amplifier

hi
I am milad . I am come from iran . I am not good english language .
I am farsi language . I am Collegian electronic in iran , I want
a 400 or 500 or 600 or 1000 Watt R.M.S high power audio amplifier stereo
for project university . I does search on the forums and find circuit
PA-600 but there was write : might be an error or two in the drawing or parts
list ??? I want build a circuit high power audio amplifier 400 - 1000 Watt R.M.s
stereo for project university please help . ( please a working circuit and
not error ) I need to your help.

babye
 
mohandes_milad said:
hi
I am milad . I am come from iran . I am not good english language .
I am farsi language . I am Collegian electronic in iran , I want
a 400 or 500 or 600 or 1000 Watt R.M.S high power audio amplifier stereo
for project university . I does search on the forums and find circuit
PA-600 but there was write : might be an error or two in the drawing or parts
list ??? I want build a circuit high power audio amplifier 400 - 1000 Watt R.M.s
stereo for project university please help . ( please a working circuit and
not error ) I need to your help.

babye


Hi Milad,

Welcome to the forum !

Well, the power range you are looking for your project is pretty high. As far as I am concerned, projects in this forum have, mostly, a lower power range. I can't recommend one project for you either but if this is your first amplifier project I would suggest going lower on power requirements. You can find a lot of nice designs around here ranging from really low values up to 200 W.

Managing high power levels requires some experience.

Sorry for not helping much.

João Pedro
 
400W at 8 ohms already is quite an ambitious project since supply rails at idle would be approx +-95V and standard output devices would be used at the limit of their SOA.

Bridging, class G and class H are two alternatives in order to get higher output powers in a practical way. Note that class G and class H circuits are somewhat more complex than conventional ones, so developing such an amplifier from scratch may take several months and hundreds of dollars in components.
 

kASD

Member
2004-12-25 12:24 pm
N/A
rajeev luthra said:
The ZEETA is a high power amp


Oh , Rajeev, its ZETA not ZEETA, its quite sure that its an high power design...

Originally posted by EVA 400W at 8 ohms already is quite an ambitious project since supply rails at idle would be approx +-95V and standard output devices would be used at the limit of their SOA.

Why not use Large SOA 250V Mosfets such as IRFP264 and get rid of these Bipolars 5200/1943

regards,
K a n w a r
 
What's the amp for?

If the amp is for PA work then this cct would be suitable. I have built the amp shown as a party system. It runs on +/- 90 volt rails and it delivers just over 650 watts into 4 ohms using 10 IXFH26N50's per channel (5 per rail).

With 4 extra FETS per rail, and some small cct modifications 1000 watts into 4 ohms is acheivable.

The power supply as suggested already will be ambitious and will look like;

1. At least a 3KVA transformer with 2 x 80 volt (under load) AC windings. This will give you DC rails of about +/- 110 volts.

2. At least 100,000 uF of capacitors per rail per amp module.

3. 50 amp bridge rectification per amp module.

4. A lot of other heavy duty stuff.

Plus a budget of over $1,000US if you purchased everything new.

If you build it, please post your results.

PS. Of course you could always build a Class D .....might be cheaper.

Cheers
 

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I have a circuit somewhere for a commercial amp that claims 600W from four pairs of 2SK149 and their complement, all driven from a 5534 (no other silicon apart from the protection circuit)! They only have 4700uF smoothing, and a 2 channel amp runs off a single 1kVA transformer.

It probably sounds awful outside of its natural environment (a rave), I mean, those fets' gates have a lot of capacitance for the poor little opamp to charge up, but it's reliable and was manufactured for several years by the factory next door. The output devices' sources are grounded so no need for insulating washers. I thought that was a neat trick.

If anyone's interested I'll dig it out.
 

funberry

Member
2005-08-17 3:23 pm
Quasi
Thanks for that quasi-complementary amp schematic.

It's really awesome because in using all N-channel MOSFETS, it frees me from the highly arduous and expensive task of finding complementary power MOSFets.

Anytime you need to use complementary MOSFETS, you're at the mercy of a few suppliers, obscene prices, and a potential victim of all the world's counterfeiters.

Long live DIY.

Adrian
 

funberry

Member
2005-08-17 3:23 pm
Milad:

I want a 400 or 500 or 600 or 1000 Watt R.M.S high power audio amplifier stereo for project university

You should go to more conservative university...


Point 1: If you need 1000W why channel it through 1 amplifier?

Use 4 x 250W. This way, you can use 250W speakers (which you can find) not 1000W speakers (which you can't find). You won't need to use 6 gauge wire for the speakers. And you distribute your safety risk over 4 amps, not 1. More speakers driven by lower power, means more surface area moving, so it has to move less far, putting less stresses on the drivers.

Point 2:

In practice over 95% of power hadled by large systems is for bass content (under 100Hz). So your 1000W system will likely need to drive 950W of bass, and 50W of everything else.
A subwoofer amp can do a much better job of pumping out power if it doesn't have to reproduce high frequencies. You won't worry about harmonic distortion, frequency response, or slew rate.
Use 4 amps for the bass, and 1 very high quality 50 W amp for above 100Hz.

When bands perform in concerts and deliver 5,000 -10,000W of sound, did you think it comes from one amplifier? Through one loudspeaker?

Reality check.

Adrian
 
I agree in principle with funberry though his (hers?) percentages may be inaccurate.

I would run a tri amp system with 600 watts for bass 200 watts for mid and about 100 watts for treble. This would give you a fantastic setup and each amp would weigh a lot less.

You could build frequency range specific speaker boxes that would also weigh less than full range units.

Cheers
 

funberry

Member
2005-08-17 3:23 pm
Quasi

I'm still grateful to you for providing that quasi-complementary amp design ( I have so many N-channel MOSFETS! ).

You're right. Those percentages are very rough estimates.

In my particular case, because I insisted on driving 2 woofers and 2 subwoofers, with program content below 50Hz, to make the floor and walls tremble, it is taking a lot of power to move all of this -about 500W. At the same time, 25Watts of mid and highs (got some piezzo tweeters) is totally ear-braking. So my percentages may be more than 95% to bass, while others may be 70/30.

And because I de-emphasize the 75Hz-200Hz band (to remove muddy bass), it further lightens the demand on the smaller amp.

(I get the sub-50Hz content from a sub-harmonic synthesizer I bought in Holland).

extra complexity of power supply

I'm a proponent of getting 500W with 5x 100W amps each driving a 100W speaker, each with its own power supply.

To derive this power from 1 amp /1 power supply would mean +/- 100V rails, and frankly, I don't want to go there. (not to mention obscenely expensive cpacitors)

Let's face it -- this is home-made stuff, bud; It could blow in my face anytime.

and hf distortion and possible cross conduction

Each amp drives its own speaker. This is all happening at bass frequencies. I'm not sure I know what you mean. Please explain.
Maybe there's something I overlooked.

Thanks

Adrian
 
Caution

On page 1 of this thread I posted an amp schematic.

This cct is really only suitable for rails up to 90 volts (plus input & driver rail of 100v). This is beacuse the FETs specified for T7 & T9 are only 200 volt devices and T7 carries nearly the full rail to rail voltage

If 110 volt rails are used (plus 120v for the input & driver rail) then higher voltage FETs must be used for T7 & T9.

If these FETs can't be found then changes to the second stage can be made to accomodate the existing FETs.

Cheers
 
funberry there are a lot 1kW PA drivers out there..
I use 2x 1200W amp with 105V rails to drive two 1kW bc speakers woofers and it performs very well if you forget about heat it produces at full power (I used passive cooling;)).

Here`s the schematic althrough I know that it isnt perfect but I didnt realise that until I had the amp assembled, but it worked well in these two years even when loaded with 2 ohm loads.. And I used 2x10 output transistors per channel.

http://www.diyaudio.com/forums/attachment.php?s=&postid=50335&stamp=1029019783