400 watts rms 8ohms audio amp design...help

[darkwind_j]

Darkwind_j, you still have not told us if this is for home use or professional use (PA, DJ, etc.)? And do you need 1 channel or 2 channels?

Sir its for PA.. and 2 channel is all I need but my point is to attain the 400 watts because this is the biggest that I found in stores...Im prefer to used 2 trans,1 /channel crosstalk,and current shotage...

 

[sayang001]

Would it not be a lot cheaper and possible easier to buy one of the chinese PA amp's that flood the market nowadays ?

The DAP Palladium P-700 for example which sells for under 200 Euro here. Spec's say it does 700W @ 8 Ohm briged.

For that money you get a decent case and 3 year warranty, this is impossible to as diy'er

 

[wg_ski]

Yeah - it's a sweeping generalization, but IMO, $200 PA amps are pieces of .... Ones worth buying are more like a grand. $200 buys a 500VA trafo, four outputs per channel, and very little heat sinking. You may as well use an old Phase Linear and put a fan on it.

 

[RocketScientist]

Yeah - it's a sweeping generalization, but IMO, $200 PA amps are pieces of .... Ones worth buying are more like a grand. $200 buys a 500VA trafo, four outputs per channel, and very little heat sinking. You may as well use an old Phase Linear and put a fan on it.

That's funny! Honestly, however, I have to second the pro amp suggestion here all things considered. I wouldn't buy a Gem Sound, American AUdio or Phonic DJ amp but something like a Crown XLS, Samson Servo, Peavy IPR, QSC GX3, Tapco J-1400, or even a Behringer. will probably outperform anything you can build for the same money. All those companies have amps at $200 - $300 US. You can buy them used on eBay for even less.

Another choice is to buy some amp modules like I suggested a long time ago in this thread and bridge them. But you still need power supply caps, bridge, a chassis, heatsink, protection circuits, connectors, perhaps a fan, etc. And things get more complicated if you want balanced inputs, level controls, clipping indicators, high temp shutdown, etc. And, worst of all, bridged into 4 ohms for PA use, it probably *will* blow up. And then you have wasted lots of money.

With the pro amp you get it all the goodies, a warranty, probably more power, and save lots of time and headaches. The cheap pro amps can't match the expensive ones, but they will still probably outperform what you could build yourself for the same money.

 

[h_a]

I think 1kg per 100 W is a very handy rule of thumb that works suprisingly well for toroids:

160 VA 225 VA 330 VA 450 VA
ca. 1,70 kg ca. 2,00 kg ca. 3,40 kg ca. 3,90 kg

The error is generally within 15%.

A good estimate if no rating is on the toroid.

Have fun, Hannes

EDIT: for other cores it might be similar, but I couldn't find data quickly.

 

[darkwind_j]

what is worth of buying.. I want is the passion like an painting artist... besides some Amp which sold in the market are not suited here in my country because of the climate difference with other.. I notice one that we use here one time outdoor is gone to smoke together with speaker...