DIY PSU for car amp (but for home use)

[BNK]

I can get an high end 2x400W car amp (at 14.4V).
Where can I find design/kits for such a PSU using a toroidal transformer?

[dark_avenger]

cheapest easyest way is to get hold of old computer power supplys and hook 2/3 of them together with diods on each....

or

toriodal -> rectifer -> amp

[BNK]

Is it that simple? No problems ahead?
btw. I can get an high end amp 2x400W into 8 ohms, 0.09% thd, s/n 100db for ~300$.

Does it worth it? or you can build a better one for less?

[dark_avenger]

power supplys for car amps don't need to be to complex because they have circuitry built in to regulate power as power from an altinator fluctuates alot.

[BNK]

It's an interesting point as high end car amps are much cheaper than home high end amps.

This amp is rated at 2x400W rms at 8 ohm.
How many PC PSUs and rated at (watts)?
I can get a 500W PSU for 10$.

[dark_avenger]

if u ask around u shoulden't have much trouble finding some second hands ones either cheap or free. computer psu's are rated for all there voltages you will have to look at the sticker on the power supply and cheack the current rating for the +12 rail.

[BNK]

I think I have one or two (~300W).
How many do I need?

I have a rectifier of a gainclone I didn't finish.
As I understand from you, there is no gain of having a toroidal transformer (more expensive)?

[djk]

The 12V outputs on 500W supplies are not good for a lot of watts. The bulk of the power is on the 5V lines. The regulation feedback is usually derived from the 5V lines too.

Just bypass the switching supply on the car amp and feed it what it needs from a 50hz/60hz transformer, bridge rectifier, and caps.

[x84andrea]

it's not a good idea, the car amp have a protection on the psu, and use pwm for produce hi-voltage controlled by a microprocessor, if there aren't 12v the amp don't start or doesn't work well , can you use a big trasformer (800-1kw) at 12v and can you use a big capacitor, in the cars are used not the uF but the farad... 1-2farad is good, but also uses asmaller capacitors, it's too fast!!!!

don't use a 1n4007... use 2-4 large diode (100A is good), ore 2 bridge diode (50a) but isn't recommendet.

the power is rms or max?

[BNK]

Originally posted by x84andrea
it's not a good idea, the car amp have a protection on the psu, and use pwm for produce hi-voltage controlled by a microprocessor, if there aren't 12v the amp don't start or doesn't work well , can you use a big trasformer (800-1kw) at 12v and can you use a big capacitor, in the cars are used not the uF but the farad... 1-2farad is good, but also uses asmaller capacitors, it's too fast!!!!

don't use a 1n4007... use 2-4 large diode (100A is good), ore 2 bridge diode (50a) but isn't recommendet.

the power is rms or max?

The power is rms.
This is the amp:
http://www.linearpower.com/lpspecs.html
Model:2202 moded to 2x400W at 8ohm.
The site contains description of the amp.

Can you recommend a PSU kit that I can use with that?
Do I need a toroidal transformer or a "regular" one is good enough?
Do I need to add a car cap at the front?