simple class d sub amp

[jamie1107]

hi
im new to the world of class d amps so forgive my ignorance
i have built a few gain clones and valve amps but now i would like to try building a class d amp for a sub i have built ideally between 200-400 w rms into an 8 ohm load
does anyone have a simple schematic and psu for my project the more basic the better
many thanks

 

[MikeHunt79]

try the 41Hz.com amp2 kit....

600W into 8 ohms bridged... Probably around 400W at 0.1% thd.

 

[luka]

Hi

I don't know if you will be able to make one yourself and since kits from 41Hz aren't that expensive.

Amp2 is sure the way to go I have one and I am very happy with it, and you could push it to ~850w into 8 with rails of +/-60v

 

[MikeHunt79]

Hi

I don't know if you will be able to make one yourself and since kits from 41Hz aren't that expensive.

Amp2 is sure the way to go I have one and I am very happy with it, and you could push it to ~850w into 8 with rails of +/-60v

What's the difference between the amp2 and amp8 kit? I don't have either right now, and if I can run an amp2 with 60v rails it seems pointless going for an amp8....

 

[theAnonymous1]

AMP8 has more output FETs for lower impedance loads. If you tried to run a 4R load on the AMP2 with +/-60v rails........

 

[noah katz]

"you could push it to ~850w into 8 with rails of +/-60v"

? I calculate that 60V gives 225 W into 8 ohms.

Maybe you meant 2 ohms?

 

[theAnonymous1]

I think he meant BTL. I was also thinking BTL with my above comment.

 

[luka]

Hi

Bridge, BTL since you need it for sub, you need only one channel, or in this case BTL

 

[luka]

AMP8 has more output FETs for lower impedance loads. If you tried to run a 4R load on the AMP2 with +/-60v rails........

Watch me , it is not a problem, 22A current limit will give you over 900w into 4r, and +/-60v over 800w into 8r, cooling should be good

 

[MikeHunt79]

AMP8 has more output FETs for lower impedance loads. If you tried to run a 4R load on the AMP2 with +/-60v rails........

Ahh, ok. I haven't built either yet, but the amp8 sounds like it is the one to go for me.

 

[luka]

Hi

It all depends on what you will have, AMP2 is smaller and better for 8r in bridge, or 4r stereo, Amp8 for bridge and 4r load, but much bigger

 

[MikeHunt79]

I plan to drive 4 ohm loads, so even tho it is larger, it will still give a lot of power for it's size. being class D.

 

[luka]

Hi

That is for sure, it has a lot of power, if you can supply the amp right...how do you plan to do that?

 

[MikeHunt79]

Well, I already have some nice 100v 10000uf caps, so I'm probably just gonna get a huge 1000va toroid and a rectifier.

 

[AntonZ]

You may want to include some sort of soft start feature. Just plugging in a 1000VA toroid with a rectifier and a huge amount of capacitors is likely to blow fuses in your house due to the inrush current (very high current at startup when the capacitors are being charged from null).

 

[MikeHunt79]

You may want to include some sort of soft start feature. Just plugging in a 1000VA toroid with a rectifier and a huge amount of capacitors is likely to blow fuses in your house due to the inrush current (very high current at startup when the capacitors are being charged from null).

Thanks - I do plan to go for a SS circuit. I guess it will also make things easier on the caps and toroid.

I don't even have the toroid yet tho, this amp's been on the back burner, as I haven't built the speaker enclosures yet for the drivers that this amp will power...