900W H-class PA Amp with Limiter

[apexaudio]

Originally Posted by wg_ski

It doesn't look like your commutating diodes are on the heat sink.... Are you expecting them to run stone cold? I wouldn't. BTW - which ones are you using? Looks to me like a 2-lead TO-220.

BTW - for all the naysayers - there's nothing wrong with a 5532 in a PA AMP! I use OPA2604's but that's personal preference because I grew up on the LF353. Still doesn't pass the audiophile snob test.

Commutating diodes are SFA1603 TO-220 without heatsink, not cold but no need extra heatsink, maybie small TO-220 heatsink.

[apexaudio]

Originally Posted by event horizon

Well lets just say that seeing how it is built would be interesting I'm sure that a good few people could find use for a powerful & more efficient (than AB) amplifier

I for one am interested & thanks for sharing if you do

I will post schematics. I dont espect any interested about that kind of amplifier in DIY.

[event horizon]

Originally Posted by apexaudio

I will post schematics. I dont espect any interested about that kind of amplifier in DIY.

I'm not sure why not? I bought a Mackie M3000 to drive some bass speakers, that's a 3 stage class H i believe. When the warranty runs out it'll get rebuilt so it uses big heatsinks & no cooling fans

You really don't need anything super quality when used at less than 100Hz in reality, 0.1% distortion should be more than adequate

[powerflux]

Originally Posted by apexaudio

I will post schematics. I dont espect any interested about that kind of amplifier in DIY.

actually, i do. i love high power amps, repair almost only pa stuff or heavy hifi and love to learn more.
reading and understandig schematics is a great way of practical learning

could you post an etch-able pcb layout too?

is it really 900W @ 8? i'd guess at 4 ohms or less with only 4 pairs of 1943/5200..

[apexaudio]

Originally Posted by powerflux

actually, i do. i love high power amps, repair almost only pa stuff or heavy hifi and love to learn more.
reading and understandig schematics is a great way of practical learning

could you post an etch-able pcb layout too?

is it really 900W @ 8? i'd guess at 4 ohms or less with only 4 pairs of 1943/5200..

Power suply 0,+/-60V,+/-120V. THD 0,03% 20-20000Hz on 900W 4 ohms. All new brand amplifier use 4 pairs of 1943/5200 evan for 1900W 2 ohms in their specification. I dont want to go tnat much.

[apexaudio]

My hard drive was death few years ago with all my schematcs. I have no backup, now I must redraw my old schematics. I share all my old schematics, becouse I dont use them in my new products.

[apexaudio]

This is 750W version with single step mosfet IRFZ44. Version is without limiter and balanced input.

[audiomachines]

count me in I am also interested in building the old Apex 900W class H PA amp. cheers

[khalsa]

Hi Apexaudio plz send me copy 900w h class circuit daigram and pcb layout i want build this amp thanks khalsaaudiocenter@yhoo.com

[apexaudio]

H class amplifier output stage, can be used with many VAS.