1000W Simple PA Amplifier

Exactly......

Many diyers love old school amps with classic design without cascodes or class H operation, just simple current mirror VAS and EF output stage :)

A simple current mirror VAS and EF output stage will be exciting and diy freinds will love and have fun building this new APEX amp design (maybe with 4 pair for initial build using lower rail voltage then can be upgrade with few versions later into a max pairs accordingly) that will fit everyone needs.

Regards,
 
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SOA problem

What about SOAR of a 9pair 1943/5200 stage when operating from a 110Vdc supply?

You are right. There is a very clear SOA problem. See attached picture.
Simulations show 400W to 1000W resistive load @4R.
SOA worsens with real reactive load. :confused:
 

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I use my usual Pmax guide.
Pmax ~ total BJT output stage wattage divide by 5 or 6.
Since the 1943/5200 have terrible high voltage SOA, I would use divide by 6 if I can keep them cool enough.
9pr of 150W devices = 2700W.
Pmax ~ 450W if kept adequately cooled.

That's why I raised the comment, particularly since Apex is suggesting it for PA duty.
 
I use my usual Pmax guide.
Pmax ~ total BJT output stage wattage divide by 5 or 6.
Since the 1943/5200 have terrible high voltage SOA, I would use divide by 6 if I can keep them cool enough.
9pr of 150W devices = 2700W.
Pmax ~ 450W if kept adequately cooled.

That's why I raised the comment, particularly since Apex is suggesting it for PA duty.

MJL21195/96 or MJL4281/4302 will be ok and 1N5408 for back EMF.
 
You can use this simple DC protection with 40A relay (12V for car)

It is a reoccurring theme trying to use a Low Voltage DC contact rating ( 14VDC) to construct a Speaker protection circuit. 110VDC@40ADC with the suggested relay is impossible, and this is a benign scenario. View the accompanying graph of a typical Automotive relay contact capability before experimenting with welding techniques.
 

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It is a reoccurring theme trying to use a Low Voltage DC contact rating ( 14VDC) to construct a Speaker protection circuit. 110VDC@40ADC with the suggested relay is impossible, and this is a benign scenario. View the accompanying graph of a typical Automotive relay contact capability before experimenting with welding techniques.

Thanks for warning, I see 12V/80A relay in CREST CA18 and get this idea. I will try this relay with 220vac and 1500W heater for test :)
 

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