900W H-class PA Amp with Limiter

no!i don't have an intention to drive the speaker at its full capacity. and besides the amp is not intended to drive specifically to that speaker. i decided to increase the rail at +-20v, and that would give HV of +-145v and +-155v for VAS. in this case, there's no way the amp can produce as much as speaker specs. this would give around 1300@8ohm at clipping, so its safe.
this amp is for mobile purposes so it needs to be high power.

for mile, what is the current set at vas stage on your vertex amp?..
 
i'd finished cascoding two transistors at vas stage of h900 based on ba2000 and it work fine. setting up vas current at 10ma, the cascode bias resistor between the 2 base of mje340/350 is 180k instead of 220k,this would divide the voltage rails equally to all pairs
now my amp has a vas rail of +-150v separated, MV=80v and HV=140v respectively. i plan to use 3step driver but it seems i have to rewind my transistors and add another set of board. so i decided to add more output transistors and mosfets to compensate more power. the mosfet was 4pairs of irf2807

regards..
 

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Hi rohin greetings,
I build one channel h900 and 750va transformer sound very loud and clear. Its produce more heat my rail 100-50 dc offset .3ma .how to buy a power amp case

hi, for home use you can use any transformer thats not a matter.for case go to iron box maker shop(electric panel builder) and give them dimension they will make.heat can come for several reason if possible post pictures.
 
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Protect PCB size: 80x75mm
Hi Mile,as this protection board is against the overload, d.c present on out(speakers)
and overheat ,what is the lower d.c v (in speaker out)for protect activation,what is the level on pro input for protect activation?
I want to know these levels for testing this protection board stand alone without connection to an amplifier.
2x18v a.c is from a separate transformer?
Can you post a wiring diagram with an amplifier?
 
Apex PA protection

Hi Mile ,i beleive that is a wrong polarity diode in this board.
Please have a look at this acording to this schematic.
I have test this and some measurements posted here just in case helping others
 

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