900W H-class PA Amp with Limiter

[NMOS]

Your circuit for 35deg fan on/off is wrong. Use PNP transistors to switch fan (+) to GND. PA protect is for B500 and H900, I just suggest not use stereo PA protect for this powerfull amps.

have changed with PNP,..

coul this work ?

 

[apexaudio]

have changed with PNP,..

coul this work ?

Use 1k resistor from base to emiter of T5, and revert polarity of D3.

 

[NMOS]

Use 1k resistor from base to emiter of T5, and revert polarity of D3.

ok have changed, please check,... is it ok ?

another question,...

Im a little confused.... 22uf in your PA Protect DC protection goes to GND ?

In my schematic C38 goes to GND with 220K and 2n5551, is this right or wrong

 

[apexaudio]

ok have changed, please check,... is it ok ?

another question,...

Im a little confused.... 22uf in your PA Protect DC protection goes to GND ?

In my schematic C38 goes to GND with 220K and 2n5551, is this right or wrong

22uF goes to GND, do you understand this circuit?

 

[NMOS]

22uF goes to GND, do you understand this circuit?

Im try to learning,...please assist me

ok if not GND where..?

 

[apexaudio]

Im try to learning,...please assist me

ok if not GND where..?

22uF goes to GND, sorry for my bad English. 22uF and 150k are DC filter, and if there was DC voltage 2N5551 or 2N5401 conduct and voltage on B,C point of BD241C drop under 400mV, comparator B output goes to +15V...

 

[andrewlebon]

hi apexaudio
greetings can you tell me the function of the 2 diodes
IN4148 CONNECTED TO BASE OF BC550 BC560 IN VERTEX SCHEMATIC
i am getting 56 volts positive dc on output have not connected output
transistors made driver stage till second pair where two 1K OHMM RESISTORS
ARE CONNECTED THE VI LIMITER TRANSISTOR BASE any reason why there is dc output will be very helpful
thanking you
andrew lebon my supply is 70 0 70 dc

 

[apexaudio]

hi apexaudio
greetings can you tell me the function of the 2 diodes
IN4148 CONNECTED TO BASE OF BC550 BC560 IN VERTEX SCHEMATIC
i am getting 56 volts positive dc on output have not connected output
transistors made driver stage till second pair where two 1K OHMM RESISTORS
ARE CONNECTED THE VI LIMITER TRANSISTOR BASE any reason why there is dc output will be very helpful
thanking you
andrew lebon my supply is 70 0 70 dc

Remove R2 (30k) to disconnect DC servo and measure DC voltage on 33V zeners, on resistors R69, R70, R71, R72 (680R), R88,R89 (68R) you must have 1,12V... Go to post #997 and look at the schematic without step driver for test on low power.

 

[andrewlebon]

HI APEXAUDIO
GREETINGS THANK YOU FOR REPLYING WILL CHECK IT TODAY
DO YOU HAVE SCHEMATIC OF DELONG MT 1500 AMP
THANKING YOU
ANDREW LEBON

 

[Djnits]

Use this circuit for stereo, only add DC protect for channel 2. If you have two heatsinks add BD241C(TIP31C) in parallel.
Regards

ok sir thank you, i will try it, you're awsome man

 

[apexaudio]

APEX B2181

 

[apexaudio]

APEX H900 Schematic and PCB

 

[apexaudio]

PSU for H900

 

[apexaudio]

PA protect for H900

 

[FAA]

just finished the pcb. 🙂

 

[irvynejay]

Happy holidays to all

Hello Mile Can is use FES16JT instead of SFA1603/MUR1620
any replacement of BAV21?

H900 is ready will post some picture when all parts are mounted

 

[irvynejay]

mile is it possible to use fr103 rather than bav21??

 

[apexaudio]

just finished the pcb. 🙂

I hope that this version with TL072 step driver will be usefull for diyers who can't find IR2117.
Regards

 

[apexaudio]

Happy holidays to all

Hello Mile Can is use FES16JT instead of SFA1603/MUR1620
any replacement of BAV21?

H900 is ready will post some picture when all parts are mounted

U can use FES16JT and FR103.
Regards

 

[irvynejay]

ok ty mile pcb almost done,,what about irf540 is it enough for h900 or better to use irf2807?