Help the Apex 550W Class-B?!

radio · 06:13 AM

Hello all!
I want this amplifier 550W class-B to be processed into kalass-AB, and instead of diodes D3 (1N4148) and D4 (1N4148) for the bias, to put the transistor for bias, ... such as BD139 or similar?

That's why people help you do that changes the pattern of this amplifier?
thanks

NMOS · 9th July 2011, 11:33 AM

Quote:

Originally Posted by radio

Hello all!
I want this amplifier 550W class-B to be processed into kalass-AB, and instead of diodes D3 (1N4148) and D4 (1N4148) for the bias, to put the transistor for bias, ... such as BD139 or similar?

That's why people help you do that changes the pattern of this amplifier?
thanks

please check amplifier basics knowledge....

this amp is working in class AB

but you can add class AB +B for more output power

Tekko · 9th July 2011, 01:44 PM

Just replace the diodes with a VBE multipler, its really that simple.

radio · 9th July 2011, 05:07 PM

Quote:

Originally Posted by NMOS

please check amplifier basics knowledge....

this amp is working in class AB

but you can add class AB +B for more output power

Mr. Mile Slavković said two diodes (2x1N4148) the amplifier operates in class-B (see the schematic as written on the top left?)

Cheers

radio · 9th July 2011, 05:09 PM

Quote:

Originally Posted by Tekko

Just replace the diodes with a VBE multipler, its really that simple.

He prayed to the school to circuit (schematic)!

thanks

Tekko · 9th July 2011, 07:27 PM

its simple, a resistor from C to B about 1k and a 1k pot in series with a 220-500 ohm resistor between B and E. and a cap between C and E.

Adjust pot for around 50-75mA per output pair.

radio · 9th July 2011, 07:59 PM

Quote:

Originally Posted by Tekko

its simple, a resistor from C to B about 1k and a 1k pot in series with a 220-500 ohm resistor between B and E. and a cap between C and E.

Adjust pot for around 50-75mA per output pair.

Thanks and cheers !!

radio · 10th July 2011, 01:43 PM

Quote:

Originally Posted by Tekko

its simple, a resistor from C to B about 1k and a 1k pot in series with a 220-500 ohm resistor between B and E. and a cap between C and E.

Adjust pot for around 50-75mA per output pair.

Here's eating shematic (Figure 1) and thus it must be connected transistor BD139!

thanks

Tekko · 10th July 2011, 02:15 PM

Yeh thats it, just needs atleast 5 pairs of outputs and around 55-75V rails for 500 watts in 4 ohms.

radio · 09:09 AM

OK! Tekko

Hello all!
I need a PCB for this circuit? (500W class-AB audio amplifier!!!)
thanks

9th July 2011, 01:44 PM	#3
Tekko diyAudio Member Join Date: Jan 2005	Just replace the diodes with a VBE multipler, its really that simple. __________________ The point of life is to build atleast one audio amplifier before you die.

9th July 2011, 07:27 PM	#6
Tekko diyAudio Member Join Date: Jan 2005	its simple, a resistor from C to B about 1k and a 1k pot in series with a 220-500 ohm resistor between B and E. and a cap between C and E. Adjust pot for around 50-75mA per output pair. __________________ The point of life is to build atleast one audio amplifier before you die.

10th July 2011, 02:15 PM	#9
Tekko diyAudio Member Join Date: Jan 2005	Yeh thats it, just needs atleast 5 pairs of outputs and around 55-75V rails for 500 watts in 4 ohms. __________________ The point of life is to build atleast one audio amplifier before you die.

12th July 2011, 09:06 AM	#10
radio diyAudio Member Join Date: Oct 2009 Location: Bitola MACEDONIA	OK! Tekko Hello all! I need a PCB for this circuit? (500W class-AB audio amplifier!!!) thanks Last edited by radio; 12th July 2011 at 09:09 AM.

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