QUASI Amplifier for Beginners

[apexaudio]

Hello Apex sir

b550 amp circuit with op 2sc5200, +-35v is enuff for one pair of 5200.Help if any other changes required in circuit.And which PCB layout is correct, please mention,

Use PCB from post #294

 

[behrad]

mr mile
can i use 2n3055 instead 2n3773?
my traFFO IS +/-50V DC

 

[Vrystaat]

Apex vu circuit

Hallo all,
I need some help please.
Ground goes to 0V of power supply.
HV+ goes to + rail of power supply.
Left /Right goes to speaker output of amplifier.
My supply rails are +-40VDC. Is there any changes that needs to be done ?

 

[behrad]

Hallo all,
I need some help please.
Ground goes to 0V of power supply.
HV+ goes to + rail of power supply.
Left /Right goes to speaker output of amplifier.
My supply rails are +-40VDC. Is there any changes that needs to be done ?

No need to chahge
Apex vu meter work with +/_40v power supply

 

[Vrystaat]

Behrad, thanks for that. I see the original circuit uses MPSA42/92 transistors which are 300V vce transistors. Are they necessary when using 0-40VDC supply or can lower voltage transistors be used ?

 

[behrad]

Behrad, thanks for that. I see the original circuit uses MPSA42/92 transistors which are 300V vce transistors. Are they necessary when using 0-40VDC supply or can lower voltage transistors be used ?

U dont need to tra with lower vce voltage
Mpsa42/92 is ok for +/-40v power
Respectfully

 

[thimios]

Hallo all,
I need some help please.
Ground goes to 0V of power supply.
HV+ goes to + rail of power supply.
Left /Right goes to speaker output of amplifier.
My supply rails are +-40VDC. Is there any changes that needs to be done ?

Please Jan, post this in black&white for home etching.

 

[Vrystaat]

There you are !!

 

[Vrystaat]

Apex do you perhaps have the flip side of the pcb layout. Will it be possible to use lower voltage transistors in the place of the MPSA42/92 on 40vdc rails ?

 

[djk]

"can i use 2n3055 instead 2n3773?"

If your supply voltage is ±30 VDC or less, yes.

 

[john_ellis]

"can i use 2n3055 instead 2n3773?"
Or if you use Rbe<=100 ohms 2N3055 is OK to +/-35V.

 

[Aaron Nikhil]

I plan to modify my 10 stereo amplifiers which are made as per cosmic amplifier Circuits with 4pairs 2n3055 each channel. I personally rely much on metal casing transistors. with lots of regard vedmitra Sharma from city of Tajmahal.

Dear Vedmitra Sharma,
Cosmic amplifier Circuits are based on Cosmic LAB Stereomaster Series or Pro Power MK-II Swrites?
I hope you implied "Cosmic" based in Mumbai.

Regards
Aaron Nikhil
from a City of Charminar.

 

[fuego]

PCB with DC protection.

what size have the PCB ?
is tested by someone?

 

[desislavov]

i made quasi , sound is OK i can`t hear distortions
but 22K resistor is going too hot .
I move it to GND and now is perfect ....

apexaudio is that OK ?

 

[prasi]

Hello Mr. Mile,
Can this amp be made more stable and reliable to give about 200W-4ohm. Also with to-247/264 transistors.

regards
prasi

 

[prasi]

Hello Mr. Mile,
Can this amp be made more stable and reliable to give about 200W-4ohm. Also with to-247/264 transistors.

regards
prasi

Here is slightly better version of pcb.

 

[jose lasso]

Very good

 

[jose lasso]

An externally hosted image should be here but it was not working when we last tested it.

 

[vcledel]

Greetings to all .. what changes would have to be made to this amplifier to be able to use mosfet in its output? How would the schematic look?

 

[Joel Wesseling]

Here is slightly better version of pcb.

Are the Gerbers available. Thanks!