500W PA amplifier with Limiter

[engel dela pena]

anybody
please give me mic,line pre amp link
thanks

 

[apexaudio]

anybody
please give me mic,line pre amp link
thanks

Link for this?
http://www.diyaudio.com/forums/solid-state/167363-mic-line-eq-preamps.html
Regards

 

[apexaudio]

I suggest to try B500 with HI-Fi speakers...

 

[mihailo]

B500

Hi,Apex.
I had discovered why my B500 little buzz on speakers when there is no music. My computer is generating that sound. When I disconnect cinc, it stops. 🙂
Can amplifier work with 2SB817/2SD1047, BD249/BD250 transistors without changing anything, with lower voltage? I have some supplies of those transistors. 😀

 

[apexaudio]

Hi,Apex.
I had discovered why my B500 little buzz on speakers when there is no music. My computer is generating that sound. When I disconnect cinc, it stops. 🙂
Can amplifier work with 2SB817/2SD1047, BD249/BD250 transistors without changing anything, with lower voltage? I have some supplies of those transistors. 😀

See post #40, and in thread http://www.diyaudio.com/forums/solid-state/164630-50w-mosfet-amplifier-irf540-irf9540-3.html you can also see post #23. Can you post some pictures? What speakers you use, and how its sound with B500 compareing with another amps?
Regards

 

[mihailo]

B500 is stronger then most amplifiers I had build before.
Great sound on hifi speakers, used Pioneer and EI Nis for Hi-fi test.
And Eminence Kappa 18" and Delta 12" LF for PA test.
Will post pictures in a few days.
I had look you posts, this amplifier is just like B500 but with 2SB817/2SD1047 transistors and 2K2/5W resistors. Are there any change in pcb?

 

[apexaudio]

B500 is stronger then most amplifiers I had build before.
Great sound on hifi speakers, used Pioneer and EI Nis for Hi-fi test.
And Eminence Kappa 18" and Delta 12" LF for PA test.
Will post pictures in a few days.
I had look you posts, this amplifier is just like B500 but with 2SB817/2SD1047 transistors and 2K2/5W resistors. Are there any change in pcb?

You can use B500 pcb for B250,
Regards

 

[mihailo]

Thanks Apex! 🙂
Regards

 

[apexaudio]

NSL32 can be replaced with 47k resistor and LED for 'clip' indicate, if you don't want use limiter,
Regards

 

[Rafael S. M.]

I wonder what advantage they gain by using that scheme of dual voltage supply with switching FET, greater power? greater efficiency?

This circuit can be adapted to any amp? (Of course, changing something and another)

Finally, it is the class H?

 

[smartx21]

Improper shielding

I had discovered why my B500 little buzz on speakers when there is no music. My computer is generating that sound. When I disconnect cinc, it stops.

Check your cable quality also. Even when I suspected that my computer was the faulty piece, in fact, the cable I used to do the connection had improper shielding!
Regards,
Max.

 

[mihailo]

Hi, Apex.
Pictures of my B500. 😀

 

[mihailo]

And pcb of Apex 120 with BDE83/84.
One of my technics of making PCB: 🙂
1.print PCB on paper
2.Use iron to transfer print(lines) on PCB
3.put pcb with paper in cold water

 

[mihailo]

More pictures...

 

[ReiMomo]

Why the iron transfer method never work for me?

 

[mihailo]

I don't know.
1.Use laser printer. Select dark option when you print.
2.best paper is for pictures, but i use average business paper 80gr./A4 and it work fine for me.
3.Iron must be very hot,you mush press for 7-8 min. and more...
4.Then put PCb in cold water
Watch on youtube:
YouTube - Making PCBs using Toner Transfer

 

[mihailo]

YouTube - Making a PCB at home with the toner transfer method.

 

[apexaudio]

Hi, Apex.
Pictures of my B500. 😀

Nice work, and what is your PSU specification?
Regards

 

[mihailo]

Thanks, Apex.
For test I used transformer with +/-60V 300w.
Even with +/-60V amplifier is very powerfull.

 

[mihailo]

Rack is waiting for second channel and toroid transformer. Will post pictures soon,when finish whole amplifier.
My PA200 is visually very similar with yours B500, but weaker. 😱