500W PA amplifier with Limiter

[apexaudio]

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

This picture is better post in thread:
http://www.diyaudio.com/forums/solid-state/164093-100w-ultimate-fidelity-amplifier-19.html
Regards

 

[apexaudio]

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.

It's not similar, you have global feedback from amp output to OP amp input. B500 use OP amp as AC buffer and DC servo.
Regards

 

[mihailo]

Sorry, if I insult you in some way. Your amp is different and better in every way.
I meant visually by dimensions, part places and parts I use... not by how it works.
As you said to me ''My PA200 is very similar like old project PA300 with MJE15003".
But thanks for explaining to me how P200 works.
Regards

 

[apexaudio]

Sorry, if I insult you in some way. Your amp is different and better in every way.
I meant visually by dimensions, part places and parts I use... not by how it works.
As you said to me ''My PA200 is very similar like old project PA300 with MJE15003".
But thanks for explaining to me how P200 works.
Regards

I share B500 with all forum members, now that is our amp. Thank you for build B500 and post pictures. I expect more amps in future use this topology.
Regards

 

[electra_ina]

Apex..this my picture B500 after add fan, so 2 fan (sorry can't see that picture) and adding capasitor 0,22 uf/630v (yellow) + Resistor 17K/2w paralel with capasitor bank in PSU and softstart in AC in. With adding this, how effect for B500?
Pozdrav,

 

[apexaudio]

Apex..this my picture B500 after add fan, so 2 fan (sorry can't see that picture) and adding capasitor 0,22 uf/630v (yellow) + Resistor 17K/2w paralel with capasitor bank in PSU and softstart in AC in. With adding this, how effect for B500?
Pozdrav,

I expect many upgrades in a future, and you share your expiriance with us. This upgrades you did is OK. Thank you for building and post pictures.
Pozdrav

 

[mihailo]

Apex, can I use voltage from main transformator, for protection or I must buy another?

 

[apexaudio]

Apex, can I use voltage from main transformator, for protection or I must buy another?

Yes if you have 2x18Vac 500mA secundar on your main transformer,
Regards

 

[mihailo]

I meant to decrease voltage +/-80V with resistors,zener diode and power transistors.

 

[mihailo]

Something like this.

 

[apexaudio]

I meant to decrease voltage +/-80V with resistors,zener diode and power transistors.

This is posible, but you have high disipation and must use large heatsinks for transistor, and if you have demage of transistor, there will be +/-80V on protect and this cause lot of demage. Simple and not expensive solution is to use extra 2x18v smal transformer,
Regards

 

[mihailo]

Thanks Apex. I will do like you said.
regards

 

[electra_ina]

I expect many upgrades in a future, and you share your expiriance with us. This upgrades you did is OK. Thank you for building and post pictures.
Pozdrav

Thanks welcome..
I build it (and H900) just for hobby and I will share my pictures "Apex Project" . It's will be used on little party (like wedding) on my place...Thanks Apex.
Pozdrav.

 

[electra_ina]

applied NSL-32

Hi Apex,
confirm: how to applied NSL-32 on PCB B500? NSL-32 just arrived from my friends in Singapore. In your PCB B500, drawing NSL-32 with "dot" is it match with "dot" on body NSL-32?? This ilustration:

Sorry, stupid question...
Regards

 

[apexaudio]

Hi Apex,
confirm: how to applied NSL-32 on PCB B500? NSL-32 just arrived from my friends in Singapore. In your PCB B500, drawing NSL-32 with "dot" is it match with "dot" on body NSL-32?? This ilustration:



Sorry, stupid question...
Regards

Dot is katode of LED inside NSL32, resistor is on oposite side,
Regards

 

[mihailo]

Hi, Apex.
What do you think about this amplifier?
Have you build something like this?

 

[mihailo]

Schematics.
I resized this picture because it's to big,if you want better resolution I will send you by mail.
regards

 

[AndrewT]

the resolution just abouts makes the drawings legible.

Two hints for future posting.
Crop the drawing right down to the borders of the necessary information.
Use the next size up on font.

 

[mihailo]

Thanks. i will do like you said.
Regards

 

[mihailo]

More pictures...