400Watt PA "SAFARI"

[Riff]

how to increase power from this amp.
Can I get a 500watt of these pa by replacing the final transistor using 2sc5200/2sa1943 x4?

 

[Riff]

 

[moschfet]

how to increase power from this amp.

It is not so easy as it seems.

Can I get a 500watt of these pa by replacing the final transistor using 2sc5200/2sa1943 x4?

No!

 

[Riff]

It is not so easy as it seems.

No!

what are you suggestion?

 

[jaycee]

That circuit is awful. If you want 500W for PA, you really want something rugged with 5x MJ15003/4 or MJ15024/5 with MJE15032/3 driver transistors. It will have to run reliably on 80V supplies.

You can use 2n5551 for inputstage, mje340/350 for vas. You will need a big heatsink, maybe fan cooled. After all that, you may find it was cheaper to buy a readymade PA amp. Maybe if you can get a scrapped one for the case and heatsinks it is worth it.

 

[Riff]

That circuit is awful. If you want 500W for PA, you really want something rugged with 5x MJ15003/4 or MJ15024/5 with MJE15032/3 driver transistors. It will have to run reliably on 80V supplies.

You can use 2n5551 for inputstage, mje340/350 for vas. You will need a big heatsink, maybe fan cooled. After all that, you may find it was cheaper to buy a readymade PA amp. Maybe if you can get a scrapped one for the case and heatsinks it is worth it.

MJ15003/4 or MJ15024/5 is too expensive on my local market...so how if i use 2sc5200/2sa1943 x5?
I've tried the sircuit using 2SC5200/2SA1943 x4 and given the supply 75vdc...for test load 4R 15"+12" device...

 

[Riff]

MJ15003/4 or MJ15024/5

i mean MJ15003/4 or MJ15024/5 is hard to find and even if there is very expensive on my local market,

 

[JOHN BALI]

Hi Riff
This circuit maybe can stand higher voltage if we change some part value...
I'm also curious which one should be changed or how to modified this circuit???
maybe add VBE TR, add TEF etc.

So someone please give suggestion, which component should be changed to
stand up to +/- 70VDC & the power transistor will be 2SC5200/2SA1943.
Please tell us how many output pairs should be use?


Regards

 

[djk]

That amplifier will be about 60W/8Ω on a typical ±40V supply.

Whoever labeled it 400W was demented/on drugs, etc.

 

[moschfet]

That amplifier will be about 60W/8Ω on a typical ±40V supply.

Yes, with an 8 ohm sense resistor. At a speaker, it is probably a bit more:
80-90Watt

But 400Watt I also can not see...

 

[Vostro]

They got to a theoretical Ppk = V*V/R ; (40*40) / 4 = 400W.

But ofcourse this is a lie and can never each this.

With lots of luck 65W rms into 8R.

I'm also scared 3*Vdiode + 47R will bias drivers to hard.

 

[JOHN BALI]

That amplifier will be about 60W/8Ω on a typical ±40V supply.

Whoever labeled it 400W was demented/on drugs, etc.

Hi djk,
Sadly the 400W label really can fool beginner like me few years ago, of course when I'm not an diyAudio member yet. This time quite hard to explain to other people around me "Hey this only labelled 400W, if this kit you powering with 32VAC from trafo you can not have that much power" something like that.
But the one I telling not believe me, they choose to believe the label & the Sanken is 200W device then it is easy to say this circuit can deliver 400W
It is use 4 x 200W device...bla...bla...bla...

They got to a theoretical Ppk = V*V/R ; (40*40) / 4 = 400W.

But ofcourse this is a lie and can never each this.

With lots of luck 65W rms into 8R.

I'm also scared 3*Vdiode + 47R will bias drivers to hard.

Hi Vostro,
I'm also afraid of those 3 diode, many people (here where I live) change the component a bit & powering up to 40VAC &

get some luck the amp just work fine...
The funny thing is I don't know how to do that
This circuit is quite available here where I am, sales as a kit & labelled 400W(1 pair output) or 1200W(2 pair output) how do you think

Ok, then maybe better just use another design.
Tons of good design here @diyAudio waiting to be build

Thanks

 

[naf]

Hi djk,
Sadly the 400W label really can fool beginner like me few years ago, of course when I'm not an diyAudio member yet. This time quite hard to explain to other people around me "Hey this only labelled 400W, if this kit you powering with 32VAC from trafo you can not have that much power" something like that.
But the one I telling not believe me, they choose to believe the label & the Sanken is 200W device then it is easy to say this circuit can deliver 400W
It is use 4 x 200W device...bla...bla...bla...


Hi Vostro,
I'm also afraid of those 3 diode, many people (here where I live) change the component a bit & powering up to 40VAC &

get some luck the amp just work fine...
The funny thing is I don't know how to do that
This circuit is quite available here where I am, sales as a kit & labelled 400W(1 pair output) or 1200W(2 pair output) how do you think

Ok, then maybe better just use another design.
Tons of good design here @diyAudio waiting to be build

Thanks

, right decision John Bali.. tons of good design amp to choose here!
ranging from class A~H...

 

[Riff]

Hi djk,
Sadly the 400W label really can fool beginner like me few years ago, of course when I'm not an diyAudio member yet. This time quite hard to explain to other people around me "Hey this only labelled 400W, if this kit you powering with 32VAC from trafo you can not have that much power" something like that.
But the one I telling not believe me, they choose to believe the label & the Sanken is 200W device then it is easy to say this circuit can deliver 400W
It is use 4 x 200W device...bla...bla...bla...


Hi Vostro,
I'm also afraid of those 3 diode, many people (here where I live) change the component a bit & powering up to 40VAC &

get some luck the amp just work fine...
The funny thing is I don't know how to do that
This circuit is quite available here where I am, sales as a kit & labelled 400W(1 pair output) or 1200W(2 pair output) how do you think

Ok, then maybe better just use another design.
Tons of good design here @diyAudio waiting to be build

Thanks

hi bli jhon...i agree
but the question is whether the above topology really can not produce at least a 400watt?
this is about topology,maybe with part replacement.
how about "tef"... can be applied to the above scheme?

 

[djk]

"this is about topology,maybe with part replacement."

Sure, all that is needed is to change every transistor type number and every other part value, add more outputs, etc. (easy).

I used to change everything on the Pass A40 board and made a 600W class AB amplifier , rather than the 40W class A amplifier the board was designed for.