I have found a circuit that i am building but just have a question if it is possible too feed the circuit 30 or 40 or 50 volts? I mean the dc output after the filter circuit.

 

LM317N is rated to 40V max input.
You want to use LM317HV which is rated to 60V max.
Also 2N3055 is rated to 60V max.

 

You want to feed it with the minimum voltage needed for the output, about 3V above the output. Any higher voltage results in a lot of heat. In fact, at 8A each extra volt caused 8W of power lost to heat.

Bob

 

i did once a relatively high voltage input supply test prj.
the reason was that the power demand quickly drew the input down to it's half - compared to unloaded
so i used 3 stages

1. minimal input filter coz i didn't had the required large and high voltage capacitors
   consisting of NPN capacitor multiplier , rectifier diode , smoothing inductor , more cap.-s)
2. intermediate linear voltage regulator - a special optimized design for the last stage never to see ??? more than about 14.7V
3. final linear reg.

it worked fine , but since i could not fit it to the available case - it was not used afterwards

just use any buck design that supports your I/O voltage ranges and power demand and your done - if not - drop your voltage by SMPS then smooth it by LDO (or with what you already have at #1 . . . 0 to 28 V -- maybe what i just said is not a good suggestion in this case
Option 2. is to make a "tracking" buck that keeps some headroom for the last stage

 

LM317N is rated to 40V max input.
You want to use LM317HV which is rated to 60V max.
Also 2N3055 is rated to 60V max.

Thank you i will try it!