I myself asked the same question on this forum. Here is the thread.

http://forum.allaboutcircuits.com/showthread.php?t=25404

Everyone says you can only use it if its a class A amp..

Moreover, what are you going to do with the 12v 20A output from the SMPS instead of 70V 1.5A???

 

I thought I can connect some 5V, 3V, and 12V sources to get 70v
Maybe I can connect two or three power supplies... This is giving me a headache.... HELP

Rgds,
Nenad

 

People here have given you a lot of good pointers. So what is the problem? Do live on a place where parts are hard to get, or is this some hobby/school project that you do not want/ or cant not to spend much money on. Please tell us, so we can help better.

 

Hello,

If you want to keep it simple, use a 2 X 25 Volts transformer, rectify and buffer.
You will endup with 70 Volts.
Attached a datasheet of 120 VA transformers.

Greetings,
Bertus

 

If you want to keep it simple, use a 2 X 25 Volts transformer, rectify and buffer.
You will endup with 70 Volts.
Attached a datasheet of 120 VA transformers.

I suggested that to the OP. Also that if he is on a budget to use a 25-0-25 3A. Not responded.

 

Thank you guys...

Regaerds,
Nenad