Talked to Roland Customer Support twice.
First time I got the answer "I'm not really sure, but I think it is a switching power supply".
Second time the Person didn't even know about "VA-76". I had to repeat the model name "va-76" to him about 6 times, but he couldn't even find VA-76 model in their database or wherever he was searching for it.

So I'm still searching for the answer.

if Next time I'll be calling Roland US, I'll try to record the conversation.