Hi Daniele,
It would seem so, yes … but I cannot really speculate.
I was checking a little on google, I found this model to be from around 1985. The backplates were much different back then – really everything was different and still in development stages. The regulated bias voltage in back plates now are variable and I have been told many times and I continuously forget. But the old models the voltage potential was much lower because materials and insulation could not survive higher voltages. I know the panels now at peak music power will generate up to 30,000 volts. The older maximum was more like 10,000 I think. Keep in mind the backplates now only draw 2 watts to charge the panel… but I am not at all qualified to comment more and I am afraid I am not sure how I might help you, but someone else on this forum might help.