To me the amplification issue is solved whit this device.
Thanks to Audiophonics that make accessible this great technology at...
Passive power modules.
These supplies rectify (if include diode bridge) and filter the voltage from a transformer to provide a DC voltage.
The calculation of the output voltage is:
Output voltage DC = AC Transformer Voltage x 1.41
Example: A 15V AC transformer, will give a rectified voltage of approximately 21V DC
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