In my loudspeaker system Bavarian Voice 88 the power supply for the field coil is a very important part (see also: a great power supply).
My SupraVox Woofer seems to be very sensitive on the power supply.
Having used standard industrial PS designs I was never really happy. My friend in Paris came with a logical idea, building a somehow vintage layout which I used in the last five years all the time.
Now, one part, the switch On/Off button, failed to work anymore. It just gave up loosing the lever. I had to replace the simple inner part carrying the lever. We did it with a “German Part”. Ok, nothing is serious about “that nationality”, just mentioning it. Maybe it will last now six years ore more…
When I put it into my car and made a snapshot for my friend I was puzzled by the difference between this kind of a “vintage part” and the future characteristic of the car.