I just bought Rullit lab8 Field coil drivers, the best sounding speakers I have heard. they are still breaking in so 100 or 200 more hours to go, but already the low end is impressive, especially in a quasi-open baffle. My power supply now is marginal but I am going to try to build a full wave bridge rectifier with selenium “rectifiers“, which I believe are simply diodes.
I live near Las Vegas and it took a month and a half to get them from Nuremberg Germany. I was getting frustrated but it was worth the wait.
According to Oleg (Rullit) I can use a veriac transformer combined with selenium rectifiers and it should sound great. I would think that a big power capacitor on that and then a DC voltage meter to show what voltage is really coming out would be a good idea.
Glad you are enjoying your Rullit, bought my first pair about 10 years ago still loving them. BTW I have lots of family Members living in Las Vegas.