I have some spare time during this Christmas and New Year. Before I continue, I think I should say Happy New Year 2015 to all of you. All the best for us in the upcoming year. More fun stuff to try, better music, better system, and better revenue also ;-). Well, this is an expensive hobby anyway. I have got this transformer from J&K Audio Design for quite some time. But have not really got chance to try power them up. I guess it’s the right time? The easiest part is to test the filament winding. I put my Sanwa PC510 DMM to measure the unloaded voltage. It was read at 5.63 Volt AC. Hmm… a bit on the high side?


Then I connect my old 5U4C rectifier (5 Volt around 2-3 A load). The voltage measured down to around 5.46 Volt AC. Still a bit on the high side? I know that I ordered 5 A spec, but it should not be that much different.


Then I suspect the mains voltage. Voila, I could read 240 VAC on my mains. Am I in Jakarta or in Penang? 😉 It could be that during this holiday season, the load is low due to many people are in vacation. I should expect the mains will be around 220 VAC as that’s the normal voltage in my area (well, at least few years ago when I checked).


Here is the close inspection of the tube rectifier used, Russian OTK 5U4C. It’s cheap and well performing rectifier tube.