Due to shortage of some materials, my custom transformers were delayed a bit. I haven’t got chance to arrange the pickup yet, so I ask Ken to give a quick test of the unloaded voltage. I know the best scenario is to test the transformer on the real world environment with actual fully loaded rail. But you know me, that would be happening sometime later. So just a quick voltage test could be interesting –  for now.

Be noted that this test was done in Malaysia with mains voltage rated at 240 VAC (actual tested at 246 VAC as shown below). So all the secondary voltage also pulled up around 10% higher than the actual specification which was designed for 220 VAC input.

Sorry the pictures are not that good as I have told Ken before, he needs to upgrade his camera!


The first is the first filament, should be rated at 6.3 VAC at 220 VAC, but with 246 VAC input, the value hit the 7.16 VAC.


Second filament which should be rated at the same, also measured the same 7.16 VAC. What a consistent or precision winding.


Next is the 4V winding for my RGN rectifier filament, read at 4.41 VAC.


The 5V windings for RGN rectifier filament. Read at 5.68 VAC.


The high voltage winding. Hmm… looks yummy at 356.8 VAC.


Exactly the same value for the rest half of the winding. Quite precise work!


The lower voltage of the high voltage winding. Read at 267.8 VAC.


I guess you can expect the same VAC for the rest half of the winding. Yes you are correct, the value read exactly the same with the first half of the winding, 267.8 VAC.


Will wait for the transformer to come, test at 220 VAC input, and also loaded with my preamp.