After a long time waiting, finally I got this transformer on hand – myself. This is the Ultimate Level 4 Power Transformer from J&K Audio Design. You can read some detail here and here.

My first impression was: Heavy! Each of this power transformer has around 4-4.5 Kg of weight (need to find my scale to measure it right).

My second impression was the build quality. It has sturdy cover and excellent easy to solder turret. The transformer cover reminds me of old Tamura transformer (not exactly the same, but a bit similar).


The turret on High Voltage power transformer. I ordered 320 and 240 VAC option for High Voltage purpose. A bit high for pre-amplifier usage, but be noted that I’m using Choke Input most of the time on my application.


Below is the Low Voltage or Filament transformer. Nothing really special, only standar 6.3 VAC windings and 0-4-5 VAC rectifier winding to cover most common 5V rectifier and classic 4V RGN/AZ rectifier.


The benefit of having two separate High Voltage and Low Voltage transformer is you can always switch them on separately (Low Voltage should come first). Once the tubes are pre-heated enough around 60-90 seconds, then the High Voltage could be switched on (manual or automatic with delay relay). Many people don’t believe this kind of old trick, but for the sake of longevity of our old tubes, then this is nothing.

Be noted that the mains wiring should be arranged properly in order to make sure the High Voltage power transformer can’t be switched on if the Low Voltage/Filament power transformer is not switched on yet.