AFAIK, in EU N is grounded all the way back in the utility junction cabin, or wherever the first star-wired triphase transformer happens to be, and not at the end user. For better or worse. The end user should have a gnd pole at their end use point. I never understood why they do that but I believe that's the cause of the large spikes on EU power lines. The kinds that blow your stuff up during thunderstorms.
Large spikes blowing up stuff, thunderstorms?! Some countries want their data centers in the EU because of the reliability of the grid.
Anyway the system is to protect civilians by design and not by designing stuff to kill. It is a philosophy.
Anyway the system is to protect civilians by design and not by designing stuff to kill. It is a philosophy.
Datacenters in EU? and pay 10x the utility costs? That sounds like fake news. 😉 Yes, power reliability is great in EU, compared to what we get here. I don't remember ever experiencing a blackout in 30y.
However, more or less everyone in Spain, Italy and France either experienced it personally or know someone whose TV or other appliance blew up during a thunderstorm in the 70s to the 90s. Probably they fixed it now with more modern surge suppression systems.
However, more or less everyone in Spain, Italy and France either experienced it personally or know someone whose TV or other appliance blew up during a thunderstorm in the 70s to the 90s. Probably they fixed it now with more modern surge suppression systems.
Is that the Japanese export version? It has at least 6 wires at the primary side which is a very good sign.
That is the US/EU version, which will have the part # I am looking for, but unfortunately not legible from the photos. I had a good search but could not find anything. I wonder if it is the same part as my SIT2 (AnTek AN3232, 2x32V out). I really would need a SIT1 owner to look for me and comment. The Japanese version will tell me the voltage of the secondaries but not the VA used in the US/EU amp, so I can’t be 100% sure about the AnTek part #.
So, it’s a 115v -> 45V AnTek AN3245.
In Japan at 100V this would output 39.1V
If I rewire the jumper and run at 230V it will output 45V.
Now… what to do? Replace transformer with one that outputs 39V? Run with this transformer with windings in series so that it outputs 45V?
I guess the only way to know is to understand the part number of the US/EU SIT1?
In Japan at 100V this would output 39.1V
If I rewire the jumper and run at 230V it will output 45V.
Now… what to do? Replace transformer with one that outputs 39V? Run with this transformer with windings in series so that it outputs 45V?
I guess the only way to know is to understand the part number of the US/EU SIT1?
This transformer can be connected to 230V. So in a way you are lucky as they can be reused/sold. It could be the Japanese version was designed to be used with under voltage. 100V mains to parallel 115V windings. Never a saturating transformer 🙂 More likely the manufacturer needed the specific output voltage of 2 x 40V but had to deal with unusual 100V mains voltage and solved it like this by choosing a type with upped output voltages to compensate for undervolting the 115V primaries. Nothing wrong with that. Most standard transformers are wound for 2 x 115V for global use with Japan being an exception.
Yes you need to know output voltage of the EU sold version for 100% certainty. Better safe than sorry.
Yes you need to know output voltage of the EU sold version for 100% certainty. Better safe than sorry.
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I wonder then if this amp was biased to run at an operating point optimized @39V? A part of the bias is adjustable though via the dial, so maybe the what would be the mid-point on that dial in Japan would be slightly offset when running @45V?
it is wired as two primaries in parallel, secondaries are in series..... and you don't even need to think about secondaries .............. 90Vac is proper arrangement, btw.
now, take proper close pic of PSU pcb where primary voltage bridges are, to see what needs to be changed for wiring primaries in series, and you'll have 230 primaries
now, take proper close pic of PSU pcb where primary voltage bridges are, to see what needs to be changed for wiring primaries in series, and you'll have 230 primaries
So just to be 100% sure, I remove the 2 x CL60s across the 120, and place a single one across the 240?
exactly
then dial front bias button all CCW, power it up
see can you set bias to mid position of needle meter and is it around mid position of dial button
eventually you'll need to re-set one trimpot inside to fine tune that
details later, if needed
It can be a wise idea to not solder the transformers wires straight to the PCB but to use screw connectors by Phoenix. That way the boards don’t suffer and you can replace/rewire more easily in case the transformers do need to be replaced. The electrolytic caps are 100V rated.