What is a Toroidal Transformer? Also, any info on power supply capacitors? (1 Viewer)

[Kyle_Y]

What is a toroidal transformer, and what benefits does it provide? I notice that one some receivers and amps, they say that they have toroidal transformers, I've seen pictures of them, but what makes them good? I own an Onkyo 797 and my transformer is in a big silver box that was about the size of the one in a Denon 3802, but larger than anything else in it's class. Also about the power supply capacitors, what are they for? My 797 has Nichicon, the same brand as the 989, are those good? Any input would be great, I'm just curious.

 

[Brian Johnston]

Kyle,

I am by no means an expert but from what I was told recently by a saleman about torodial transformers is this:

They are doughnut shaped vs. cubic, this results appearantly in a more condensed electrical field, meaning less contamination/interference with other components in the same unit. This is what I was told in reference to an Arcam AVR200.

Brian.

 

[ling_w]

The funny thing with amps that has torridial transformers is that the orientation inside the amp. Torridial transformers radiate their field above and below the doughnut. So placing one on its side and having the field pointed at some audio board is counter-productive. Laying the doughnut flat so the field goes up and down would probably cause its field to intefere with components above and below the amp, but I guess that is the other equipment's problem. The best would probably have a mu-metal shield around the transformer.

As far as capacitors, they serve two purpose. First, they smooth out the rectified AC signal by acting like a water tank. The DC signal drawn out of the capacitor would be a constant rate, where the 1/2 sinusodal input of the rectified AC signal would get the valley filled and the peaks flattend. The second purpose, since it is like a water tank, it stores alot of reserve energy. When the amp is reproducing a loud signal that is beyond the power delivery of your wall outlet, the reserve comes into play, providing you with enough energy to produce those loud passages. But if the loud passage goes on for too long, the capacitor might run low, resulting in a rippled DC signal being fed to your amp.