Your amp circuit has to be designed with this in mind. It is highly recomended you never go over half of that rating, which will generally be satisfied with plate power supplies up to some 350V (perhaps more on autobias designs).ģ) Toroids are FAR less imune to core saturation due to unbalanced DC flux in the core, in fact out of all transformer types they are the worst in this respect. This is important since you will get best results usung mains transformers with a dual bifilary would 115V mains primary. Custom winding the transformer for the proper voltage and a low frequency (most winders can calculate all they need based on that) will give you much better results.Ģ) Take care of the voltage rating, the standard wire enamel used can withstand about 600V between adjecent windings. One of the reasons is that you will normally be using dual 115V mains primaries as the PP primary, which will usually see a much higher voltage - this means you have a 'shortage of turns'. Toroidal (ring core) transformers can actually give you surprisingly good results provided they are specified and used properly:ġ) they will have a MUCH smaller power raing for audio frequencies (particulairly the low end) than the mains use rating, often 10 times lower. So i am dc decopled from the amplifier so these transformers sound pretty niceĭoes anybody know something about the dc currents in primairy coils of transformers but keep in mind if current is passing trough 100v speaker transformers will the full output power be achieved These put out a nice 5 watts and in the circuit is an output capacitor I am building an power amplifier with 2 el86 in srpp

Now for the transformer in push pull schematic the dc current is flowing in both directions in the primairy coils, don't the magnetic forces in the core cancel each other out.Īnd if so it is theoreticly possible to use a 2000 ohm centre taped 100v speaker transformer that was obviously not designed for dc currents. These air gap transformers don't get saturated in there core when dc is passing trough. I was just wondering, i know that by single ended amplifiers the output transformer is of an kind that can handle dc currents

Push pull output transformer design