Hey there I am working on a project for guitar amplifier. So project requires 25-0-25 step down transformer. What is this. I mean how will it output voltage. Would 25+ and -25, +25 and 0 or something that will result total pd of 25. Well i will be testing my circuit in software simulation so i required help for it. I am beginner in electronic (Science student of A-levels).

Here is the description of project regarding transformers. I am bit confuse about output 25-0-25 transformer but +/-35 output.?

The amplifier is designed for a maximum loaded supply voltage of +/-35V, and this must not be exceeded. Normal tolerance for mains variations is +/-10%, and this is allowed for. The transformer must be rated for a nominal 25-0-25 volt output, and no more.
25-0-25 means it puts out +25v AC when measure from the 0, which is a center-tap.
Here's the three wires coming from the secondary:

Last edited by Invader Jim at Jul 19, 2008,
+25AC? The voltage across one end and the 0v tap will be 25VAC. Across the two outer ends, it will be 50VAC.
But standards don't utilize polarity when referencing AC voltages. Simply 25VAC will suffice.