I have a Yamaha preamplifier CX-800/U where the Powertransformer is defect which let the primary 220V transform into secondary voltages.I know the transformer is no longer available but i would like to change it with a universal transformer.I would only like to know which voltages exactly are secondary(2 orange wires and 2 red&1black wire)I've searched for the service manual with the electric diagrams but till now i've not be able to find it.I would be gratefull if You could help me with this matter.Thank You in advance!

I asked for more info, but I have replaced many hundreds of unobtainable transformers. All the voltages can be found by a bit of logic thinking & observation. If I have the item in front of me I will have the solution in minutes.
Double red with black, expecially together is normally a X-0-X winding, identified by the rectifier & smoothing caps. The voltages on them will give some indication, but tracing the voltage to an regulator is an accurate solution.
What are the voltages used for?
Normally the one winding will be a low voltage like 12-18 volt for the pre-amps mixers etc. This very often will go through oner or more voltage regulators. Their voltage is written on them,and they will have have small heatsink on them & live near the rectifiers & caps. Look for three legged items marked something like 7812. This is a 12 volt reghulater while a 7809 is a 9 volt regulater. The split voltage say from 20-0-20 to 80-0-80 max will drive the power amp. A 20 watt stereo amp will most likely use two integrated circuits. Luckily you can find their operating voltages very easily by typing in their number like TDS2005 into google. As for an output stage like a 60 to 100 Watt amplifier, a voltage like 60 0 60 and 80 0 80 is used. If in doubt, go a bit lower & play safe. All you will loose is a few watts. If logic (computer circuitry) is used, all computers use basic only 12 volt and 5 volt. Very easy.
Before you give up or look for a new transformeer, just check!!!!!
Most *** xformers have a secret fuse inside them which is easily replaced if you know how!
Send photos! (under 60Kb)