I have a creative speakers model no MF1580 and it has 230v to 8v 250 mA transformer and I tested the transformer ,its not working so I'm not getting same rated transformer can I use 9v 250mA instead.
My guess is that it will work just fine. A lot of those transformers do not have a very precise voltage output because it depends on the current drawn from it. In most cases, the appliance designer allows a variation in input voltage anyway, and just a little bit more voltage shouldn't harm anything. It's likely able to withstand 50% or even 100% more than that to allow for occasional voltage spikes from the power lines. You will be fine!