Thank you. That's the TX30 and mine is the TX15, but I had already read the specifications. The problem is that it doesn't say anything about the amps of the power adapter. It's usually written on the power adapter, so if anyone has the same amp it would be great.
I found two 15V power adapters, one with 3500 mA and another with 5000 mA. The problem is that if the amps are too low, the battery won't charge, and if it's too high it might damage the amplifier.