Powervalue too low from P5

When I connect my preamp to the P5 it shows low power compared to the stated effect.It shows 25W, where the rated power is 50W.I have then connected it to the wall instead and here the sound Is more powerfull.My question is are some appliances not suitable for regeneration?

Regards

Bjorn

The P5 is giving you accurate information, the preamp user manual is apparently not. The P5 is more than adequate to handle the preamp and should help it sound far better. I am not sure what you mean by more powerful. On my systems when I plug a preamp in the increase in harmonic detail, greater information and space is quite noticeable instantly. I would be surprised if yours didn’t do the same - but do be careful with power cords.