A regenerator circuit does not have infinite power. It is common for them to not be very happy with tube amps of higher power. This seems to be because they don't like heavy loads that have a lot of constant current, and your ARC has a substantial filament circuit.
FWIW there is a company called Elgar that made the world's best power conditioners **bar none**. They don't make them anymore, so you would have to look for one used and have it rebuilt. But the big one could run 28Amps of current continuously and put out a perfect sine wave. I think they made a smaller one that was rated at 15Amps as well.
They are mechanically noisy so what people usually do is install them by the home's breaker box, and run the line for the audio room off of the conditioner.
FWIW there is a company called Elgar that made the world's best power conditioners **bar none**. They don't make them anymore, so you would have to look for one used and have it rebuilt. But the big one could run 28Amps of current continuously and put out a perfect sine wave. I think they made a smaller one that was rated at 15Amps as well.
They are mechanically noisy so what people usually do is install them by the home's breaker box, and run the line for the audio room off of the conditioner.