It looks like the Onkyo amp is not powerful enough to drive your friend's Dali's. As a matter of fact, it's rated at 50 watts/ch with a 4 ohm load, so it outputs less than that power to a the Senzor 7, a 6 ohm loudspeaker, something like 30-35 watts which is really insufficient.
What I would recommend is the Yamaha A-S501 integrated amp. This amplifier has a rated power of 85 watts/ch for an 8 ohm load. It would output at least 110 watts/ch to a 6 ohm loudspeaker. That would represent an ideal match for your Dali's. However, I think there's a strong possibility that it's production was discontinued. I would suggest that you verify with Crutchfield as they show it as being out of stock. The A-S701 which is available would be another option. It is slightly more powerful and more expensive. With Crutchfield, you have the possibility of returning it if for any reason, it does not satisfy your needs.
Pure sound quality and outstanding drive power. An integrated amplifier with the advantage of analog and digital inputs.
usa.yamaha.com