My understanding is that the build quality of the YBA amp is superb. I don’t have the manual and have not been able to locate one, but it appears it’s spec’d at 120 wpc into 8 ohms, although I have been told that’s very conservative. It apparently sold at $6500 new (I paid $1250). It’s not a question of not enough bass, I find the Harbeth’s to be extremely well-balanced and I have never experienced listener fatigue. It’s just that I wonder sometimes whether more power would be better. Budget-wise, I’d like to spend less than $5000 (as much less as possible). I have always been intrigued by reviews and discussions within this forum where Harbeth’s are being driven by 30 wpc Pass Class A amps. The whole wpc thing is still a mystery to me. What power amps have Harbeth 30.2 owners found to work best?