Dave b - Try the decaf.
Adam - I had the larger M-40.1's and drove them with a VAC 30/30 (32 wpc). My guess is you may be fine with with this pairing unless you like to listen to complex music (classic rock, pop, full scale orchestral) at high volume levels. Harbeth's are not made to be cranked at high volumes... they excel @ more moderate volume levels, which is one of the things that makes them appealing. Even though their efficiency rating is not high, they do have a benign impedance curve which makes them a good match with moderately powered tube amps. To be safe, I'd be leaning towards something with a min. of 25 "quality" wpc.
Adam - I had the larger M-40.1's and drove them with a VAC 30/30 (32 wpc). My guess is you may be fine with with this pairing unless you like to listen to complex music (classic rock, pop, full scale orchestral) at high volume levels. Harbeth's are not made to be cranked at high volumes... they excel @ more moderate volume levels, which is one of the things that makes them appealing. Even though their efficiency rating is not high, they do have a benign impedance curve which makes them a good match with moderately powered tube amps. To be safe, I'd be leaning towards something with a min. of 25 "quality" wpc.