Can Music Reference MR9 drive Tannoy DMT 215 II

Roger Modjeski measured my old RM-9 on his bench and we could easily see it was putting out close to 125 watts per side. That should be more than enough for what appears to be very efficient speakers.

I would be surprised if the RM-9 were the source of the noise but as previously mentioned the sensitivity of your speakers will let more noise through. An easy test is to get a set of shorting plugs and put them on the inputs of the amp. Then turn it on and listen for any noise at the speaker. If no noise or the noise you currently hear is reduced then the problem is elsewhere. Another thing, if you are using unshielded cables on the amp due to where the inputs st so close to the transformers they may be picking up some noise. Roger recommends shielded cables and a bit extra length that allows you to move the cables away from the transformers.

Roger's amps are designed take advantage of light loading. Using the 4 ohm tap on an 8 ohm speaker will decrease power output (20%) or so, but lower distortion and provide additional benefits. I believe in addition to a 4 ohm tap the RM-9 has a 2 ohm tap. So try them all.

Okay to achieve 2 ohms on the RM-9 all you have to do is hook up the positive lead on the 8 ohm tap and the negative lead on the 4 ohm tap. Do this for each channel. Then connect the corresponding ends to your speaker binding posts. I have done this with my RM-10 so it should work on your amp too. If you go over to the Music Reference frum on Audio Circle you will find more information on light loading.