McIntosh MC 275 Mk IV or V with Harbeth M-40.1?


I've had my Plinius SA-102 for longer than any previous amp (almost 3 years) and have been very satisfied with it's reliability, musicality and build quality, but I'm very intrigued with finally trying a classic tube amp.

I listen to classical, jazz, vocals & acoustic rock at moderate volume levels, so I'm thinking the 75 WPC of the McIntosh MC 275 (mk IV or V) would work fine in my 15' x 21' x 7' basement set up. The Harbeth M-40.1's sensitivity is 85dB/W/m, 6 ohm nominal. Suggested amplification: >50W (Stereophile's review of the M-40.1's noted excellent success when driven by a 35wpc Shindo push-pull amp)

I've researched other tube amps from Rogue (M120's & 150's), VTL (ST-150), Manley (Snappers), Cary (120S), Audio Research (VT-100 MK III) and Quicksilver (V-4's). Ultimately I'm leaning heavily towards the Mac MC 275 (Mk IV or V) due to its not being a monoblock, it's a classic unit with excellent build quality and good resale value, and it's known to be reliable and is easy to bias.

Preamp is an Aesthetix Calypso with NOS tubes and my sources are digital and FM.

Comments from those experienced with later model McIntosh MC 275 and/or Harbeth M-40.1's would be appreciated.

Thanks - Paul

128x128pdreher
Tom - so far, so good. I'm currently listening with all of the stock tubes to get a feel for things, but have the NOS RCA 5751's & Sylvania 12AT7's ready to roll. Surprisingly, the amp sounds really, really good with just the stock tubes... a very pleasant surprise ;o).

The MC275 with the stock tubes is lacking the detail & refinement provided by my previous amp (Plinius SA-102), but it's noticeably more musical, natural and robust sounding without being in your face... I'm really loving it! Will be interesting to see if the NOS signal tubes take the sound to a new level.
Hope it gets even better for you. Does the drop off in power seem to be an issue with the new amp?
The drop in power suits the M-40.1's just fine. I do have to turn up my preamp about 5 more db's to get the same volume, but the speakers are not lacking any grunt. If anything, the sound is more full & robust moving from ss to tubes, at least in my particular situation.
My father had the original 275 for 40 years with never a sick day. I concur with the 40.1s--incredible speakers that will play to the amps strengths. I can also recommend ATC 19s and Spendor A6s.
IMO, I would think the Mac with the 40.1s would be too much of a "good thang".Never heard them together ,only in seperate system and wouldnt own either..guess thats what makes this an interesting hobby..