Hi, The MAC4100 is a 75 watt/ch am/fm stereo receiver with (power guard)which is very hard to drive past 2% distortion and I would say that it is closer to a Marantz 2275 then a model 19 the MAC4100 has a much better AM circuit then the Marantz 2275 and the FM is about the same . The 19 is a special unit in that it has a very good (special) tuner section (same as marantz 20 fm tuner) hence the great fm performence no am on this model, most of todays analog tuners cannot beat it but the 19 is rated at a conservitive 50 watts/ch (no power guard) but has a really cool scope for the display of audio/signal strength/center tuning and multipath. I belive that the MAC4100 is a combination of an Mcintosh MA6200 integrated amp and an MR75 tuner, Hope this helps. Mike