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The main difference between a U1 and a U3 is just that the U3 is just slightly bigger. This gives it 2 main advantages. First, the extra height means that it can house longer strings which result in a warmer, richer sound. Second, it has a larger soundboard which is also good for producing a richer, more resonant tone. Other than that, they are equal. The action is just as good, the build quality and component quality is just as good. It’s just that the tone quality is a notch better on the U3. The U1 is not a small piano so it does still have a good, rich tone, just not quite as rich as the U3. So if your budget will stretch I recommend the Yamaha U3. Otherwise, the U1 will satisfy the needs of most pianists perfectly well for the rest of their musical life.
Some of my U3 pianos are bright, some are medium and some are mellow. This is mainly down to the soundboards being unique from one piano to the next. The job of the soundboard is to amplify the vibrations from the strings and so each different soundboard gives each piano it’s own unique “voice”. However, when it comes to the Yamaha U1 pianos, they seem to have a much more consistent tone, there is less variation between bright and mellow. I’m not certain why that is but it does tend to be the case. It is therefore quite easy to choose a Yamaha U1 because they all sound so similar. Choosing a U3, however, is therefore a bit trickier because you have to figure out if you like a mellow, bright or medium tone. It’s good to have the choice of course because for a room with a hard floor and no soft furnishings you should look to choose a mellow piano. For a room with a heavy carpet and curtains etc a brighter piano would be a better choice. So it’s good that the U3s give you that choice of tone.
The Yamaha U3 is much more popular than the U1 and so I try to keep more U3s in stock than U1s to give my U3 shoppers a bigger choice. I probably sell five U3s to every U1 and the reason for this seems to be that once a person has decided that they are spending this much money, they don’t mind stretching that bit further to get the best sound quality possible. There is a £500 difference between a U1 and U3 of identical age and condition.
Here are the Yamaha U1 and U3 dimensions.
Yamaha U1 Dimensions
Height: 48in / 121cm
Width: 60in / 151cm
Depth: 24in / 61.5cm
From floor to keyboard: 24in and 1/16th / 61.2cm
Yamaha U3 Dimension
Height: 52in / 130.5cm
Width: 60.5in / 153.5cm
Depth: 25.5in / 65cm
From floor to keyboard: 24.5in / 62.2cm
If you are worried about whether a Yamaha U1 or U3 will fit into your house, please create a cardboard cutout using the above diagrams. If you can slide the cutout along the floor and around the tight corners without touching the walls then the piano will fit. Try the cutout in various orientations if it doesn’t fit at first. Flip it over and try going in top first and then bottom first to see what works best.
I hope this info helps