Both are Yamaha uprights, yet the 10cm between a 121cm and a 131cm piano โ and the era behind a used model code โ can shape your choice.
The U1 stands 121cm tall and suits smaller rooms; the U3 is about 131cm, with longer strings and a fuller sound. The YUS series is Yamaha's step-up from the U series, and on a used piano the model suffix and serial number reveal its age.
The U series is Yamaha's long-running line of professional uprights; the U3 has been made since the 1950s, and the U1 and U3 are its two core models. According to Tom Lee Music's listing, the U1 is 121cm high, 153cm wide and 62cm deep, and weighs 228kg.
The U3 stands about 131cm, roughly 10cm taller. Mark Goodwin Pianos, a UK dealer in used Yamahas, explains that the extra height accommodates longer strings and a larger soundboard, and that the U3's keys are longer (about 40.4cm against 37.5cm), giving a touch closer to a grand.
On tone, the same dealer finds U1s typically brighter and more consistent from piano to piano, while U3s vary more โ bright, medium or mellow depending on the soundboard and hammers.
| Model | Height | Character |
|---|---|---|
| U1 | 121cm | Compact, bright tone |
| U3 | c. 131cm | Longer strings, fuller bass |
| YUS1 | 121cm | Upgraded model at U1 size |
| YUS3 / YUS5 | 131cm | Upgraded models on the U3 platform |
The YUS series sits above the U series. Yamaha's official specifications list the YUS1 at 121cm and 229kg, and the YUS3 and YUS5 at 131cm and 247kg and 253kg respectively.
Pedal configurations differ too. Per Yamaha's specifications, the YUS1 has soft, muffler and damper pedals, while the YUS3 and YUS5 have soft, sostenuto and damper pedals; specifications may vary by region, so confirm with your dealer.
The YUS3 and YUS5 share the U3 platform. Mark Goodwin Pianos describes the differences as refinements: the YUS5 has Ivorite synthetic-ivory keytops, a larger music desk, and more detailed factory regulation and voicing.
Models such as the U3H, U3M and U3A are common on the used market, and the suffix indicates the production era. According to Mark Goodwin Pianos, the U3H was made from around 1970 to 1980 with serial numbers of roughly 2,000,000 to 3,000,000; the U3M from 1980 to 1982; and the U3A mostly from 1983 to 1984.
Earlier U3F and U3G models are older still, and the dealer recommends considering them only with a full reconditioning history. Among the UX models, such as the UX-3, the defining feature is an X-shaped back brace; they date from the 1980s and 1990s.
Remember that two used pianos of the same model can be in very different condition. The year is only a starting point; maintenance history and internal condition decide the real value.
On a Yamaha upright the serial number is stamped on a gold-coloured plate inside the piano, visible when you open the top lid. Yamaha's website provides year-of-manufacture tables, including Hamamatsu serials from 1917 to 2021.
A letter prefix indicates the factory โ for example H for Hangzhou, China, J for Jakarta, Indonesia and YT for Taoyuan, Taiwan. Identify the factory first, then use the matching table for an accurate year.
Space comes first. Hong Kong homes have limited wall space, so a 121cm U1 or YUS1 is easier to place; in a larger living room, for an intermediate or advanced student, the U3's volume and bass are a real advantage.
Budget comes second. A new piano carries a manufacturer's warranty; a used one costs less but its internal condition must be checked. Whichever you choose, a full tuning and inspection after purchase is the first step to getting the best from it.
Both suit players from beginner to exam level. The U1 is more compact and fits smaller Hong Kong flats; the U3 has a fuller bass and longer keys, suiting larger rooms or more advanced students. Try both in person before deciding.
The YUS series is positioned above the U series. The YUS1 matches the U1's size, while the YUS3 and YUS5 are built on the U3 platform. The YUS5 adds Ivorite keytops, a larger music desk and more detailed factory regulation.
According to UK dealer Mark Goodwin Pianos, the U3H was made from around 1970 to 1980, with serial numbers of roughly 2,000,000 to 3,000,000. For the exact year, check the serial number against Yamaha's official tables.
Open the top lid of the upright and find the serial number on the gold-coloured plate inside. Compare it with the year tables on Yamaha's website; any letter prefix before the number tells you where it was made.
The year is only a starting point. Maintenance history, tuning-pin tightness, hammer wear and soundboard condition matter more. For older models, look for a reconditioning record, and have a technician inspect the piano before you buy.
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