The Boston UP-120S PE II

Dimensions

Backposts
Five massive full-length laminated spruce posts. Total cross sectional area: 450 cm² (69.8 in²). Thickness of post: 9 cm (3 1/2″). Width of post: 10 cm (4″).

Backframe
The massive backposts are tenoned into upper and lower mortise rails, creating a substantially strong frame. Backpost locations are staggered for proper support. Solid filler blocks and maple backboards make this back frame assembly even stronger. A grand-style hardwood closing rim is attached to this foundation, onto which the soundboard and ribs are glued. This structure provides unequaled strength and stability and improved acoustics.

Pinblock
Octagrip™ pinblock made of 11 layers of hard rock maple – glued in different grain angles of 60 degrees – affording the tuning pins greater stability under tension and enabling the piano to stay in tune longer.

Soundboard
Close and straight-grain solid (not laminated) spruce. Minimum 3 annual growth rings per cm (minimum 8 per inch). Tapered from treble to bass, to provide a rich tone in the bass, and a brilliant and crisp tone in the treble, creating a well-balanced and lasting tonal response. Tapered from 9 mm to 8 mm. Vibrating area: 1.11 m² (1,721 in²). Closing rim evens out the soundboard’s response to all frequencies, eliminating “hot” spots. Emulates shape of grand soundboard.

Ribs
Made from durable spruce to assure strong and constant support of the strings bearing down on the soundboard. Ribs are fully let-in to the liner to support the important soundboard crown and prevent the piano from losing its tone. Number of ribs: 11

Bridges
Treble: Vertically laminated hard rock maple with a solid maple cap, curved to fit the crown of the soundboard. Bass: Solid maple mounted to cantilevered base. Doweled, glued, and screwed to soundboard.

Scale
Overstrung: Lower tension scale for longer sustaining tone, beautiful tonal clarity and depth, and longer life of the whole piano. 16,006 kg (35,213 lb) tension.

Plate
Cast from grey iron, bronze-painted and lacquered.

Tuning Pins
Nickel-plated steel, cut threaded.

Strings
Treble: Highest grade steel (in half size increments). Number of sizes: 10. Lowest tenor note: 29. Bass: Steel core wire wound with solid copper. Number 1 speaking length: 110.0 cm (43.3″)

Hammers
Premium German Würzen topfelt over premium wool underfelt, pressed over hornbeam moldings into Steinway & Sons shape, compression-wire reinforced; hammer-shanks from select resilient horn-beam; resulting in superior tone, increased durability and greater voicing ability.

Action
Solid maple (all wood, no plastic) for all moving parts. Extruded aluminum action rails for increased stability and less frequent regulation. Dependable direct-blow design.

Keys
Solid spruce, individually balanced and weighted. Phenolic sharps and acrylate white key covers. Length of key: 39.2 cm (15.4″)

Keybed
Made of spruce and birch. Strong, rugged construction provides a solid mount for the keyframe and action allowing for precise and prolonged action regulation. Keybed thickness is 42 mm.

Keyframe
Spruce with hardwood inserts in the balance rail and front rail for added stability.

Pedals
Soft (half-blow), muffler, and sustain (damper) pedals.

Other
Music desk: Professional music desk. Casters: Double-nylon casters. Locks: Fallboard and top locks. Prop Sticks: Top prop sticks. Bench: Matching wood-top bench.