Since 1986, Challen pianos have been assembled in western Malaysia by Musical Products Sdn. Bhd, the factory division of Vienna Music Sdn. Bhd.
Dates and serial numbers when the pianos were manufactured
| 1850 | 3200 |
| 1860 | 6100 |
| 1870 | 9650 |
| 1880 | 14220 |
| 1890 | 19480 |
| 1900 | 26260 |
| 1910 | 31309 |
| 1920 | 35814 |
| 1930 | 43205 |
| 1940 | 66482 |
| 1950 | 73043 |
| 1960 | 87529 |
| 1970 | 95069 |
| 1980 | 103337 |
| 1990 | 38787 |
| 2000 | 45972 |
