JBK's input voltage can exist plus or minus 5% so his input will have 3 heads 361v 380v and 399v
BK's output voltage is fixed, for example, for 36v, his output has 36 24 12 6 which are the 4 voltages
And JBK is generally changed according to the user's needs, not necessarily the above voltages. And the power of each voltage of jbk is also fixed after the factory, so there is a difference with bk
If your requirements are not too high you can substitute, but it is better not to. You can order according to your needs and the manufacturer, jbk generally will not have the exact same stock. If you are in a hurry, it is recommended that you use a higher power BK transformer. Prevent the transformer from burning out!