OP-1 - quick start guide April 21, 2021 13:01 Updated here is the OP-1 quick start guide and here is a downloadable pdf. Related articles OP-1 - overview [video] can i purchase a replacement battery from teenage engineering? OP-Z - additional settings, general.json config options explained. (how to get backlit keys, etc.) OP-1 and midi OP-1 - what is the maximum charging current with which OP-1 should be charged at 5V?