21. What are the differences between the DM15 R2R and the DM13?

Why does the DM15 R2R have a lower output level than the DM13 at the same volume setting?

Based on feedback from some DM13 users, the DM15 was adjusted to better suit highly sensitive in-ear headphones, which could sound excessively loud too quickly with the DM13. Therefore, the volume curve of the DM15 is designed to be more gradual in the lower range, increasing more rapidly only in the higher volume stages.