How to Implement +6db on dsf:wav transcode?

[Roy Boy]

I am ripping vinyl albums to DSD128 (DSF) and then using minimstreamer to transcode to wav 24/384 since my Lumin A1 cannot play DSD128. (only DSD64). The output level of these transcoded DSD128 files is too low. I am trying to implement the +6db gain option. I am using Miniwatch - Properties then select System tab. On the stream.transcode field I tried the following:

dsf:wav24;384, flac:wav+6db

but this gave me a syntax error. Can you point me at where I can input this +6db option correctly? Thanks