offset between preview and master

Hello,

Welcome to the forum.

I do not understand some words in the message:
1) offset: do you mean a delay (time difference = time gap = latency) or do you mean an audio difference, then please define this sound difference (do you mean a glitch, a difference of volume...)
2) in "as soon as I turn up the volume of the latter", does the "latter" refer a deck or does it refer to the speakers, or to the headphones?
If you natively speak french, it may be easier to switch to the french part of the forum.

For the technical information itself, please:
- never post twice the same message at the same time (most forum instantly ban the user account, at double post a bot behaviour and it is not authorized in the term of use of any forum) as synchronizing 2 discussions on the same subject on the same forum is a nonsense
- for ANY technical questions, you should complete your technical profile on