I connected my headphones to the MA400 via an extension cable and had no problems with the signal. Only that the jack is prone to loose contacts (had to exchange my first copy).
Hi,
Then there is probably something wrong with the extension cable or its plug. Even with a 10m extension cable, the headphones will not normally sound noticeably quieter. Have you ever tested another extension cable?
Thank you for pointing this out, the wrong images were effectively stored there. Unfortunately, we do not receive the white version. If you have bought the product, you can of course return it without further ado.