Using fibre optics to break ground level noise

I recently changed my Etherregen from ethernet to fibre by adding a Gustard N18, two Finisar 1318 SFPs and 30cm Gtek single mode LC fibre. The Etherregen continues to be connected to the streamer via RJ45. The double conversion resulted in a nice opening up of the sound stage and lowering of the noise floor. The real kick though came from adding a 10db attenuator to the fibre connection. Suddenly another nice improvement in soundstage size but incredible impulse and decay response with lots of additional micro detail.

My lay man’s explanation is that short runs of fibre overload the SFPs which are built for longer fibre runs and hence more attenuation. In any case well worth the experiment