It has been clear to me for some time that the interruption of LAN cables by optical fibres and media converters in digital playback systems can bring significant sonic advantages. How much more euphony one can hope for also depends on the quality of the converters. For this reason the Audiophile Grade Optical Fibre Kit was a discovery for me.

Already during the first examination of the Fibre Kit, it became clear that the set consisting of a media converter and its own linear(!) plug-in power supply has a little more to offer than a combination of the usual converter for IT applications plus a high-quality power supply, regardless of whether it comes from SBooster or Keces. With one of these two power supply units, the Fibre Kit sounds even better. I was already able to gain these impressions with a single ADOT converter, because the second one has been stranded in a UPS warehouse for a month on its way from England to Gröbenzell. In the meantime, Mika Dauphin, the head of Drei H Vertriebs Ltd, who distributes Audiophile Digital Optical Technology products in Germany, has sent me another audiophile media converter.

But before I loop the second ADOT in my system, I would like to briefly discuss the various applications for fibre optic cables. The technology was developed to be able to transmit electrical signals, such as those of Ethernet connections, over very long distances without loss - depending on the SFP adapters and suitable fibre optic cable, up to 100 kilometres should be possible. Not necessarily what music lovers need in their homes. When streaming locally stored music files, however, it has also been shown that the complete galvanic isolation of the audio components from the Internet benefits the playback quality. One possibility, of course, would be to rigorously dispense with a connection to the Internet and thus to streaming portals such as Qobuz or Tidal and to set up a separate network just for digital music reproduction. This is exactly what I did in my listening room. But thanks to galvanic isolation through simple media converters with selected SFP adapters, high-quality power supplies and audiophile Lan cables between the converters and the router or Lan switch, I can now access streaming services without compromising the playback quality of locally stored files. In my setup, a fibre optic cable of 20 metres overcomes the distance between the two converters, as the router is located in a different room than my system for good reasons. The duplex single-mode conductor thus bridges a distance that is considerable for electrical conductors, but negligible for optical conductors, and ensures complete galvanic isolation between the Internet and the network that the switch, the NAS and the streaming bridge form.