I noticed that the isabella has a bnc imput which is what I would have to use. Can a standard rca jack be substitued in the factory? If not, do you know of any high quality bnc to bnc or bnc to rca cables? Just curios why the bnc connector was used instead of a high end 75ohm rca input. Any reply is appreciated.
Hi KingStyles,
The coaxial input on the Isabellina dac is a high-bandwidth, 75-ohm BNC jack. We also include a BNC (male)-to-RCA (female) adapter in the box for those who do not use a source with a 75-ohm BNC output jack. Unfortunately, most sources use RCA, but RCA is usually a 50-ohm jack (and it is not a precise impedance. Nor are the RCA plugs). Ideally, you would replace the RCA coax output of your source with a 75-ohm BNC jack, and then use a 75-ohm BNC-to-BNC cable.
For transmitting S/PDIF, 75-ohm is the specified impedance from source to dac. I have found that using a source with a 75-ohm BNC output, a 75-ohm BNC-to-BNC cable, and a dac (such as the Isaellina) with a 75-ohm BNC input jack (and we follow this with a 75-ohm digital isolation transformer) gives best results for transmitting S/PDIF.
However, you can still get good results with RCA cables and using the BNC-to-RCA adapter (but this is not optimal!).
I do not offer BNC-to-RCA cables, but I do make really nice sounding 75-ohm BNC-to-BNC cables (3 feet) and can include a BNC (female)-to-RCA (male) adapter for them.
Best regards,
Vinnie
