WAØSXV IC-7800 -- Getting optical digital sound interfaced

Last update:  03/08/2005 16:31:47 -0700

The IC-7800 has the capability of interfacing to audio equipment via the S/P DIF standard.  This capability is very poorly documented and no cables are supplied.

Devices using S/P DIF can be interconnected using either coaxial or optical cables.  After looking at the photographs of the back panel of the 7800 I concluded that it used optical interfacing.  This seemed like a great idea since it prevents ground loops and RFI, in additional to providing a very high-quality interconnect.

Next step was to find a sound card that supported this.  After reading JA7UDE's 7800 diary page, I decided that a Creative Sound Blaster MP3+ with USB interface would be a good choice.  The price was right (remember -- this might not even work) and by using USB instead of PCI it should be compatible with future computer upgrades.

So -- where does one buy the optical cables?

After further research I discovered that the optical interfacing is called TosLink.  So I searched Google for, and found, inexpensive fiber optic cables.

Sounds simple -- right?

Look at these cables (right).  Notice that the ends look different.  In particular, the lower connector has some kind of bulbous plastic covering.  Actually, both of them had this covering.  Without any instructions on use of these cables, I didn't realize that the covering was actually a protective cover that should be removed before use.  So when the sound card arrived, I blithely tried to plug the cable into the S/PDIF output jack.  It could be forced in (I know -- dumb move) but didn't fit well.  Worse, it didn't seem to matter which way the connector was inserted.

I eventually discovered that the plastic cover could be removed.  Still don't remember how I discovered this.  Once I removed it, the connector fit much better.  Unfortunately by then I had somewhat damaged the socket mechanism.

I was able to more-or-less repair the socket on the SB board and the final result is shown on the left.  The plastic protective cover must be removed and then the connector is inserted with the arrow on the top.  It would have been nice if either Icom or Creative had documented the proper use of the optical cables.