[mythtv-users] SPDIF Brackets building them for sale

[David George]

On 12/21/2007 9:07 PM, Mitch Gore wrote:
> On Dec 21, 2007 7:50 PM, Scott Pleavin <scott.pleavin at rogers.com 
> <mailto:scott.pleavin at rogers.com>> wrote:
>
>     Would you need the same resistor and capacitor on a S/PDIF input?
>
> I have one that i built.  I didnt use any resistors or any thing.  It 
> has worked for the last 1.5 years.

Your receiver must be tolerant of 5v input then.  The S/PDIF spec says 
the data should be 1v peak to peak.  The PC output is usually TTL level 
which is 0v to 5v.  This is why the capacitor resistor circuit is used.  
The only requirement is that the PC must have enough current output to 
drive the circuit.  If it doesn't you will need to use a more 
complicated circuit that includes a buffer chip.

Also, there is an error in the capacitor/resistor circuit I posted 
yesterday.  The capacitor should be 100nF as Adilson wrote.

-- 
David