I
Itai Tavor
- Jan 1, 1970
- 0
Hi,
I have a computer with a coax S/PDIF output, and I want to add an
optical output. The coax->optical conversion is easy
(from http://www.epanorama.net/documents/audio/spdif.html):
+----------------------------------------------- Coax
| Out
------- | +--10K--+
| | 10 nF | | -------
Comp. | ------- | || | |\ | |\ | |
S/PDIF |-----------+---||---100R--+--| O--+---+---| O---|TOTX179|--
Optical
OUT | ------- | || |/ | |/ | | Out
| 5cm 75R 10K -------
------- coax | 74HCU04 |
--- ---
But I'm usure about termination issues. First, how does the short coax
from the computer affect the termination of the output? Is the 75ohm
still needed? And with that resistor in the circuit, the termination is
messed up when a coax output cable is plugged in - how can I deal with
that?
I don't want to use a manual switch to select one of the outputs, and
I'd use an RCA socket with an integrated switch if I could find one, but
I can't.
Any advice?
TIA, Itai
I have a computer with a coax S/PDIF output, and I want to add an
optical output. The coax->optical conversion is easy
(from http://www.epanorama.net/documents/audio/spdif.html):
+----------------------------------------------- Coax
| Out
------- | +--10K--+
| | 10 nF | | -------
Comp. | ------- | || | |\ | |\ | |
S/PDIF |-----------+---||---100R--+--| O--+---+---| O---|TOTX179|--
Optical
OUT | ------- | || |/ | |/ | | Out
| 5cm 75R 10K -------
------- coax | 74HCU04 |
--- ---
But I'm usure about termination issues. First, how does the short coax
from the computer affect the termination of the output? Is the 75ohm
still needed? And with that resistor in the circuit, the termination is
messed up when a coax output cable is plugged in - how can I deal with
that?
I don't want to use a manual switch to select one of the outputs, and
I'd use an RCA socket with an integrated switch if I could find one, but
I can't.
Any advice?
TIA, Itai