Hi... my Lynx PCIe card allows me to change its digital I/O from AES to SPDIF via a jumper on the circuit board. I have the Lynx digital I/O breakout cables but they terminate to 3-pin XLR. So, in order to connect the digital signal to my Topping DAC's RCA coax connection, I need to build a short length XLR to RCA adapter cable. Lynx offers one (see pic) but since I already have a Monoprice 75 ohm RCA coaxial cable I'm not using, I thought I'd splice it and connect the other end to a female XLR jack.
Could someone help me with wiring the XLR side of the cable? I've seen a few diagrams online but I'd like to get the information here.
Thanks
Could someone help me with wiring the XLR side of the cable? I've seen a few diagrams online but I'd like to get the information here.
Thanks
Is there any indication what this switch does: only change some subcode bits or also change impedances and levels?
When those subcode bits don't matter, like for most DACs, you normally interface an AES3 output to an S/PDIF input with a special transformer and a few resistors. If the output is already transformer-coupled, you might be able to get away without the transformer.
When those subcode bits don't matter, like for most DACs, you normally interface an AES3 output to an S/PDIF input with a special transformer and a few resistors. If the output is already transformer-coupled, you might be able to get away without the transformer.
In the digital realm, I don't think a single end to differential cable adapter is a good idea. Here, the frequencies start to get so high that these things do matter. You have probably seen how to hook up these connectors for analog... I suggest you stick to the same type interface in both ends for best results. And if you have opto/toslink - try that 😉
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It seems Lynx has 2 almost identical looking XLR-RCA adapter cables so it is possible they are wired differently. Hot wire (XLR pin 2 to RCA center) should be the same but cold wire connection may be different. But likely only 3 possibilities for cold wire: pin 3 to RCA shield (as in picture), pin 1 to RCA shield, pins 1 & 3 to RCA shield.
I'm just surprised they don't do anything special for the 110 ohm to 75 ohm transition and the roughly 10 times lower S/PDIF signal levels. Maybe they handle that on the board depending on the switch setting, but then the characteristic impedance of their breakout cable is incorrect. Maybe it's electrically very short so it doesn't matter much.
Difference in levels is probably the bigger issue. Most SPDIF receiver chips can manage 5V input and with input termination the level should be even lower. Maybe Lynx has a resistor divider built in to the adapter cable.
As the price of the cable is 16 USD from Lynx I don't see much benefit in building diy cables.
As the price of the cable is 16 USD from Lynx I don't see much benefit in building diy cables.
If the signal thru the Lynx digital I/O breakout cable is actually S/PDIF.
Then the small 75 to 110 Ohm mis-match of an XLR connector won't matter.
In fact, you could send a S/PDIF signal thru a 5 meter (15 foot) AES3 cable without a problem.
Then the small 75 to 110 Ohm mis-match of an XLR connector won't matter.
In fact, you could send a S/PDIF signal thru a 5 meter (15 foot) AES3 cable without a problem.
Hey thanks for posting that. I got a response from Lynx today and that's exactly the diagram they sent me. I'm not sure if it's viable for Audio connections but it is for S/PDIF connections.
