I’ve just come across something new to me. I have previously seen the SFP connections on Melco and other equipment as optical ports but they are dual purpose. Melco are recommending a direct attach copper cable. Naturally they sell one at premium price 
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Has anyone experience of this form of connection for audio purposes or any observations ( beyond “all cables sound the same”) ?
Hi Pete, I compared this new Melco cable to both Ethernet and optical SFP/SFP+ cables between my Melco N1 S38 and a S100 switch.
Ethernet works ok, optical is better.
However the level of detail and bass control is even better with the new Melco SFP+ cable.
It is not really cheap, but shure worth it.
Cheers
Dirk
Melco is not an optical cable, it is a DAC cable. AOC cables are optical.
A Direct Attach Copper (DAC) SFP/SFP+ cable is a twinax copper cable with factory terminated transmission modules. Utilizes direct electrical connections (hence the name Direct Attach Copper)
Passive DAC cables have no electrical components built into the cable assembly. They operate based on simple electrical transmission: when an SFP/SFP+ port generates an electrical signal, the passive cable directly transmits this signal from one end to the other without any additional processing or signal amplification. The SFP/SFP+ completely bypasses the need for the PHY interface
They employ differential signaling to counteract electromagnetic interference by transmitting the positive and negative signals across paired copper wires
The Direct Attach Copper (DAC) SFP/SFP+, is constructed and designed to build with tightly controlled impedance, tested to manufacturing at 100 Ohms, without any impedance mismatch
These cables maintain excellent signal integrity over short distances, benefiting from reduced potential failure points and the absence of required signal conversion
If you want the best:
Amphenol SFP+ 10GbE direct attach passive copper cable (DAC), quad-shielded 30 AWG twin-axial SKEWCLEAR wire (SF-SFPP2EPASS-002)
Torben
It’s true that DAC cables are simpler than AOC cables and don’t include potentially noisy conversion devices (transceivers) which the latter do. But it’s important to note that many people who use devices with SFP ports did so precisely to get the benefits of an optical break in their playback chain. As ever, which we choose is system- and taste-dependent. Both approaches have their technical pros and cons and both have their advocates but for me it’s AOC hands down. I tried a Cisco DAC cable in my own system and it was horrible; I doubt others would have preferred it but hey, who knows?
Thanks, Torben.
Are you German as well?
If you read my post you will find a ranking of 3 cables I compared:
LAN, optical and the new Melco SFP+.
The latter certainly is not an optical connection, no question.
Thanks
Dirk
“Almost” 
I am a Dane living in Hamburg for more than 25 years.
Torben
If someone wants to try a DAC cable, please stick with the passive version. The active DACs (not to be confused with active optical cables, “AOC”) have a number of additional circuits for signal conditioning, amplification and equalization. This contradicts what you want to achieve with the simple LVDS connection.
Torben
Did you change your mind?
These are passive DACs:
Their brochure about the Skewclear wire is worth reading:
https://www.mouser.com/datasheet/2/18/1/New%20SKEWCLEAR%20Brochure%202-25-02-8977.pdf
Torben
