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Post by John on Jun 19, 2024 6:26:45 GMT
Glad it's working well
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Post by MartinT on Jun 19, 2024 6:36:58 GMT
Can someone please explain how you can connect these up. I can see this is not a ethernet connection and at present it does not make sense to me. A DAC is a passive copper twinax (twin axial) SFP+ ethernet cable designed for connecting equipment with SFP cages, such as the EtherREGEN and Signature Rendu Deluxe. The idea is that, for short distances, they can outperform an optical cable and use much less power, effectively running cool. There are also no electronics in a passive cable, so no laser, receiver, triggering circuit etc. DAC cables only make sense for equipment with an SFP cage and for short runs. |
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Post by MikeMusic on Jun 19, 2024 8:34:48 GMT
Confirmation of understanding for the hard of understanding - me
Just plug in and use
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Post by MartinT on Jun 19, 2024 8:44:17 GMT
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Post by MikeMusic on Jun 19, 2024 10:34:38 GMT
Will do !
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Post by MartinT on Jun 19, 2024 10:49:38 GMT
Remember: EtherREGEN powered up first, before Rendu.
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Post by Clive on Jun 19, 2024 10:54:27 GMT
Presumably what we are now doing with the DAC cable vs AOC is to forego the galvanic isolation of fibre for a direct cable connection. This trades off isolation vs jitter from lasers etc.
Effectively are we now doing something very similar to using a switch but just via a protocol converter vs switching signals/cables? So simpler than a switch.
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Post by MartinT on Jun 19, 2024 11:07:49 GMT
Effectively are we now doing something very similar to using a switch but just via a protocol converter vs switching signals/cables? So simpler than a switch. Agreed, but remember this only works because the EtherREGEN has an extremely good, low noise flip-flop at its feed to the SFP cage, further enhanced with an external clock. It also has the galvanic isolation moat. The DAC cable is going to pass this through hopefully unmangled. Since we are using our EtherREGENs 'backwards', from B to A side (because it only has one SFP cage), it's still not as low noise as it might be. This is where I look forward to EtherREGEN Gen 2, because we'll be able to use it right-way-round with an SFP cage on the B side and further improved noise levels. |
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Post by Clive on Jun 19, 2024 11:12:17 GMT
Effectively are we now doing something very similar to using a switch but just via a protocol converter vs switching signals/cables? So simpler than a switch. Agreed, but remember this only works because the EtherREGEN has an extremely good, low noise flip-flop at its feed to the SFP cage, further enhanced with an external clock. It also has the galvanic isolation moat. The DAC cable is going to pass this through hopefully unmangled. Since we are using our EtherREGENs 'backwards', from B to A side (because it only has one SFP cage), it's still not as low noise as it might be. This is where I look forward to EtherREGEN Gen 2, because we'll be able to use it right-way-round with an SFP cage on the B side and further improved noise levels. I’m not using an EtherREGEN (yet) but I hear similar results. When I have more miles on the DAC I’ll swap back to the AOC. I have been using the Tara Labs track. |
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Morph
Rank: Duo
Posts: 62
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Post by Morph on Jun 19, 2024 13:06:56 GMT
Well this looks like another interesting find by MartinT so a 1M Gnodal will be arriving in a few days.
Thanks again Martin!
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Post by orange55 on Jun 19, 2024 13:25:53 GMT
As I write this I wonder if MartinT this topic needs to be pulled to a separate DAC thread rather than clogging up yours? My use case does not include the Ethergen, instead I have two SOtM switches connected via the SPF link. I currently have the Cisco AOC in place. I have in the past tried using Ethernet to connect the two switches as SOtM recommend. But even with a high end Ethernet the Cisco fibre sounds better, a slightly quieter background. However, am interested to see if the SPF slots are engineered differently to the Ethernet ports on the SOtM or if this DAC benefit specific to the Ethergen use case. |
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Post by MartinT on Jun 19, 2024 14:03:55 GMT
As I write this I wonder if MartinT this topic needs to be pulled to a separate DAC thread rather than clogging up yours? Good idea - done! |
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Post by Slinger on Jun 19, 2024 15:47:37 GMT
I just wish they'd use a DAC to avoid confusion on audio threads. Sorry. That's DAC. Different Acronym Configuration.
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Post by MartinT on Jun 19, 2024 16:22:03 GMT
Oh, I thought it was Diffused Air Coefficient.
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Post by mattspl on Jun 19, 2024 17:57:09 GMT
My DAC cable arrived, but doesn’t seem to work. I’ll try again in a little while.
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Post by MikeMusic on Jun 19, 2024 17:59:07 GMT
Keep us posted
Especially as you might solve a problem I have yet to have
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Post by MartinT on Jun 19, 2024 18:12:41 GMT
The gnodal seems to have reached its (very high) plateau, so I quickly substituted the FS for a listen. Pretty good, but a little polite and not as epic sounding as the gnodal. Guess my nose for good performance survives as I had an inkling that it (the gnodal) just looked a better cable physically and on paper. It also seems to be discontinued so you'll have to scour eBay if you want one.
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Post by mattspl on Jun 19, 2024 20:55:17 GMT
It seems you’ve to configure the Cisco switch ports to SFP as you have an rj45 and sfp port beside each other with the same number.
I configured the port, but get a CRC error.
It seems either the switch software is too old for the DAC cable, or the cable isn’t compatible , although the switch recognises it.
Can anybody shed light on this?
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Post by MikeMusic on Jun 20, 2024 8:07:36 GMT
Thought it was just plug in and go
Someone who knows what they are talking about will be along soon I hope
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Post by MartinT on Jun 20, 2024 8:29:06 GMT
The only light I can shed is that the connection link speed will set according to the first end to be powered up. I am always careful to power up the EtherREGEN first and let it settle, then powering up the Rendu will acquire the same operational speed. Comms established and all is well.
For other equipment, you may need to try it both ways.
EDIT: another trick you can try, which I've also done, is to establish a good link with a working cable - say, an AOC. Then hot-swap the DAC cable in without turning off the gear. These cables are hot-swappable, so it should work and the new cable will work at the same link speed as the old one.
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