alexreusch

Just check the specifications of your SFP's on the Cisco website. You might be just fine, depending of the specs. If you are using Cisco 1000BASE-LX SFP's, then the specs say: -3 to -9.5 dB for Tx and -3 to -20 dB for Rx with a maximum channel insertion loss of 6 dB. The same for BX modules, even if the specs are different. The situation looks different when using EX or ZX modules. Here you will need attenuators.

Thanks for clarifying. That's exactly what I was trying to explain. If you select randomly a single mode SFP, you could end up with using stuff outside of the supported specifications. This is what my example was showing: This specific SFP (Cisco 1000BASE-ZX) cannot be used for short distances of a few meters, without adding an inline optical attenuator. So if somebody bought single mode SFP's without knowing the specs and it worked, than all I can say is: Lucky guy!

OK. But then I would suggest you to try an original Cisco SFP, as this is the real deal: https://www.connection.com/product/cisco-1000base-zx-sfp-smf-1550nm-dom-transceiver/glc-zx-smd/15392887 Jokes aside, using single mode over short distances can be counter productive. When shorter distances of single mode fiber (SMF) are used, it might be necessary to insert an inline optical attenuator in the link to avoid overloading the receiver. Keep in mind: single mode fiber is made for very long distance situations. Have a look at the Cisco documentation here: https://www.cisco.com/c/en/us/products/collateral/interfaces-modules/gigabit-ethernet-gbic-sfp-modules/datasheet-c78-366584.html The 1000BASE-ZX module in my link above (specified for distances of up to 70km) has a transmit power range (dBm) of +5 to 0. But the maximum receive power range (dBm) is -3 to -23. For single mode fiber, the attenuation (signal loss) is about 0.4 dB per km for 1550 nm. So in this case, just to be on the save side, the minimum cable lenght would be 20km!!! According to the documentation, A 10-dB inline optical attenuator should be inserted between the fiber-optic cable plant and the receiving port on the SFP at each end of the link whenever the fiber-optic cable span loss is less than 8 dB. Funny isn't it? That's exaclty the attenuation for 20km. 😀 As you can see, you cannot just use any SFP and cable length without knowing the specifications. My suggestion would be to use the fiber type appropriate to the application. For distances of 550m or less, use multimode.

No, the cables don't make any difference on audio performance. The idea of going optical is to get galvanic isolation which prevents electrical noise to get into the opticalRendu. The optical solution does this perfectly, independent which cable type or SFP's you are going to use. It delivers digital data free of any electrical noise, which can then be processed by the optidalRendu. All you have to take care about cables and SFP's is, that they match. You cannot use a multimode cable with a singlemode (monomode) SFP and vice versa. The difference between all those cables and SFP models is in general the maximum cable length. Single mode uses a high precision laser and longer wavelength, which allows cable lengths of many kilometers (and miles). I would assume that this is normally not needed. I think most of us can live with cable lengths of 10-20 meters and therefore, multimode is just fine. The multimode SFP that comes per default in the opticalRendu is a tp-link SM311LM, which works fine with multimode cables with 62,5 micron core diameter (up to 275m cable lenght) as well as 50 micron core diameter (up to 550m cable length). I think this should be just fine for most of us. There will be no benefit going with single mode, other than being able to go for larger distances. But it's still a digital signal (perfect galvanic isolated). As long as you are staying within the specified limits, they will deliver all the same results (0 and 1's).

Hello, I saw the list of recommended Power Supplies and in general you recommend all PS to be set on 7VDC. However, there is only one Power Supply that has lower settings, the Sbooster to be set on 6VDC. I know that Sbooster does currently not offer any Power Supply with 7VDC, but it is still on the list of recommended PS. Is there any negative impact running at 6VDC vs. 7VDC? What is your opinion on it? It is also possible to set the Sbooster to 6.5VDC.Would that be better than 6VDC?

The external power supply of the opticalRendu is a very critical part. How do you rate the importance of the external power supply for the opticalModule? Same or less important as for the opticalRendu? Why?

Thanks for your opinion. I also think that that the opticalRendu should have a near perfect USB output. I just thought that the ultraDigital is a product from sonore as well, which has been designed to work optimally with the ultraRendu. But maybe this improvement is becoming obsolete with the opticalRendu. As you said: every additional component...

Do you see any added value of the ultraDigital using I2S behind the opticalRendu? I mean, the USB output of the opticalRendu should be close to perfect, not? If a DAC has a very good USB input (PS-Audio), don't you think the extra box (ultraDigital) will be obsolete?

Thank you! Problem solved. It was a switch port problem, that was flip/flopping. I had to use another port on the switch and it is now working again. Thanks for the fast reply.

I had a Micro Rendu working for some time, but now it does not appear anymore under Network Players when I go on the Sonicorbiter Homepage. Unplugging and replugging power does not help. The device seems dead. Any idea how to troubleshoot? Is there a way to get customer support?

I tested yesterday native DSD 256 with my NuPrime HD-AVP. I works perfect and sounds really great. That's the best listening experience I ever had. Thanks for your support!

Native DSD support under Roon for Nuprime HD-AVP status is on: pending update Is there already some software update available? Maybe a beta to test? Can I help out here? I do own the HD-AVP and could test, if required. Let me know.