Popular Post JohnSwenson Posted December 29, 2018 Popular Post Share Posted December 29, 2018 Let me try and address some of these questions without giving away too much. In the ultraRendu the Ethernet port from the iMX6 is connected to an Ethernet PHY, which talks to a very high quality Ethernet jack with built in magnetics. The PHY is directly connected to the "outside world" which leaves it somewhat susceptible to the signal integrity of whatever is connected to it. In the opticalRendu I re-designed the Ethernet circuit. I'm not at liberty to discuss the details of this circuit. What I can say is that this circuit uses a ton of very high quality voltage regulation and very low phase noise clocking. The result is that the processor is fed a signal that is cleaner than any external Ethernet connection you can buy today. This circuit is the primary new addition to the opticalRendu and is where the additional oscillator is used. Using an optical network connection provides a remarkable synergy with this circuit allowing it to produce such a clean output to the CPU. As has been mentioned other parts of the opticalRendu have been significantly improved as well. That's as much as I can say right now. John S. Ralf11, TwinPeak, feelingears and 3 others 2 1 3 Link to comment
Popular Post JohnSwenson Posted December 29, 2018 Popular Post Share Posted December 29, 2018 A RJ45 SFP module WILL work, as long as it is NOT a 10/100/1000 one, it HAS to be JUST a gigabit module. These modules do not block leakage currents from the network. The optical does. How much this is going to effect the sound is of course dependent on the network setup. Another issue is the difference between an optical and Ethernet SFP module. The optical module is very simple, the incoming light from the fiber goes to a high speed photo diode, then to a simple amplifier. The output from the amplifier goes to my circuit. All the signal conditioning and clocking, protocol conversion etc is done in my circuit which uses very low phase noise clocks, extremely clean power etc. With a RJ45 SFP the clocking and conversion circuits are all done with whatever is in the SFP module, I can guarantee it is not as good as what is in my circuit! The signal from the RJ45 SFP still goes through my circuit which can clean it up some, but it's not as good as what I can do with the optical signal. So an opticalRendu with an RJ45 SFP WILL be better than an ultraRendu fed by the same Ethernet cable, the opticalRendu fed by an optical signal is significantly better. John S. feelingears, gstew and rickca 1 2 Link to comment
JohnSwenson Posted December 29, 2018 Share Posted December 29, 2018 The SFP module is off the shelf. John S. gstew 1 Link to comment
Popular Post JohnSwenson Posted December 30, 2018 Popular Post Share Posted December 30, 2018 The SFP cage side of the SFP module is standardized, same physical, same electrical and same protocol. The part where you plug in the fiber can be different. There are two common wavelengths, usually referenced as SX and LX. There are two different types of fiber: single mode and multi mode. So any optical SFP module will work with any SFP cage designed for optical use (which is pretty much all of them). You DO have to match the fiber side. Use an SX to SX, LX to LX, single mode to single mode and multimode to multi mode. If you have an SFP cage on both sides, its easy just use the same model SFP module on both sides and use a cable that matches. If one side is an FMC with a built in optical interface (ie NO SFP cage), you need to find out what it is and get an SFP module that matches. As to which of these combinations sound better, who knows. But be careful, LX is designed for much longer range, but that doesn't mean it is going to sound better between two boxes in the same rack. There are some people that think LX is actually bad for very short lenghts, the electronics are designed assuming a lot of attenuation due to the long fiber length, with a short cable that does not exist and are probably putting the receivers in a state they were not designed for. It may or may not make any difference, I have not spent any time comparing different combinations, other than do they WORK. John S. feelingears, TwinPeak, d_elm and 2 others 2 3 Link to comment
JohnSwenson Posted January 3, 2019 Share Posted January 3, 2019 1 hour ago, octaviars said: I assume @diecaster your question is a follow up to me writning that I wait for the etherREGEN. You dont need a etherREGEN if you have a opticalRendu I have a different layout of my system and needs a switch that connects to my Roon core and Roon endpoint. This is not necessarily true. Phase noise from upstream clocks DOES pass through optical cables as well as copper cables. The prime reason for the EtherRegen is that it blocks this upstream phase noise. So it may still provide some improvement with an opticalRendu. You may hear the difference, you may not depending your system. So I would not say there is guaranteed to be no advantage of the EtherREGEN if you have an opticalRendu. It's going to have to be a try it and see. John S. Link to comment
JohnSwenson Posted January 3, 2019 Share Posted January 3, 2019 11 hours ago, Em2016 said: So this means the opticalRendu won't feature your 'Clock Blocking' feature? Correct, first off it is still in development, it is very expensive, it takes a lot of room. The upshot is that to put it in an opticalRendu would mean a bigger case, Two power supplies, and cost a LOT more. This did not seem like a good way to go for something that may or may not make a difference depending on the users system. John S. asdf1000 1 Link to comment
JohnSwenson Posted January 4, 2019 Share Posted January 4, 2019 The opticalRendu runs at gigabit, period. It will not run at 100Mbit or 10G. The technical details are that the protocol used by most of the optical SFP modules runs at gigabit without auto-negotiation. Theoretically it could run at 100Mbit, but without auto-negotiation there would have to be a switch to select which speed. I considered that to be way too confusing for most situations. There is a different protocol that runs over SFP that DOES implement auto-negotiation so it can automatically deal with different speeds, but the number of modules that use this protocol is very small. The problem is that it is very difficult if not impossible to tell which type of module you have. So it was decided to make it work with just the vast majority of modules which will be what most users will be using. John S. MikeyFresh 1 Link to comment
JohnSwenson Posted May 23, 2019 Share Posted May 23, 2019 57 minutes ago, R1200CL said: @vortecjr or @JohnSwenson What’s you best guess about this one. I expect it to work, since fiber side is 1000 Mbps, but it has also been said 10/100/1000 types won’t work. https://planetechusa.com/gt-805a-10-100-1000base-t-to-minigbic-sfp-converter/ This should work fine. The 1000FX is the SFP side (it is the gigabit fiber mode, which is what the opticalRendu supports). The 10/100/1000 is the RJ-45 Ethernet side which is normal. The problem is when you plug in an SFP Ethernet module into the SFP cage. As long as the SFP module you plug in is gigabit optical you are fine. John S. R1200CL 1 Link to comment
JohnSwenson Posted May 23, 2019 Share Posted May 23, 2019 1 hour ago, sahmen said: These useful caveats are highly appreciated, especially by someone like myself with clocks of impatience that often need to be held at bay in such initial auditioning processes 😀 I heartily agree with Barrows, it takes at least 24 hours for one of these to start to come close to what the ultimate sound will be. After 48 hours they will be getting pretty close. John S. Link to comment
Popular Post JohnSwenson Posted May 24, 2019 Popular Post Share Posted May 24, 2019 52 minutes ago, Em2016 said: Hi @JohnSwenson Without going into nitty gritty details, what was the biggest challenge going from copper ethernet (like ultraRendu) to optical? Is it the higher jitter often talked about? Is it significantly higher jitter? Cheers What higher jitter? You might be thinking about the Toslink connection, which does have higher jitter than electrical S/PDIF interface, but this is not universal. If done right, (not all that often) the optical talked about here which is gigabit data CAN be done with very low jitter, you just have to pay attention to details and not use the cheapest parts possible. It was not particularly hard, just the usual understanding the problem so an optimal set of parts can be chosen that give the best performance for reasonable cost. By far the hardest part was getting the Ethernet coming out of the CPU module to talk with the circuit that generated the signals going to the SFP module. Both of them were designed to talk to something like a switch, not to each other. It took a LOT of work to get those two to talk to each other. The solution turned out to be very advantageous, it significantly cut down on the noise generated by the PHY in the CPU module. John S. barrows, asdf1000 and rickca 3 Link to comment
Popular Post JohnSwenson Posted May 24, 2019 Popular Post Share Posted May 24, 2019 21 minutes ago, Em2016 said: Thanks for the info John. I’ve seen people in the past suggest the conversion process from optical ethernet to copper ethernet may be high in jitter. So was wondering if it was similar going from optical ethernet to USB (is there a conversion to copper ethernet in between ?) The optical is converted to a simple high speed protocol inside the SFP module,, The electrical signals from that go into a circuit that converts that simple protocol into the much more complex Ethernet protocol, those wires go into the CPU module in place of the Ethernet RJ-45 jack. The rest of the circuit is similar to an ultraRendu, I did improve the power and clock network. John S. asdf1000, rickca and barrows 2 1 Link to comment
JohnSwenson Posted May 25, 2019 Share Posted May 25, 2019 1 hour ago, cat6man said: KEY POINT: those of you who have received your units, why are there no reviews of audio quality???????????? A few posts back we told people it takes 24-48 hours to get into the really sounding good state, maybe everybody is taking that to heart? Although wend could audiophiles ever WAIT when they have new gear. John S. Link to comment
Popular Post JohnSwenson Posted May 26, 2019 Popular Post Share Posted May 26, 2019 On 5/25/2019 at 1:09 PM, incus said: One thing I can report back so far is that my unit decidedly did not like the LPS 1.2 as a power supply. The 1.2 was searing hot and the LED stayed red on the back of the oRendu no matter what I tried - and this is without any vBus requirements... What were you using as the feeder supply for the LPS-1.2? What you are describing is what happens when the feeder supply cannot supply enough power to the LPS-1.2. If you are NOT using the supplied Uptone Audio branded SMPS give that a try and see if that fixes the problem. John S. RC32 and Jud 2 Link to comment
JohnSwenson Posted May 28, 2019 Share Posted May 28, 2019 15 minutes ago, incus said: I am currently using and have only ever used the supplied Uptone branded SMPS with the 1.2. The 1.2 has successfully been powering other things for a while but the problem with the oRendu persists. With the LED green on the 1.2, the LED on the oRendu will start red. Then it goes amber. Then when it seems like it's about to go green it shuts down the 1.2 momentarily. Then the the 1.2 flashes red or a second. Then goes green. Then the whole process starts all over again with the oRendu going from red to amber to shutting down the 1.2 again. Any thoughts? Thanks, Aha, this sounds like the optialRendu is pulling a bit higher current right as the network connects (which is the last part of the boot process, just before it goes green) and that extra current is pushing the LPS-1.2 over the edge. It doesn't seem like anything is broken, just that probably due to manufacturing tolerances your combination of opticalRendu and LPS-1.2 just don't get along together. John S. Superdad 1 Link to comment
JohnSwenson Posted May 28, 2019 Share Posted May 28, 2019 5 minutes ago, incus said: But thank you for your explanation. What output mode are you using? Different modes might cause increased activity when connecting to the server. That might cause the bump in current. That's just my curiosity trying to figure out what is happening. It obviously doesn't work for you, so of course use what DOES work for you. John S. ssh 1 Link to comment
JohnSwenson Posted June 2, 2019 Share Posted June 2, 2019 4 hours ago, sahmen said: Okay, so the Optical module is now shipping... Will it be of any benefit if I try to use it with the ultrarendu, while waiting to get the optical rendu? And first of all, is it possible to use the optical module, along with the included fiber transceiver and the optional system optique fiber optical cable with an ultrarendu, and hear some differences? If anyone has indeed tried a similar set up, could you let us know about your experiences? I have tried this many times, it works VERY well. My experience is that It is a significant upgrade to the ultraRendu, but nowhere near as good as the opticalModule feeding an opticalRendu. John S. sahmen 1 Link to comment
JohnSwenson Posted June 3, 2019 Share Posted June 3, 2019 43 minutes ago, Foggie said: So in a scenario with a managed switch that has fiber built in - how does one evaluate/determine the performance or quality of its fiber link? With all the talk of clocks, power supplies, servers directly connected to DAC (Innuos) etc.. Confusing. SOTM has a whole line of separate devices with dedicated USB, pwr, endpoint. Specifically my switch (TP-Link TL-SG2216 ) is AC powered connected to a UPS along with my router/FW, modem, NAS, all of which are in in a network rack located in laundry room with a 25m optical cable to listening room which is connected to a FMC (Trendnet TFC-1000MGA) to a mU. Wkst running ROON server and HQP are also in laundry room connected to switch via BJC cat6e. SFP modules are cisco glc-sx-mm I'm thinking hard about next move, so many differentiating opinions about svr direct connect (to DAC) or separate modules (similar to my setup). What to do? Of course that depends on how much money you want to spend. The best sound will be from an opticalRendu and opticalModule. Plug the opticalModule into the switch with a short Ethernet cable, plug your existing optical cable into the opticalModule and the other end of the fiber cable into the opticalRendu. If you don't want to spend that much the least expensive upgrade is an opticalModule in place of the existing FMC. There are various options with ultraRendus with intermediate cost. An opticalRendu connected to the existing fiber cable, without the opticalModule at the switch end, is going to sound considerably better than the microRendu with the opticalModule feeding it. I still think it will sound better than an opticalModule feeding an ultraRendu, but the best is the opticalModule feeding the opticalRendu. Lots of ways you can mix and match the parts. John S. Link to comment
Popular Post JohnSwenson Posted June 5, 2019 Popular Post Share Posted June 5, 2019 The understanding of "isolation" in digital audio has been my passion for at least 10 years. There is a LOT of misunderstanding on the subject floating around in audio circles. Here is a quick summary of my current understanding and how the current products fit in with this. There seems to be TWO independent mechanisms involved: leakage current and clock phase noise. Various amounts of these two exist in any system. Different "isolation" technologies out there address one or the other, but very rarely both at the same time. Some technologies that attenuate one actually increase the other. Thus the massively confusing information out there. Leakage current is a property of power supplies. It is the leakage of AC mains frequency (50/60 Hz) into the DC output. It is usually common mode (ie exists on BOTH the + and - wires at the same time, this makes it a bit difficult to see. There seems to be two different types, one that comes from linear supplies and is fairly easy to block, and an additional type that comes from SMPS and is MUCH harder to block. An SMPS contains BOTH types. They are BOTH line frequency. Unfortunately in our modern times where essentially all computer equipment is powered by SMPS we have to deal with this situation of both leakage types coming down cables from our computer equipment. There are many devices on the market (I have designed some of them) for both USB and Ethernet, most can deal with the type from linear supplies but only a few can deal with the type from SMPS. Optical connections (when the power supplies are completely isolated from each other) CAN completely block all forms of leakage, it is extremely effective. Optical takes care of leakage, but does not deal with the second mechanism. Clock phase noise Phase noise is a frequency measurement of "jitter", yes that term that is so completely mis-understood in audio circles that I'm not going to use it. Phase noise is a way to look at the frequency spectrum of jitter, the reason to use it is that there seems to be fairly decent correlation to sound quality. Note this has nothing to do with "pico seconds" or "femto seconds". Forget those terms, they do not directly have meaning in audio, what matters is the phase noise. Ynfortunately phase noise is shown on a graph, not a single number, so it is much harder to directly compare units. This subject is HUGE and I'm not going to go into any more detail here. Different oscillators (the infamous "clocks" that get talked about) can have radically different phase noise. The level of phase noise that is very good for digital audio is very difficult to achieve and costs money. The corollary is that the cheap clocks used in most computer equipment (including network equipment) produce phase noise that is very bad for digital audio. The important thing to understand is that ALL digital signals carry the "fingerprint" of the clock used to produce them. When a signal coming from a box with cheap clocks comes into a box (via Ethernet or USB etc) with a much better clock, the higher level of phase noise carried on the data signal can contaminate the phase noise of the "good" clock in the second box. Exactly how this happens is complicated, I've written about this in detail if you want to look it up and see what is going on. The contamination is not complete, every time the signal gets "reclocked" by a much better clock the resulting signal carries an attenuated version of the first clock layered on top of the fingerprint of the second clock. The word "reclocked" just means the signal is regenerated by a circuit fed a different clock. It may be a better or a worse clock, reclocking doesn't always make things better! As an example if you start with an Ethernet signal coming out of a cheap switch, the clock fingerprint is going to be pretty bad. If this goes into a circuit with a VERY good clock, the signal coming out contains a reduced fingerprint from the first clock layered on top of the good clock. If you feed THIS signal into another circuit with a very good clock, the fingerprint from the original clock gets reduced even further. But if you feed this signal into a box with a bad clock, you are back to a signal with a bad fingerprint. The summary is that stringing together devices with GOOD clocking can dramatically attenuate the results of an upstream bad clock. The latest devices form Sonore take on BOTH of these mechanisms that effect sound: optical for blocking leakage and multiple reclocking with very good clocks. The optical part should be obvious. A side benefit of the optical circuit is that is completely regenerates the signal with a VERY low phase noise clock, this is a one step reclocking. It attenuates effects from upstream circuits but does not completely get rid of them. This is where the opticalModule comes into play, if you put an opticalModule in the path to the opticalRendu you are adding another reclocking with VERY good clocking. The result is a very large attenuation of upstream effects. It's not completely zero, but it is close. The fact that the opticalRendu is a one stage reclocking (which leaves some effects from upstage circuits) is why changing switches etc can still make a difference. Adding an OpticalModule between the switch and opticalRendu reduces that down to vanishingly small differences. So an optical module by itself adds both leakage elimination and significant clock effects attenuation. TWO optical modules in series give you the two level reclocking . An opticalRendu still has some significant advantages over say an ultraRendu fed by a single opticalModule, the circuitry inside the opticalRendu has been improved significantly over the ultraRendu. (it uses new parts that did not exist when the ultraRendu was designed). In addition the opticalRendu has the reclocking taking place a couple millimeters away from the processor which cuts out the effects of a couple connectors, transformers and cable. The result is the opticalRendu has some significant advantages. An opticalModule feeding an ultraRendu does significantly improve it, but not as much as an opticalRendu. So you can start with an opticalModule, then when you can afford it add an opticalRendu, also fed by the opticalModule and get a BIG improvement. I hope this gives a little clarity to the situation. John S. bobfa, R1200CL, austinpop and 15 others 9 6 3 Link to comment
Popular Post JohnSwenson Posted June 5, 2019 Popular Post Share Posted June 5, 2019 6 hours ago, MagnusH said: Ok, that might well be the case. But once you add an optical transmission like fiber, that all goes away, so any clocks before the fiber won't matter as long as the data was delivered correctly. In fact, nothing before the fiber should matter at all, provided the data was delivered correctly (the FMC after the fiber will matter though). All the optical does is block leakage, it doesn't get rid of clocking issues at all (it can actually make them worse). The fact that it is optical does not automatically apply some universal quantum time scheme that mystically aligns edges perfectly, If you send in a pulse, then another that is 50ns apart, then another at 51ns, then another at 49, that difference gets preserved at the receiver, the optical does not magically force all of them to be exactly 50ns. The raw data coming out of the optical receiver goes into a chip that rebuilds the Ethernet signal using its own local clock, that is done with flip flops inside the chip, these flop flops behave just like any other flip flops, again no magic here. I was trying to avoid re-iterating what I have said before on this, but it looks like I'm going to have to do it anyway. So how come this reclocking with a new clock is not perfect? As edges from the input stream go into a circuit each and every one of those edges creates a current pulse on the power and ground network inside the chip and on the board. The timing of that pulse is exactly related to the timing of the input data. The timing of the input data is directly related to the jitter on the clock producing the stream. This noise on the PG network changes the threshold voltage of anything receiving data inside the chip, especially the local clock going into the chip. This means the phase noise spectrum of the data coming in gets overlayed on top of the phase noise spectrum of the local clock. It's attenuated from what it is in the source box, but it is definitely still there. THAT is how phase noise gets from one device to the next, EVEN over optical connections. If you look at this in a system containing all uniformly bad clocks, you don't particularly see this, since they are all bad to begin with. BUT when you go from a bad to a very good clock you can definitely see this contamination of the really good clock by the overlaying of the bad clock. This is really hard to directly measure because most of the effect is happening inside the flop flop chip itself. You CAN see the effect on the data coming out of the flip flop. This process happens all the way down the chain, Ethernet to USB, USB into DAC box, and inside the DAC chips themselves, finally winding up on the analog out. Wherever reclocking is happening, how strong this overlay is depends primarily on the impedance of the power and ground network, both on boards and inside chips. A lower impedance PG network produces lower clock overlay, higher PG impedance give stronger overlay. This is something that is difficult to find out about a particular chip, the impedance of the PG network is NEVER listed in the data sheets! I have somewhat of an advantage here having spent 33 years in the semiconductor industry, spending a lot of time designing PG networks in chips, I have some insight into which chips look like good candidates for low impedance PG networks. On a side note, because Ethernet and USB are packet systems the receiving circuit CAN use a completely separate clock, the frequency just has to be close enough to handle the small number of bits in the packet. If it is a little to slow or too fast the difference is made up in the dead time between packets. To reiterate none of this has ANYTHING to do with accurately reading bits, this is assumed. It IS all about high jitter on network clocks working its way down through reclockings to the DAC chips and hence to audio outs. All the work done on DACs in recent years has cleaned up the signals so dramatically that these effects are getting to be audible in many systems. John S. bunno77, Superdad, thyname and 7 others 2 4 4 Link to comment
JohnSwenson Posted June 8, 2019 Share Posted June 8, 2019 1 hour ago, sahmen said: This is probably a dumb question, but I saw it coming from more than a mile away... For those using an Opticalmodule with the ultrarendu, how do you connect it (the OM) to the ultrarendu, given that the latter is not equipped with an SFP cage / SFP optical transceiver for network connection unlike the opticalRendu, which is? The RJ45 connector on my OM is receiving the signal directly from my router with my existing regular ethernet cable, leaving the SFP optical output as the only option for the Ultrarendu. I'm beginning to suspect that I may need a second FMC unit armed with its own transceiver to make the .connection work. If this is the case, then I have a TP-link MC220L unit with its own SFP transceiver on standby, which I can use, at least temporarily while I continue to sort the situation out. Now if this is indeed the case, then which of the two (The OM or the TP-LINK FMC unit) should be positioned immediately before the ultrarendu in the chain, in order to make the noise isolation work optimally? I am assuming that the OM should come immediately before the ultrarendu, but if I am mistaken in any of the above assumptions, kindly let me know. Nothing is connected as yet, since I am awaiting responses and any possible corrective input from this forum before I proceed, but here is the chain I am envisaging: Router==>Existing cable Ethernet==>>TP Link MC220L/SFP Tranceiver==>> New Optical Ethernet ==>>OM/SFP Transceiver ==>> New Cable Ethernet==>>Ultrarendu. Any helpful suggestions/corrections are wholeheartedly welcome. Thanks. Yes, your diagram is correct. Two things you need to be sure of: the two SFP modules are compatible, the optical cable is compatible with the modules and the upstream FMC is gigabit. If you want to use the SFP module that comes from Sonore the other one must match: 850nm; multimode fiber, LC connector The fiber cable must match the above. Just make sure both SFP modules match this and the cable also matches the above and you should be fine. John S. sahmen 1 Link to comment
JohnSwenson Posted June 8, 2019 Share Posted June 8, 2019 3 hours ago, sgr said: Reposted as I wanted to add more info and was not allowed. Hi, Have ORendu installed with the Sonore kit of optical cable, power supply for ORendu and an LPS1.2 powering the optical module. All components have powered up correctly and are stable. First observations the ORendu has a clarity that I’d not experienced with the URendu. I believe it does sound better and has sure improved the longer its been electrified. But...... I can only get it to work with ROON. Not as HqPlayer NAA. I’ve tried many different filters (probably not every possible combination as that would be impossible I think) and am using Legacy Audio Wavelet DAC for PCM only and can’t get it to play without stuttering or playing at all. Music will play a second or two then stop start again. I’ve rebooted the pc many times, used the sonic orbiter app to select HQPlayer Naa, done the same with ROON. Hqplayer is connected to the ORendu and sees it as a device as it did see URendu. Nothing seems to work. The URendu is unplugged and not in the system at all so I know it’s not interfering. I also did ipconfig and reconfigured the ORendu in ROON just in case and it used the same address as the URendu did so that didn’t matter. My Ultra Rendu worked fine with exact same equipment and the same settings in HQPlayer 4.4 but they won’t work on ORendu. I’d be glad for some help or ideas. Given that Roon works it is probably not a bad connection issue. Dropouts etc could be happening because of the extra two devices the packets are going through, that's about the only thing that can be different from the uR setup. How many network devices do you have between the computer running HQP and the oM? If the HQP computer is connected to the same switch as the oM, one thing to try is to temporarily put it on the same switch and see if that makes any difference. I don't use HQP so I can't give any specific advice on that, I can just ask some general questions. Is there any options in HQP having to do with buffer size or number of buffers? If yes that is good place to start. John S. Link to comment
Popular Post JohnSwenson Posted July 5, 2019 Popular Post Share Posted July 5, 2019 19 hours ago, rickca said: @JohnSwenson you made a number of enhancements to the opticalRendu (vs the ultraRendu) beyond just optical networking. Naturally, the whole optical thing has been the focus of much of the discussion because many of us have never used it before. How much of the improved sound quality of an opticalRendu vs ultraRendu is attributable to those enhancements unrelated to optical input? The optical by itself means NO leakage current gets through to the Ethernet PHY, this is significant. There is another significant side effect of the optical circuit which is a "reclocking" of the data right next to the Ethernet PHY, it is not because it is optical, but because the reclocking is done by a very good chip and it is close to the PHY. Those two together account for maybe something like 80% of the improvement. Other things are a clock distribution system that uses incredibly low phase noise buffers, and an improved power network which has lower noise and significantly lower impedance over a broad frequency range. The regulator feeding the VBUS pin on the USB jack is much better than before, so if you are using a buss powered DAC, or even one that uses VBUS for its input circuitry, that will also make an improvement. John S. soares, rickca, Albrecht and 3 others 3 3 Link to comment
Popular Post JohnSwenson Posted August 15, 2019 Popular Post Share Posted August 15, 2019 4 hours ago, Kingkoopa said: I have a switch with existing sfp outputs that are compatible with the opticalrendu. Is it recommended to use the switch’s sfp ports or to preference using the optics’s module with linear psu for the Ethernet to optical conversion instead? i have a concern around adding in the extra box unnecessarily. this is an audio quality not cost question. thanks switch is the net gear xs708t Please read post #658 https://audiophilestyle.com/forums/topic/55217-sonore-opticalrendu/?do=findComment&comment=963599 This goes into some detail on what is happening here. For your specific question, an opticalModule plugged into an RJ-45 jack of the switch is probably going to produce lower phase noise coming out its SFP port than the SFP port of the switch. The result is that using the opticalModule to the opticalRendu is probably going to sound significantly better then the SFP port of the switch going into the opticalRendu. John S. barrows and Kingkoopa 2 Link to comment
JohnSwenson Posted September 2, 2019 Share Posted September 2, 2019 9 hours ago, dminches said: Just to confirm, you are recommending a chain of Ethernet -> opticalModule -> opticalRendu? Yes that is correct. John S. dminches 1 Link to comment
Popular Post JohnSwenson Posted May 21, 2020 Popular Post Share Posted May 21, 2020 5 hours ago, R1200CL said: Jesus or @JohnSwenson Can you explain why 9VDC is not recommended for the opticalrendu ? I think I even read somewhere John stated that you may even get a sonic benefit by using 9V instead of 6 or 7V I do understand that the uR probably gets hotter at 9V and that the voltages regulators only works a bit harder to “burn off” unnecessary energy in order to reduce the internal voltage needed, but what’s the technical problem with that. (That people feel or don’t like hot items, is not a technical explanation, but of cause a valid reason those who believe that lower temperatures is good). I personally prefer 9V. There is an interesting trade off here, hotter parts can can generate less noise, but hotter parts can have a higher probability of failing over time. The semiconductor parts used today generate noise when they switch, the faster they switch the more noise they generate. They run slower the hotter they are. BUT the slower they switch the more jitter they have so there is an "optimal" point where the noise and jitter are at their lowest. I can't tell you what this point is, due to manufacturing tolerances, it varies a lot from chip to chip. There is a BIG impact on longevity produced from turning things on and off, every time you turn a device on and off things expand and contract. Over time this can cause solder joints to fail. The hotter things are the more they expand and contract each time they are turned on and off. So if you turn the device on and off every time you listen, you should probably opt for a cooler temperature if you want the device to last a long time. If you leave it on all the time you can run it hotter and still have good longevity. At the temperatures we are talking about the parts themselves will last a very long time, it's the solder joints that usually cause failure. John S. R1200CL and Superdad 2 Link to comment
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