Popular Post JohnSwenson Posted February 26, 2018 Popular Post Share Posted February 26, 2018 On 2/25/2018 at 7:08 PM, agladstone said: if you find any similar devices on Amazon that would also work, please post a link to them on Amazon for us. Particularly one of the models that comes in a small enclosure vs the bare open back on the Baylite would be preferred (there are a bunch that are enclosed on Amazon, I just don’t know which one of them will work. also, several of the enclosed models show Volts, Amperage, and power/ watt consumption simultaneously, if any of those would work, that would be really cool!! ) thanks!! @austinpop This one: https://www.amazon.com/DROK-Voltmeter-Waterproof-Consumption-Detector/dp/B015R3PMFC/ref=sr_1_45?ie=UTF8&qid=1519631375&sr=8-45&keywords=digital+panel+meter Should work. You will still probably need to solder the wires to a 3 pin header. Specs for what will work: a) Must be DC, some of the meters are for AC, they will not work. b) Must be three wire, 2 wire ones will NOT work. Most of the ones that will work have two voltage specifications, the power supply and the measured signal. The supply voltage on the LPS-1.2 connector is the same as the output voltage, 5,7,9,12. So anything that covers this range will work. A common spec is 5-30V for the supply voltage, this will work fine. A few say 3-30V, this will also work. The signal voltage range should be 0-30. If the meter says 0-100 it will most likely not have enough digits of resolution. The 0-30 ones almost all have enough resolution. The ones that show voltage and current will usually not work. They are designed to measure the voltage and current from a car or motorcycle battery. They run the hundreds of amps THROUGH the meter to test it. The current measuring capability of the LPS-1.2 is done completely differently, the three pin jack provides a VOLTAGE, which directly represents the current on the output, so the meter is measuring VOLTAGE, not actually measuring current. So a real ammeter will not work. The voltage on the three pin connector directly represents output current: 1V = 1A, 0.5V = 0.5A, 0.1V = 0.1A etc. The accuracy of the current to voltage conversion is not high accuracy, it will get you in the ballpark but don't expect the voltage to be accurate to a milli-amp. It is probably somewhere in the +-5% range. Thus if you are actually pulling 1A, the voltage might be 0.97 or 1.05 etc. You then have to deal with the accuracy of the meter itself, which for the cheap ones is not so great. The one linked above is specified as a high accuracy meter, but I have NOT tried it myself, so who knows. On top of the above you also have to deal with the current the meter itself draws, the circuit and those light emitting numbers have to be powered from somewhere, if you power it from the LPS-1.2 connector the meter will add about 20mA to the current draw from the supply. Thus if the meter says 0.10V the load connected to the barrel jack is only pulling 80mA since the meter is pulling 20mA. I hope this helps. John S. agladstone and auricgoldfinger 1 1 Link to comment
JohnSwenson Posted February 27, 2018 Share Posted February 27, 2018 4 hours ago, auricgoldfinger said: @Superdad and @JohnSwenson I always felt only lukewarm about the LPS-1, but the LPS-1.2 is an entirely different animal. I know you thought very carefully about the name, but perhaps LPS-2.0 would more accurately reflect the magnitude of the improvement that I am hearing. You guys really hit a home run with this product! Thanks for all of your effort. The 1.2 is in relation to the fact that the maximum voltage is now 12V. John S. agladstone 1 Link to comment
Popular Post JohnSwenson Posted March 3, 2018 Popular Post Share Posted March 3, 2018 The LPS-1.2 is a little less efficient than the LPS-1. there are two reasons for this: 1) The higher voltages run the switching transistors in a different place in their transfer curves which requires more drive current. This generates more heat in the driver transistors and resistors. There was no way to change this depending on the voltage. So even at 7V there is more heat generated. 2) There are two more ultracaps on the board. The ultracaps themselves generate a large part of the total heat. The current flowing through the these caps generates heat, we have two more, so there is more heat. The result is that it WILL generate more heat for a given load than the LPS-1, thus higher temperatures. In my setup powering an ultraRendu it gets a little warmer, certainly not to the point of not being able to touch it. If you are concerned about this, the best way to deal with it is get it vertical, either on its side or on the end. The front panel is flat so so you CAN set it on its front panel with the wires coming out of the "top", this will help a lot. Putting it on its side is the best, it gives the best airflow over both sides. An important thing to realize is that when it is flat (on its feet), the heat from the ultracaps can't easily get to the case to get dissipated, putting it on its side lets this heat rise to the case, this significantly cools the ultracaps. Some people have left it flat and put a heatsink on the top. This helps, but you still have the problem of not fully cooling the ultracaps. Putting it on its side, with or without a heatsink is the best way to go. John S. auricgoldfinger, johndoe21ro, asdf1000 and 2 others 4 1 Link to comment
JohnSwenson Posted March 3, 2018 Share Posted March 3, 2018 There are three error indicators--after starting up and being green: Steady red (not flashing): feeder supply voltage is too low, when this happens the LPS-1.2 shuts down and has to be power cycled to work again. Flashing red several times then green, then flashing reds again: over current, when the load current gets just above 1.1A it enters this mode. It shuts the output off for several seconds, (the flashing red), turns the output back on (green) and checks the current, if it is within spec it continues on in green. If the current is still over 1.1A it shuts the output off and flashes red... Flashing red continuously, (no green), the output has gone overvoltage (the threshold is 0.5V above the nominal voltage), it does this to protect your devices. THIS SHOULD NEVER HAPPEN. Something is wrong with your unit, please get in touch with Alex and get a replacement. I want to tear this one apart and find out what is going on. John S. Link to comment
JohnSwenson Posted March 3, 2018 Share Posted March 3, 2018 3 hours ago, tboooe said: I am planning to buy 2 LPS-1.2 units and was wondering if a single SMPS that comes with it can power them? No, the LPS-1.2 takes just less than 36W maximum from its feeder supply. The supply that comes with the LPS-1.2 is a 36W supply, it can nicely handle 1 LPS-1.2 and that is IT. So no way can you feed two LPS-1.2 from one UASMPS (UptoneAudioSMPS) John S. Link to comment
Popular Post JohnSwenson Posted March 4, 2018 Popular Post Share Posted March 4, 2018 I have done studies with a thermal probe inside the case, both in free air and touching the components. At equilibrium, the air temperature inside the case is almost the same as the case temperature so air temperature is known. For the tests that Alex did, that means the air temperature in the case is 30C or so above the ambient. But the temperature from the probe touching various components is much lower than 30C higher than they are out of the case. I'm not sure why, probably some form of airflow getting setup inside the case that doesn't happen in free air. I have no way of testing that, for a LOT of money its possible to get airflow imaging systems, but I don't know of any that I can put inside the closed case. As to the ultracap longevity, of COURSE I have looked into this!! The longevity equations depend on several different parameters, not just temperature, the voltage plays a very significant part as does the number of charge/discharge cycles, and how much of the voltage is discharged with each cycle. Remember that the voltage on the caps is NOT constant, it charges up, discharges etc, so the average voltage per cap is significantly lower than the peak value. Putting all this together with the temperature of the caps inside the closed case comes up with somewhere around 10 years to a 20% decrease in cap value. If you are worried about this, put the case on its side which will cool the case off considerably, thus lower air temperature inside. John S. gstew, R1200CL, feelingears and 3 others 4 2 Link to comment
JohnSwenson Posted April 29, 2018 Share Posted April 29, 2018 The LPS-1.2 uses a regulator that takes a fairly long time to ramp up its output voltage, significantly longer than the regulator in the LPS-1. The regulator circuit in the microRendu does not seem to like this slow ramp and will not turn on. There are two ways to deal with this: have the microRendu unplugged from the LPS-1.2, power it up, THEN plug the cable into the microRendu. Use some sort of switch on the output of the LPS-1.2 that waits until the output voltage is already close to max before turning on. This can be a relay or a transistor circuit. The ultraRendu does NOT have this problem, it is just the microRendu. John S. Link to comment
JohnSwenson Posted April 30, 2018 Share Posted April 30, 2018 13 hours ago, pl_svn said: Chord Qutest has no issue with this but... booting the LPS 1.2 will take a veeery long time if it's already plugged to it so when (almost never) I have to turn the DAC or the LPS off I unplug it, wait 'til it has completely finished bootig (led becomes steady green) then plug it to the Qutest no harm whatsoever to any of the two if one doesn't, though The LPS devices (both 1 and 1.2) have to discharge the capacitor banks before they can boot up again (the exact reason why is long and complex, I can share if people REALLY want to know, but I warned you). The amount of energy stored in a capacitor depends on the voltage, so since the 1.2 can got to a much higher voltage, it can store a lot more energy. This means it takes a LOT longer to discharge. So if you have been using an LPS-1.2, particularly if you are using 9 or 12V output, turn it off (either with the switch or unplugging the feeder supply), let the LED go black, then turn it back on, it can take several minutes while the banks are discharging before it can start charging again. When you turn on the LPS-1.2, the LED initially goes to red and stays red while it is discharging, then goes to amber while it is doing the initial charging. If the LED stays red for a long time it is discharging the capacitor banks. If the banks are discharged, which happens if you leave it off for a long time, the red lasts for a very small fraction of a second and goes immediately to amber. So the time in red (discharge) can range from a fraction of a second to several minutes depending on how much charge was left in the caps when you turn it on. The charging time also varies, but in this case it is just dependent on the output voltage. It takes much longer to charge the caps for 12V than it does for 5V. The result is that setting to 12V, turning off then very soon turning back on is the worst case, it takes a long time to discharge the banks, then another long time to charge them up again. At 5V the process is MUCH faster. John S. beautiful music 1 Link to comment
JohnSwenson Posted April 30, 2018 Share Posted April 30, 2018 16 hours ago, mozes said: Hi John If you can elaborate a bit on this part would be great. I am facing a similar issue with my LPS-1.2 when I try to power the SOTM tX-USBexp USB card in my PC. The LPS-1.2 turns green but I hear a slight buzzing noise in the LPS-1.2 and the USB card doesn’t turn on. I have tried 3 different LPS-1.2s and still have the same issue. However, the LPS-1 works absolutely fine, so I am puzzled. Is this acoustic buzzing from the LPS-1.2 itself or over the or from the speakers. Also is it coming from the feeder supply? The LPS-1.2 can take more current from the feeder than the LPS-1, this might cause problems with the feeder you are using. What feeder are you using, is it the same for both the LPS-1 and LPS1.2? The supply Alex provides with the LPS-1.2 can supply much more current than the one supplied with the LPS-1, so if you are using the one that comes with the LPS-1.2 that should not be any problem. Can you check the output voltage on the LPS-1.2 when it is in this state, if it is not delivering the appropriate voltage and is in green, then Alex will replace it for you. Even if the feeder supply cannot handle the current the LED should be red not green. John S. Link to comment
JohnSwenson Posted April 30, 2018 Share Posted April 30, 2018 42 minutes ago, Geoff1954 said: Thanks for the suggestion. I tried it but it didn't work. I am using ZyXel powerline adaptors. They show green lights. The device is recognized when using them. But it cannot be configured when it is plugged into them. (It CAN be configured if the device is plugged directly into my router. But my router is in another room so that setup is impossible for the application I am trying to use.) There are a couple of requirements for this process to work: 1) the computer you use to connect to sonicorbiter.com must have an IP address that is on the same subnet as the IP address assigned to the microRendu. 2) the computer must be able to talk directly to the microRendu 3) there must be an external internet connection on the LAN you are using Since the initial connection to sonicorbiter.com works, and it sees the microRendu then #3 seems to work, so your problem is most likely #1 or #2. If the computer is setup to get an IP address from the router, it most likely IS already on the same subnet as the microRendu, but there are some situations where this may not happen. The most likely scenario to cause #1 or #2 is the computer and microRendu are connected o the router in different ways, for example if the microRendu is wired into the LAN and the computer is connected with WiFi. Some routers are setup to not allow a computer on WiFi to directly talk to another computer, either on WiFi or wired into the LAN. They can all talk to the internet, but not directly to each other. In addition some routers are setup so a device on a wired connection gets an IP address on a different subnet than a device on WiFi. You are going to have to do a little sleuthing on this, first check if the subnets are the same. An IP address has a form of: 192.168.1.98, in this case the subnet is the second number from the right, in this case a "1", Thus 192.168.1.25 and 192.168.1.117 are on the same subnet, but 192.168.0.35 and 192.168.1.89 are on different subnets. For the microRendu you can find the IP address from the sonicorbiter.com page, it will list the address for the microRendu. How to get it for your computer depends on the computer and its OS. If you don't know how to get it, you can search the web and find directions on how to find it. One way to test if this is in fact what is going on, is to make sure both the computer and the microRendu are both connected to the network in the same way (wired) and at the same place. Since you are talking about powerline adapters I presume you are connecting the microRendu through one of these, so try connecting the computer to the powerline adapter as well. If it only has one Ethernet jack, stick a cheap switch into it and connect both the computer and microRendu into that switch. If #1 or #2 is the problem, that SHOULD fix it. If your computer only has WiFi that will be a problem. If you have SOME computer with an Ethernet jack try using that instead, if it works, then you definitely have a #1 or #2 problem. If it is a WiFi only computer problem then you need to determine if it the computer and microRendu are on the same subnet or not. I different then you need to see if you can configure the router to use the same subnet for WiFi and wired connections, if they have the same subnet, then you need to see if the router can be configured to allow WiFi devices to talk directly to wired devices. Note that none of this is a broken microRendu in any way, it is the configuration of he network that is preventing the computer from talking to the microRendu. Most residential routers are setup so this is not a problem, but some are not. Even the ones that don't allow this out of the box CAN be setup differently so this works. So first try the tests in this post (find out what subnets the computer and the microRendu are using) and see if a wired connection on both computer and microRendu to the same switch works. This should at least point you in the right direction. John S. asdf1000 1 Link to comment
JohnSwenson Posted April 30, 2018 Share Posted April 30, 2018 1 hour ago, jdoleys said: " 3) there must be an external internet connection on the LAN you are using" This no is necessary. Sonicorbiter.com is an external website, it is NOT hosted on the internal web server. If the computer you are using to configure the microRendu does not have external internet access it cannot reach sonicorbiter.com. If you already know the IP address of the microRendu (perhaps by looking at the DHCP list in your router) you can access the internal web server and do configuration without an external internet connection, but in order to do that you have to know the IP address somehow. Sonicorbiter.com was developed as an easy way to find the IP address of your sonicorbiter based devices. John S. Link to comment
JohnSwenson Posted May 8, 2018 Share Posted May 8, 2018 8 hours ago, Geoff1954 said: Because I noticed what @kissov said above, I thought it might be helpful to interject my experience (which Alex knows about through correspondence between the two of us separately). I already owned an ISO REGEN with the original power supply that came with it. (NOT the LP -1, just the basic plug in connection that came with the ISO.) My LPS 1.2 arrived last week. It powered my microRendu that also arrived last week with good results. Then I added my ISO REGEN back into the chain, which then looked like this: microRendu > ISO REGEN > Meridian Explorer 2 DAC, all powered by a Y connection to the LPS 1.2. However that combination failed. Roon did not recognize it. For this to work with Roon I had to take the ISO REGEN out of the chain of devices. After many different attempts of various sequences of plugging things in and turning things off and on (with suggestions from Alex along the way) failed, I tried one last thing. I dropped the Y connection. I used the LPS 1.2 to power the microRendu only. I used the original ISO REGEN power connection to power the ISO. Then Roon recognized everything and I can hear music again. I would rather use the LPS 1.2 to power everything and Alex expected I'd be able to do that. But at least for now I have a work around. Hopefully Alex and John can figure out why I can't use the LPS 1.2 alone with the Y connection. So to make it work you have the original MeanWell supply powering the ISO REGEN and the LPS-1.2 powering the microRendu? Have you tried swapping them? (MeanWell on microRendu and LPS-1.2 on ISO REGEN) I HAVE run into a situation where the system has a leakage loop which causes problems, but the SMPS on the ISO REGEN provides a leakage path that prevents the leakage from going through the critical part. With the LPS-1.2 on the ISO REGEN, that path is blocked so it winds up going where you don't want it to go, To figure this one out you have to make a diagram of the system including all power connections, interconnects (analog and digital), AC wiring, LAN connections etc. With it all drawn out you can start working out leakage paths and see if this situation is happening. John S. Geoff1954 1 Link to comment
Popular Post JohnSwenson Posted May 10, 2018 Popular Post Share Posted May 10, 2018 3 hours ago, pl_svn said: yes, Alex, was about to ask yesterday: could you, please, add on your website the instructions for correctly wiring the Bayite voltmeter? thanks Very simple: black goes to "G" red goes to "V" whats left (white, yellow etc) goes to "I". John S. pl_svn and mozes 1 1 Link to comment
JohnSwenson Posted May 11, 2018 Share Posted May 11, 2018 24 minutes ago, kissov said: I'v just noticed that the light on the back of the LPS 1.2 never goes green? I've tried different power sources but no change? What am I doing wrong? Thanks. What is the sequence of color on the LED? The normal sequence when turned on is: red, anywhere from 1/10th second to 2 minutes depending on the charge on the caps. If it stays red for a while it is discharging the caps. amber, anywhere from 25 seconds to two minutes depending on the output voltage. green, output is turned on. So how does it vary from this? Remember some of these steps can take a long time. Have you tried with the UpTone branded SMPS that come with the LPS-1.2? Can you check the output voltage, if the LED never goes green, there should never be any voltage on the output. Thanks, John S. Link to comment
Popular Post JohnSwenson Posted May 14, 2018 Popular Post Share Posted May 14, 2018 On 5/13/2018 at 8:07 AM, bit01 said: Hi R1200CL, Thanks for your thoughts on this. The smsp is their new 36W Uptone Audio branded one that comes with the LPS 1.2. When I switch it out for the SR4 I do not unplug it from the power strip. I have not noticed any difference whether it is plugged in or not so its audible effect on the other components is NIL at least as far as my hearing is able to discern. I am using what I believe to be excellent custom DC cables made from aerospace Mil-spec 2x22awg silver plated OFC in near starquad (SR4,12in ->LPS-1.2, 10in ->to uR) ! Unfortunately I cannot use the same on the smps without modifying it due to its molded in cable. ATB b. When you say switch to the SR4 do you mean the SR4 is feeding the LPS-1.2 and the UA SMPS is unplugged from the LPS-1.2 and still plugged into the AC main? Then you try with the UA SMPS unplugged from the main and don't hear any difference? This is not a particularly good test since the SMPS is not connected to a load, if anything is being injected into the AC mains it is most likely going to be correlated with how much power is going through the supply, with no load there is probably very little going in the mains. To be a valid test you should have some heavy load on the SMPS. John S. johndoe21ro and R1200CL 1 1 Link to comment
JohnSwenson Posted July 1, 2018 Share Posted July 1, 2018 There is a known issue with the LPS-1.2 and the microRendu: the microRendu will not start if the DC cable from the LPS-1.2 is already connected when power is applied to the LPS-1.2. The only way to get the LPS-1.2 to power the microRendu is to power up the LPS-1.2, wait until the LED goes green, THEN plug the DC cable into the microRendu. The ultraRendu and the LPS-1.2 work fine in all ways you can connect and turn them on, it is just the microRendu and the LPS-1.2. So however you want to do it, the LPS-1.2 LED must be green BEFORE you connect the DC cable to the microRendu. The output of the LPS-1.2 takes quite awhile to ramp up (about a quarter of a second) once the LED goes green. The power circuit inside the microRendu does not like this slow ramp time. Plugging the DC cable in gives a MUCH faster ramp time (a couple milli-seconds) which the microRendu is perfectly happy with. The ultraRendu has a different power circuit which doesn't care about the slow ramp time. Just to be clear it doesn't which matter which end of the power cable is plugged an after the grreen light, you can have: 1) the DC cable not plugged in at all, then after the light is green plug the cable into both LPS-1 and minroRendu 2) The DC cable plugged into the LPS-1.2 but not the microRendu, after the green light plug the DC cable into the microRendu 3) The DC cable plugged into the microRendu but not the LPS-1.2, after the green light plug the DC cable into the LPS-1.2 John S. gstew 1 Link to comment
JohnSwenson Posted July 16, 2018 Share Posted July 16, 2018 51 minutes ago, azupan75 said: I succesfully used lps-1 to power multiple units. Not so with lps -1.2. I tried and had to replace the unit due to failure. Yet won’t experiment multiple powering again with the replacement unit. Lps-1 I fully trust, with lps -1.2 I’m staying on the safe side. Just my experience. With others may differ. There is a known issue with the LPS-1.2 and the microRendu. If the DC cable between the microRendu and the LPS-1.2 is already connected on both sides and then you turn on the LPS-1.2 the microRendu will not power up. If powering a microRendu from an LPS-1.2 you need to power up the LPS-1.2 first (wait until the LED is green), THEN connect the DC cable to the microRendu. This just happenes with this particular combination, the UltraRendu doesn't have the problem and an LPS-1 doesn't have this problem with the microRendu. The issue is caused by the LT3045s used on the output of the LPS-1.2, they have a long turn on ramp time (about 1/3 of a second), the microRendu does not like this. The LPS-1 has a shorter ramp time (1/10 of a second) which doesn't seem to cause the problem. The UltraRendu has a different internal power network which doesn't mind the slow turn on ramp of the LPS-1.2. I have used the LPS-1.2 extensively powering multiple devices in parallel it works fine, as long as the above issue with the microRendu is taken into account. SO there is not an "inherent" issue with driving multiple loads. Of course the total load has to fit within the 1.1A capability of the LPS-1.2 (same as the LPS-1) and many devices take more current at startup so that can sometimes cause issues, but that is the same for the LPS-1. There ARE small differences from unit to unit, (for both LPS-1 and LPS-1.2) so some units might be able to handle 1.18A and other "only" 1.12A so it is possible to have a total startup load that falls in this range and your LPS-1 is a unit that can handle 1.18A and the LPS-1.2 can handle 1.12A, and thus your LPS-1 can handle that particular combination load and your LPS-1.2 cannot, but that is not general issue with "the LPS-1.2 cannot handle multiple loads", just the normal manufacturing spread of units. If you have a situation where an LPS-1 can handle a certain set of multiple loads and the LPS-1.2 cannot, it is most likely one of these two scenarios. John S. Link to comment
JohnSwenson Posted July 16, 2018 Share Posted July 16, 2018 1 minute ago, sahmen said: John: This is very informative and helpful, but I have one related question. Should one expect Sound quality to take a hit (i.e. be compromised in any way), when one LPS-1 is used to power two components in this way (in my case, a microrendu and an Iso-regen), as opposed to using 2 LPS-1 units, with one dedicated to each component? Whenever you have a single supply powering two loads you can have a situation where changes in load current from one device cause a small change in voltage on the supply output, and those voltage changes are seen by both devices powered by the supply. So yes it is always possible powering each device with its own supply might sound better than both off the same supply, but the LPS-1.2 has an extremely low output impedance, so any voltage change due to load current changes are going to be VERY small. Thus the LPS-1.2 is probably one of the best supplies out there for powering multiple loads (as long as the combination doesn't go over 1.1A) There is a special issue with the ISO REGEN. It contains an isolation circuit whose purpose in life is to prevent leakage current from traveling through a USB cable. If you power the ISO REGEN and the upstream device from the same power supply you are bypassing this isolation. This may or may not be an issue depending on what is driving the ISO REGEN and how things in your system are connected. It is hard to make a determination without knowing the details of the system. Note: the isolation is not the ONLY reason for an ISO REGEN, even with the isolation bypassed it can still significantly improve your USB signal. John S. Link to comment
JohnSwenson Posted July 17, 2018 Share Posted July 17, 2018 8 hours ago, lmitche said: Hi John, For the avoidance of doubt, in this context does upstream device mean the device connected to the female Usb B input side of the ISO Regen? Thanks, Larry yes. John S. Link to comment
JohnSwenson Posted July 17, 2018 Share Posted July 17, 2018 5 hours ago, tims said: Hi John If you are powering both the ISO REGEN and an upstream device (as discussed above using a single LPS-1.2) but this time have (for instance) two ldovr LT3045 regs (http://www.ldovr.com/product-p/lt3045-m.htm) after the LPS-1.2 (with the LPS-1.2 feeding both ldovr regs). Would this setup now provide the necessary isolation to prevent leakage currents as the ISO REGEN and the other device now have their own separate ldovr power supplies or doesn't it work like this? Thanks No, adding regulators does not block leakage current. The leakage current usually travels through the negative connection ("ground"), two regulators connected to the same supply have have their negative inputs connected together and to the single supply output, thus leakage current is free to flow through all of them. A separate LT3045 on each branch WILL isolate noise created by the changing load current from one load showing up on the other, but it will not block leakage current. John S. Link to comment
JohnSwenson Posted October 31, 2018 Share Posted October 31, 2018 I can't prove it yet (I'm working on it) but there seems to be two primary sound impactors from the network side: high impedance leakage from SMPS attached to network equipment, AND the phase noise of the clock that clocks out the data bits on the line. The optical interface completely blocks any leakage coming from upstream network devices, but it ADDS the phase noise of the clock in your FMC. It is certainly possible that this extra phase noise has a higher impact on sound than the decrease leakage the optical brings. BTW the difference in "picking up" noise between a copper cable and the optical is quite small. John S. Link to comment
JohnSwenson Posted November 3, 2018 Share Posted November 3, 2018 43 minutes ago, agladstone said: John: So, without the Optical FMC in the chain (as discussed above), would the “phase noise of the clock “ then be coming from the router (or switch) ? Would an in-line Ethernet isolator have any impact on improving the phase noise of the clock from a router or switch? Note that I do NOT have detailed explanations of everything right now, this is conjecture based on preliminary findings, there is a LOT more research to do before I can really say what is happening. What I am going to be mentioning is what seems to be happening, NOT detailed explanations of mechanisms at this point, I can't give those yet. All oscillators, some much more than others have what is called phase noise, this is a different way of looking at jitter, which seems to have a higher correlation with sound than traditional jitter numbers. The oscillators in inexpensive equipment (such as inexpensive network gear normally used in homes) are usually on the very large phase noise side of things. The data coming over any digital stream (Ethernet, USB, whether copper or optical) is clocked out of the source component by the oscillator in that component, thus the phase noise of the oscillator gets "baked in" to the data stream, the arrival time of the data edges varies slightly, ie jitter which is determined by the output clock. When that data goes into another device, some how some of that noise winds up adding to the phase noise of the local oscillator in that component. As I mentioned the exact mechanism for this is not known, I'm working on it. So even if you have a very low phase noise local oscillator it can get swamped by what is coming in from upstream sources. This adding of upstream noise to the local clock seems to vary from device to device. I have no idea what causes the difference, that is one of the things I'm trying to figure out. The passive Ethernet isolators are just transformers and have no impact on any clocking issues. They have a slight impact on leakage currents. So the phase noise that make up this additive upstream noise can come from a router, a switch, and other devices plugged into the switch. In a normal "home network" it can be coming from all kinds of things, adding together in various amounts. I can't give any definitive rules at this point, I don't know what the mechanisms are yet, so all anybody can do right now is try different things. One thing to be careful about is coming up with your own theories and making large buying decisions based on those theories. There is a high probability any theories that are come up with right now will be wrong, that's just the way these things go. In a couple years things should be different. But for now it is the wild west. John S. Link to comment
Popular Post JohnSwenson Posted November 23, 2018 Popular Post Share Posted November 23, 2018 The LPS-1.2 already has two LT3045 regulators in parallel. It is theoretically possible to use the same techniques to parallel 2 boxes together, BUT that is a different design. It takes a different board and several connections between boxes, it is NOT trivial. The existing LPS-1.2 design is VERY carefully tuned, doing anything to the design is guaranteed to break SOMETHING, it would take several prototypes and months of development work to get right. I do NOT want to do that. I want to focus on the new developments we are working on now, any modifications to existing designs are just going to slow down the new developments and I really don't want to do that. John S. lmitche and gstew 1 1 Link to comment
JohnSwenson Posted December 23, 2018 Share Posted December 23, 2018 The heat from the supply is dependent on the output current, irrespective of the output voltage. So 1A at 5V the heat is the same as 1A at 12V. So lower output current, it's cooler, higher output current, it's warmer. John S. rodrigaj 1 Link to comment
JohnSwenson Posted January 12, 2019 Share Posted January 12, 2019 5 hours ago, tboooe said: @Superdad question regarding the charging supply for the LPS-1.2. I understand there is a strict requirement for 36W. Right now, i am powering both an LPS-1 and LPS-1.2 from a single 9V output from my HDPlex 400W DC ATX power supply. According to the HDPlex website the 9V output is only capable of 3A or 27W total, so assuming that spec is accurate I have a few questions: Is it possible for the LPS-1.2 to be powered at this lower wattage? I assume I able to because I am powering my 5V SU-1 with it. Is this correct? If so, is there any potential to damage the LPS-1.2 by powering it at this lower wattage? Is the 36W requirements only if we are using the LPS-1.2 to power something at 9 or 12V? Here is what is actually going on inside: the ultracaps are charged at two rates, the high current mode is roughly twice the current of the low current mode. The change between modes is determined by the output current, with a threshold of 0.5A. Above 0.5A the high current mode is used, below,, the low current mode. There is also a fixed current overhead that powers all the control systems, sensors, ADCs, opto isolators etc. The overhead is constant, so "low current mode" is a bit more than half of what high current mode takes. For a particular charging mode the current to the ultracaps is constant, BUT the voltage it charges to is higher for the higher output voltages. The caps are charged to 5V higher than the output voltage. Thus the power required to charge the caps increases as you go to higher output voltages. Thus the highest input POWER happens when in high current charge mode, and 12V, output. At lower output voltages the maximum input power is lower but it is NOT in strict relationship of output voltages. Remember the charging is 5V above the output voltage, the fixed overhead and the fact that the charging current actually increases at lower output voltages. There are fixed voltage drops in the charge circuit, at the lower voltages these become a larger percentage of the whole voltage budget, thus the current has to be increased to cover these fixed losses. Its all quite complicated, but we take care of all that. THEN once you have the input POWER requirement you get to compute the input current needed for a particular input voltage. But the conversion is not perfectly efficient, there ARE some losses there. The result is that yes the input current requirement decreases for lower output voltage, and for output current below 0.5A, but there is no easy way to calculate exactly what it is. Its not even easy to measure, the input current is not constant, charging happens for a period of time, then turns off while the other bank is discharging. In addition the current changes during a charge time. When charging is happening the charge current is constant, but the voltage increases, thus the power during a particular charge time is increasing. If you look at the input current on a scope you will see a saw tooth because of this. The peak of that saw tooth is the important part, that is the peak current required by the input supply. To actually measure it you need a peak hold current meter or a scope. So yes, the input current requirement IS lower for lower output voltage, but don't even try and figure out what that might be. The 36W covers everything so we recommend using that. A 27W or 25W supply MAY work for a particular load and output voltage, but there is no way to calculate that in advance. You can certainly try something lower if you want to, but it may not work, there is no way we can guarantee anything below the 36W. We know 36W works for the maximum the LPS-1.2 can output, for anything else it's up to you to test it out. On a note to Alex's post above, the LPS-1.2 has a much higher maximum input voltage than the LPS-1, it is rated for 24V input. John S. Superdad 1 Link to comment
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