bodiebill

For my audio endpoint I made new measurements on the ATX part as I found a 19V SMPS for it. Now the comparison is more fair as I used SMPS'es for both ATX and EPS/CPU. The result is: ATX EPS/CPU maximum W A W A startup cycle 19.1 0.08 15 0.07 idle 16.7 0.07 4.5 0.02 playing music 16.9 0.07 7.4 0.03 stop cycle 17 0.07 7.8 0.03 Power draw at the ATX side (via HDPLEx 800W DC-ATX rail 1) is even lower than before when measured with the LPSU, but still higher than at the EPS side. Note that the W & A values when playing music are independent of the audio format (redbook, hi-res PCM or DSD256). On the server there is a huge difference (as I can see from the temperatures) but for the endpoint, which just streams and does not process, there seems to be no difference. These figures will save me some money 🙂

I already compared: (1) HDPlex 200W 10A 12V rail => EPS/CPU with (2) HDPlex 200W 2A LT3045 15V (variable) rail => MPAudio DLS-HPULN 5A 12V out => EPS/CPU In theory the MPAudio can supply 5A but this must be limited to the 2A of the HDPlex. 15V to 12V is a big drop. This has the advantage of lower ripple but could generate a lot of heat. Not in this case: while playing music the MPAudio hardly becomes lukewarm as the current is so low. And (2) is the clear winner: better bass, more presence and less strident highs. So in this case the 'higher quality' PS that is the result of several LT3045's wins from the powerful PS.

Just curious to know who here have tried inserting a USB device (such as ISO Regen or iFi micro iUSB3.0) between the PC and the Terminator. And whether it positively influenced SQ or not...

Thanks @austinpop ! I measured the ATX and EPS/CPU wattage drawn and the results are as follows. The AC here delivers 230V, so based on the wattage I calculated the current: amperage = wattage divided by 230. ATX EPS/CPU max values: W A W A start cycle 21.8 0.09 15 0,07 system idle 19.1 0.08 4.5 0.02 playing music 19.4 0.08 7.4 0.03 stop cycle 18.7 0.08 7.8 0.03 Pretty low maximum values overall, as measured per cycle/use. The HDPlex I am now using delivers 10A which seems overkill, so I would not hesitate to use my soon-to-come 38W/2A SR4 for either ATX or EPS, or even both. Just to find out which sounds best: the 'best' or the most powerful PS... Apparently, for this system, it is true that any PS that can successfully post and boot the PC will be more than enough to handle all running processes. Interestingly enough the EPS draws less than the ATX, so Nenon's rule "put the most powerful power supply on the CPU" may apply to a powerful server with high-TDP CPU, but not to such a minimal endpoint PC.

ah thanks, I seemed to have missed Alvin's answer... so anything lower than 5VDC will apparently not function as a logic trigger...

OK, it was worth a try. The 100 multiple that you mention for bursts may be correct for gaming servers or servers running HQPlayer with EC modulators, but will be much lower for my audio endpoint which ONLY receives an audio stream and passes it true. Actually the audio endpoint's burst multiple should be lower than approx. 6 as a 1.75V power supply could handle everything (ATX + EPS together) without a problem for more than a year.

Does it really require 5V? Or does it only use VBUS to sense a connection? I am asking as in the latter case I could power an ISO Regen with 5V (converted to 3.3V by the Regen). See:

A Brennenstuhl power meter arrived today and I did some measurements. I may need some help here as I am somewhat baffled by the first results. Please note that I only measured my minimal audio endpoint PC with AudioLinux headless (meaning GUI-less) + NAA. (I am not in a hurry to measure my heavy-lifting server as I am happy with its current power supply.) First the audio PC specs: mobo: Supermicro X11SAE-M cpu: Intel Core i3-6100T (35W TDP) memory: 2x Apacer D31.23185S.001 4GB ECC DDR4 2666MHz (wide temperature) PSU internal: HDPlex 800W DC-ATX converter NIC: Intel X520-D1 HD/SDD: none CPU / EPS I used a simple 12V SMPS: - steady state (nothing running): 0.04A - playing any kind of audio file (redbook, hi-res PCM or DSD) streamed from the HQPlayer server): 0.14A ATX I used a 19v Chinese linear PS, wattage unknown as I did not have an SMPS that fitted: - steady state: 0.17A / 30W - playing music: does not change, always at 0.17A / 30W (does not change) So maximum total current drawn approx. 0.3A. Such low amperage? It does not make much sense to me. But it is consistent with the fact that I used to power the whole PC (ATX+EPS) with a 36W / 1.75A / 19V SBooster without problem. Probably someone here can tell me what I am doing wrong?

After fabricating another short DC cable with Supra CAT8 to replace the stock HDPlex cable for the motherboard, I am now powering as follows: - HDPlex 200W 19v/10A => HDPlex 800W DC-ATX => motherboard - HDPlex 200W 12v/10A => CPU - HDPlex 200W 12v/2A (variable output) => MPAudio DLS-HPULN 10.5V/5A(2A) => USB (iFi micro iUSB3.0) => Amanero/Lampizator This is very nice sounding with great slam and dynamics, and not strident. I begin to wonder whether whether my dissatisfaction was with the HDPlex LPSU or its DC cables. With serious cables there seems to be a clear improvement! For the USB I did try with (12V => 10.5V) and without (12V) the MPAudio (which takes 9-12V), but the former is clearly better. More rest and ease! So the MPAudio stays in for now. So for now I am listening to this setup, which has the beauty that I am using one AC power cable less. In a few weeks I expect a Denafrips Terminator, which some say makes the likes of iFi micro iUSB3.0 or ISO Regen redundant...

Can this be measured if it is not mentioned in the manual/specs?

Will do. I just ordered a watt meter... In any case, the wattage required by the PC (or CPU, ATX) will be lower than the AC wattage measured, and similar for the amperage. And that is better than the other way around. And thanks for the pointers; I will try to do a thorough test.

That partly concurs with my recent experience: I hardly heard a difference powering my HQPlayer server (far away from and fiber-connected to my AL+NAA endpoint) with a nonlinear Seasonic 400W PS vs a HDPlex 200W linear PS. I have chosen for the former as it is more powerful and generates less heat. An ever so slight preference for the SQ with the Seasonic could be the result of this 🙂

Interesting questions/observation. Not that I have an immediate answer, but in the discussions above it is not always clear to me when we are talking server or endpoint, or maybe better: high-lifting PC (such as HQPlayer) or Spartan audio streamer (such as AL, Euphony, NAA). I think this makes a big difference. I do not think there is one PS-related 'truth' for both.

I see your point re inconvenience. But with an existing system (such as my audio PC) the kill-a-watt meter approach seems like a good sanity check. So I guess with the conversion loss the measured AC power will be higher than the actual DC power supplied. That means that if we calculate amperage required from the LPSU based on the AC power, we will in fact have some headroom as actually less is needed. Correct?