TeraDak Linear ATX PSU: SMPSs suck.

[GUTB]

I've recently installed the TeraDak 380W PSU with ATX connectors in my dedicated audio PC. The PSU came with hard-soldered 12V motherboard connector (4-pin, you don't need to use 8-pins), the main 24-pin connector (DC-DC converter board) and a 5V connector for hard drives. My SSD is externally powered via a USB-to-SATA splitter cable so the 5V connector is unused. There is also a Molex connector that seems wired up for 5V to a USB card, but my PPA OCXO card is externally powered via a USB charger battery pack. It also comes with a harness for various female connectors which I have no idea what they're for -- one of them looks like a fan connector?

 

The unit powers up immediately, no warm up period is needed. It does emit a soft but audible hum. The Seasonic Platinum passive PSU it replaced was virtually silent. My audio PC:

 

ATX motherboard, i7-7700K + passive heatsink (giant NoFan radiator rated for 95W).

16GB of RAM, dual channel.

PPA OCXO USB controller on first PCI-E slot (no video card present), external power variant.

SSD + USB-to-SATA splitter cable.

Windows 10 + Fidelizer Pro (Purist profile) + Roon + HQPlayer.

 

Playback chain:

Audio PC (PPA OCXO) -> USB -> LKS USB-100 -> HDMI -> Gustard X20U -> Schiit Freya -> Linndenburg Allegro -> Fritz Carbon 7 SEs.

* USB-100 and PPA card are sharing the battery pack for 5V power.

 

The Seasonic Platinum was selected for its low ripple characteristics and fanless design. The USB line providing 5V power to the SSD is run into another room via USB extension cable and plugged into a simply USB charger; this was done to eliminate the SSD power noise from the audio circuit altogether.

 

Without any burn-in period, it's evident right off the bat that audio quality has been improved. It appears to have stripped away that last layer of noise / distortion / haze / mud that kept complex musical passages from clearly defining individual instrument notes. When listening to simple acoustic and small ensemble type music, the difference is much harder to discern and I wouldn't call the $530 after shipping price tag worth it -- but in orchestra and complex fast-moving pieces, the extra definition to notes is obvious. A/B testing is tough because of the long period of time you have to spend turning off the PC, replacing PSUs, and turning it back on again -- but what I've done so far seems clear to me that the difference is significant and real.

 

I feel that my system has finally crossed over into the analog audio quality domain. Weather because of super low ripple power, or cleaning up a ground loop, or just eliminating switching noise from the audio circuit, I'm not sure. But, one thing I am sure of: switching mode power supplies are TRASH and don't belong in audio.

 

 

 

 

 

 

[ismewor]

@GUTB Congrats , and welcome to the ATX/LPS world. I really don't know why but some are still follower on SMPS and trying to fix the issue. Now is time to compare ATX/LPS quality caps design etc. Do you do up sampling on HQPlayer? and what is the temp of the ATXLPS.

Also an suggestion, on your PPA use the ATXLPS also. Batt is ok if you don't step into complex and bigger music. I feel happy for you. I switch to ATXLPS 2 years ago. and couldn't turn back for SMPS no matter what other has found a way to improve SMPS

[kilroy]

I'm wondering how the quality of this LPS compares to the HDPlex 400 watt unit in regards to having a positive affect on sound quality.

[marce]

There are still likely to be POL SMPS's on board. Also a PC generates a lot of its won noise, this is why you can get spread spectrum DDR these days.

[sandyk]

On ‎17‎/‎11‎/‎2017 at 5:21 AM, marce said:

There are still likely to be POL SMPS's on board. Also a PC generates a lot of its won noise, this is why you can get spread spectrum DDR these days.

 Marce

 What is won noise ?

 I find it very interesting that we still can't get the supposedly whiz kid  Software writers such as Speed Racer (?)  to fix the very long term problem of occasionally getting the order of letters we type out of sequence !

You almost certainly did NOT type won , you would have typed own. 

Correct ? 

[marce]

LOL I missed that one... I am terrible at typing.

[sandyk]

20 minutes ago, marce said:

LOL I missed that one... I am terrible at typing.

 

 Hi Marc

 It wouldn't have been your fault. It is a common problem, that you will often  see.

Many of them are so obvious, that you know it couldn't have been your fault !

Regards

Alex

 

 P.S.

 A friend of mine uses a 300W HDPlex. We have previously found that it benefits substantially with a JLH PSU add-on (typically  4uV,or less,  noise). after it's Adjustable Output(s) to supply Regens or USB cards. It appears that it's output noise, although not too bad, could do with further improving.

  I have been asked to make a larger current capacity JLH to feed his Uptone LPS-1 from the HDPlex adjustable output,(perhaps set to +7.5V) and we hope to trial it next Friday.

 

Alex

[marce]

I did wonder, I thought it was just bad typing... Interesting i will watch out for it.

As an aside, we have Windows 10 at work, we have noticed with a new update that sometimes when working in one window, we get interactions in a another Window... This is all on Dell M6700 laptops, so we don't know whether its machine specific or due to the operating system. What it implies is that some mouse signals via the USB are getting fed to other open but inactive windows. We have noticed other issues with USB on these devices, and they are not cheep laptops. Having worked on real-time industrial networks in the past I know how bad the Windows operating system is at even pseudo multi tasking, so I suspect some problem with the control of the various windows. Its a bit off-putting when you are working in one window and another opens on your second screen. This only seems to happen when there is rapid mouse movements. 

[kilroy]

I've had no luck with Teradak answering my emails about the cost of the TeraDak 380W PSU and shipping to the US. Could you please let me know? Am weighing that against the 400 W HDPlex unit.

[GUTB]

2 hours ago, kilroy said:

I've had no luck with Teradak answering my emails about the cost of the TeraDak 380W PSU and shipping to the US. Could you please let me know? Am weighing that against the 400 W HDPlex unit.

 

It's about $515 after shipping. I could have sworn I paid $530 though.

https://www.aliexpress.com/item/TeraDak-380W-music-computer-PC-dedicated-power-supply-Pure-copper-Ring-transformer-big-power/32820250604.html?spm=a2g0s.9042311.0.0.kMcvLQ

 

It works fine with no problems, except for a few things:

 

1. It hums, and it's loud enough to be perceptible from my listening position, although generally its drowned out by other ambient noise.

2. It's delicate. I accidentally hit the wrong switch in my listening room which turned on the ceiling fan...and caused my PC to crash.

3. Quality improvement is noticeable, but also relatively minor as compared to the fanless Seasonic Platinum. I don't know if that's because DC-DC conversion just mitigates quality gains no matter what, or if it's just because the TeraDak isn't the best, or maybe the long DC cables need shielding. I'd have to compare with others.

 

 

[marce]

So it has EMC problems both emitted and susceptibility yet its an improvement...

[GUTB]

6 hours ago, marce said:

So it has EMC problems both emitted and susceptibility yet its an improvement...

 

The improvement is real. I had to test it back to back with the Seasonic to be sure. The improvement is hard to tell with pristine acoustic and jazz type recordings where the notes aren’t competing for the frequency space, but with complex tracks there was a increase in note separation and overall clarity. There’s probably an ultrasonic noise component to the subjective experience as well...but obviously that’s just a guess.

 

Even though the improvement is minor compared to my other tweaks/upgrades, it was that last nudge that seemed to finally push my system over the top of the divide between digital and analog.

[kelvinwsy]

hi gutb

i am thinking of powering my z170 skylakei6700k with a teradak 380watt linear psu and to use my existing Corsair AX760 Platinum PSU just formy GeForce 970M GPU.. i an also using Elfidelity fan filter DDR4 RAM filter, OCIe filter (twin)

opinion? suggestions?