Maybe not over 1 or 2 days testing in the lab, but over the lifetime of the PSU I would be very concerned by the poor thermal performance. They have managed to combine poor cooling with a noisy fan, the worst of both worlds!

I've had the chance to try the Tagan U01, U15 and U22. I liked the old U01 series Tagan PSUs. They were the only ones from Tagan that I consider quiet. The U15 and U22 are noisier than the U01 series.

Edited: some grammar (sorry for my poor English) and 2force=U22

Tagans are very popular among PC enthusiast in Poland and I've personally longed for a review of one by SPCR. A lot of people around here, and I mean pros, would swear Tagans to be among the best in terms of noise - or quietness. On the other hand, lots of folks claim Tagans are indeed noisy. I guess this can be explained by the multitude of various models. It would be great to see other Tagan PSUs tested by SPCR.

I've personally heard 2 or 3 Tagans and Topowers (in similar configurations and conditions) and must say Topowers bahaved much better - in terms of noise. I know it's not a proper way to compare PSUs but that can reflect the state of things.

One more wish, if I may, how about Topower? Are these also going to be tested? I'm asking about that because thery're also very popular round here and enjoy high esteem. And also because Topower & Tagan are in fact the same design and share a lot.

Agreed. But they also tend to run as hot as hell.

BTW U22 = 2Force

I wonder if this PSU suffers from the same design flaw as the Tagan TurboJet 1100W

http://www.hardwaresecrets.com/article/403/1

Read this review. It also uses two transformers, but they use the same transistors to drive them!

True, my fault

U01 = black series (2 80mm fans, push/pull)
U15 = easycon series (1 120mm fan)
U22 = 2force series (2 80mm fans, push/pull but noisier)

There was some samples with problems, but Tagan corrected the flaw(s).
kater I'll quote from a respectable member:

I was considering an U22 but their lack of customer support (not answering emails) made me go NeoHE. I'm very happy for that now

Interesting about the temps at full load - doesn't inspire my confidence much this unit will hold up well over time.

Out of curiosity, did anyone get a good look at what brand the capacitors on the secondary side are? The ripple oscillogram looks a bit wierd to me.

We've reviewed quite a few Topower models in the past, but never under Topower's own brand. As a general rule, they are very quiet, and very, very hot.

Topower reviews we've done include BeQuiet!, Mushkin (this one's really bad), ePower, Raidmax, OCZ, and others.

There's no any connection between dual transformer design and voltage stability. Tagan/Topower has independent voltage stabilization with an additional mag-amp on +5V rail.

I would disagree. Splitting a load across two sources should mean that the output range handled by each transformer is smaller than it would be if there was only a single transformer. Since voltage regulation is nearly always tied to changes in load, smaller changes in load should lead to smaller fluctuation.

That said, I was unaware of the additional regulation circuitry in the Tagan. I will change the wording so I don't imply so much.

I would not say Topowers are "generally" very, very hot. Some are, some are not. Temp rise in the Be quiet was 8°c at 430W, compared to 12°c at 400W in the S12 E+. A 4°c difference, or 50% if you prefer. And the seasonic was louder at 400W than the BeQuiet was at 430W. Which makes the Topower both cooler and quieter than the seasonic at high loads.

It doesn't matter what the loading is, it only matters that PWM circuit should have enough duty cycle reserve under that loading.

The reason why most ATX PSUs have unstable (+-5%) voltages is that they have multiple outputs and only one PWM stabilizer which tries to keep balance between outputs.

The reason why this PSU has two transformers... I don't know for sure, but it seems possible that they use old schematics, something like half-bridge converter. Half-bridge converters require bigger transformers than modern topologies like double forward converters, but with 120 mm fan there's no room for such a big transformers. Other manufacturers (Seasonic, FSP) use double forward converters, higher frequencies and smaller transformers, Topower decided to split one transformer in two.

That seems plausible to me... from what I've seen of Topower, the designs do seem a bit dated.

They are different. Look closely at the socket and the arrangement of circular and square plastic pins is different. Therefore making it impossible to plug in a blue cable to a black socket and visa versa