X750 - Internal Design

Seasonic created a very unique layout with the X-Series. Even though the basic idea is similar to other designs (e.g. Revolution85+ series) in placing both VRMs on the PCB for cable management, it is an unusual structure together with SMDs (Surface Mounted Devices). The layout looks particularly open because all the rectifiers in the secondary circuit are on the back of the plate and only small dissipaters pass through the PCB.

We can see that the X-series wants to meet high-end requirements as opposed to the Pro/Modu87+ series by looking at the line filtering stage (from Yunpen) behind the AC-inlet, which is more expensive and improved compared to using individual filtering components. With a pair of Y-capacitors and a current-compensated choke it is suitable against common mode interferences, contains above all another X-capacitor. Also a MOV was integrated into the filtering, which continues on the motherboard together with some more devices.

Taking a look at the Power Factor pre-regulator, you can see a well stabilized choke and two Nippon Chemi-Con main capacitors. Both are specified at 400V, 360 microfarads, and 105 °C. The circuit with a resonance converter and champion controller (CM6901) follows, as already mentioned. The last component is physically located behind the fan control in the bottom left corner, as you can see on the following picture.

The X750 uses many solid-state capacitors, likewise from Nippon Chemi-Con, and small upright-coiled chokes shape the look of the secondary circuit. The PS223 safety device chip from Silicon Touch provides necessary safety features like OPP. There is still no OCP, but we have never encountered any problems in practice. Current flows over a small number of cables to the DC-to-DC converter, which is equipped with an Anpec controller. The smaller +3.3V and +5V are generated there connect to the connection panel and modular cables, along with +12V.

X750 - Resonant Topology X750 - Voltage Regulation and Quality
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  • cmdrdredd - Wednesday, April 14, 2010 - link

    I use an HX1000 Corsair PSU in my system, I would have bought this unit because it's higher quality but they don't make more than 750watt units in this series. Why not?
  • 529th - Thursday, April 15, 2010 - link

    The 750 should put most machines today in the most efficient part of the efficiency curve.

    With the 650 model you hit the highest efficiency of 92.1% between 269-292; and most systems draw around there when gaming. My i7 920 (stock clocks,) 5870 (stock clocks,) 6g 1333 1.6v, was right between there; and I'm glad I chose the 650w model. Even then if you are doing a little overclocking, you stay within the 90 percentile between 134w - 588w which is solid. So given the 750w model you can assume another 100w added to the 588w and you'll still be in the 90 percentile which is darn good!

    Of course, not all machines are running stock clocks.
  • 529th - Wednesday, April 14, 2010 - link

    JonnyGuru did a great review on the[rul=http://www.jonnyguru.com/modules.php?name=NDReview...]Seasonic X-650[/url]. The ripple suppression on these things are top notch. Check out page 3.

    Isn't he still a mod here?
  • MamiyaOtaru - Thursday, April 15, 2010 - link

    Got the 750 on ebay for 148 (with shipping) after cashback. Was quite a steal considering the MSRP

    power draw at the wall went from 153 to 123 at idle. Quite the change from my old aerocool zeroDBA.
  • jayce - Thursday, April 15, 2010 - link

    Are power supply manufacturer’s going to be moving towards switching topology between lower and higher loads?
    Given the trend in CPU’s/ GPU’s to use power gating and hard disk controllers spinning down disks when idle, are we going to be seeing power supplies which provide high efficiencies in 50w-150w and 400w+ in the case of a 750w power supply.
  • Bitgod - Sunday, April 18, 2010 - link

    I put together a new system using my old HX620 and I was getting squealing from various components. I decided to take a chance and try a new PSU and I knew I wanted one that was more efficient. I'd seen some of the pics of the inside of the X750 and fell in love with it, it's so clean. So I coughed up the money to get one, and luckily it was worth it because all the squealing noises went away. And it's also drawing less power according to the kill-a-watt tester I plugged it into. So, it's pricey, but if you want a good PSU, this is it.
  • Salsoolo - Thursday, June 3, 2010 - link

    thats a fine psu
    90+ all over over, thats amazing
  • jed22281 - Tuesday, June 22, 2010 - link

    I don't suppose any one could offer some thoughts based on my needs outlined in this thread of mine?
    http://www.jonnyguru.com/forums/showthread.php?p=6...
    Much appreciated if anyone can!

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