Internal Design and Components

The interior has many indicators that this is a Seasonic-made power supply. First, there is only one DC-to-DC PCB for +3.3V and +5V instead of two. We saw this in the M12D 850W. Furthermore, the filtering behind the entrance is almost identical to the S12D design.

Interesting to note are the two different solder points for +12V. At one point we can find yellow and black cables and a "12V2" silkscreen on the PCB—just like the S12D design. That means this isn't a real single-rail PSUm and in fact most PSUs aren't multi-rail designs. Instead, they share the current between more than one output rail. That makes the design a modern version of the S12D layout. The heatsinks are smaller and the main caps as well as the DC-to-DC VRM are displaced, but otherwise they're very similar.

Transient filtering starts behind the AC inlet and continues on the mainboard. There are two X-capacitors, three coils (one is a current-compensated version), and six Y-capacitors. Six caps sounds very helpful here but we have to keep in mind that the leakage current on ground shouldn't get too high. Otherwise, we get a "dirty ground" contact that can create issues; remember that EMC doesn't necessarily equate with safety. You'll want to look at the impedance of the disturbing source, the type of problem, and the input characteristics of your power grid to choose the right components. Quantity can only be effective in combination with precision. Ultimately, having six Y-capacitors isn't a guarantee that a PSU is good PSU, but they are very good against common mode interferences. Let's move on to the power factor pre-regulator.

Here we find two GBU806 (GBU case, 8A forward) for rectifying and two very large Rubycon caps. Like nearly all modern PSUs, the TX750 has active PFC. All transistors have very common ratings so there is nothing special needed to reach 80 Plus Bronze. In the secondary circuit we find the usual five diodes in a TO-220 housing. Again there's no need for anything unusual like synchronous rectifying. The controlling circuit, incidentally, is located at the bottom of the picture, which is another modification of the M12D design. Some of those larger capacitors lean but most components are fixed well.

Appearance, Cables and Connectors Voltage Regulation and Quality
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  • tomoyo - Monday, May 16, 2011 - link

    It's definitely a pretty big improvement, this has been discussed on some other review sites such as jonnyguru. The TX750 v2 is a good seasonic design, the old TX750 is an older cwt design that was not a great performer. This is an awesome budget psu. Reply
  • JarredWalton - Monday, May 16, 2011 - link

    I linked in our old TX750 review for comparison; this is a much improved product. Reply
  • Patrick Wolf - Monday, May 16, 2011 - link

    So is this review suggesting that it not being a single rail as being a bad thing? Or just that it's specs are incorrect? I mean it's better this way. If it were single rail, the amperage on the +12V would be to high and OCP wouldn't be included, splitting the rails allows for this additional protection. Corsair shouldn't lie to the customer, but I understand why they would as most people still think single rail is superior. At least they're not claming it's multi-rail when the rails are actually combined. Reply
  • Martin Kaffei - Tuesday, May 17, 2011 - link

    Just the specs, basically there are no disadvantage for customers. Otherwise the conclusion would have been worse for Corsair. It's still a good PSU. Reply
  • Guspaz - Tuesday, May 17, 2011 - link

    No disadvantage, except that consumers now need to worry about balancing rails. Single-rail designs provide the huge benefit of obviating consumers of the need to worry about if they've put too much stuff on one rail instead of the other. Reply
  • Martin Kaffei - Tuesday, May 17, 2011 - link

    Nobody needs to worry about the loads. There are just as many connectors as a rail is able to provide. Even if Corsair wants to change something with the configuration the engineers take a look at it first before they sell a single product. Reply
  • erple2 - Tuesday, May 17, 2011 - link

    I think there's plenty of research that suggests that a high quality multi-rail PSU is just as good as a high quality single-rail PSU.

    There are a few exceptions where a single-rail PSU is "better", but that generally refers to instances where you are running a LOT of devices that feed off the 12V rail (10's of harddrives, fancy cooling, 3x+SLI or 3x+ CrossFire, etc).

    The other part, however, (truth in advertising) is very important. If' it's a single rail PSU, advertise as such. If it's really a multi-rail PSU, advertise it as such.
    Reply
  • Erbadios - Monday, May 16, 2011 - link

    That is odd...

    My manual states that the version 2 of TX 650, 750 and 850 comes with a 140mm fan.

    My TX650 v2 does seem to have a very large fan, but i didn't open it to acually check...

    So far i like it a lot, it's somewhat quiet. I wonder if the 750TX differs a lot from the 650TX, though..
    Reply
  • MeanBruce - Monday, May 16, 2011 - link

    The smartest choice you can make is to just wait until this summer when the Corsair Professional Series Platinum debuts. Sure they cost more but well worth it over the 7year warranty period in energy savings alone!;) Reply
  • JarredWalton - Monday, May 16, 2011 - link

    Just to do the math:

    Bronze vs. Platinum: 85% vs. 91% (give or take)

    Assume an average daily load of 150W (idle most of the time), and we'll even let the system run 24/7. That works out to:

    Bronze: 1547 KWh per year
    Platinum: 1429 KWh per year

    Assuming $0.10 per KWh, you would save $11.80 per year.

    If you actually leave your PC on 24/7 and draw 150W or more, I suppose it could be worthwhile to upgrade to Platinum. Realistically, though, I think Bronze/Silver is more than sufficient. Just my opinion, though.
    Reply

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