Zalman ZM600-HP

[Jon Gerow]

Gabe over at Hardware Secrets just put up a "review" of the Zalman ZM600-HP... as usual, he's taken it completely apart.

I have one for review, and have already shot photos of it. So if there's anything you wanted to see that you didn't see in Gabe's pics, maybe you'll find it in mine.

[Jon Gerow]

As you can see, so far the Zalman looks rather different inside than other FSP Epsilon based units.

The heatpipe is a great idea IMHO, as it moves heat away from the typical "hot spot" that some PSU's have and that require the Seasonic M-12 to have the 60MM fan in the front.

[Oklahoma Wolf]

There are some rather intriguing differences that I can see so far between the Zalman and the Epsilon sitting next to me. But at the same time, it's also intriguing to me that the primary side looks almost identical, if not totally identical.

The biggest differences I can see are on the secondary side. In the Epsilon, the 12v output so far doesn't look to have a proper pi filter on it. It has the coil and the output caps, but not the input cap that I have found. Unless the input cap is the wee little 1000uF 16v cap next to the big coil that is. The 12v output is filtered by two OST 2200uF caps in parallel.

This isn't what I'm seeing on the Zalman - it appears to have the same filtering on the 12v output, but with one major difference... one of the 2200uF OST caps looks to have been replaced with no less than four Teapo 470uF caps. Whether they're in parallel too is uncertain, but very likely.

This may be FSP addressing the ripple issue. I hold Teapo in higher regard than OST, and it may be these four caps that are the key to the lower ripple measurements on the Zalman I've seen at other review sites. If this is true, I think it may be possible to modify early Epsilons to kill the ripple bug. I'll be experimenting with this fairly soon on this here Epsilon 600W I have next to me.

3.3v/5v outputs look to have been beefed up too - the cap values are higher.

Edit - forgot to add my pic of the Epsilon secondary.

[Jon Gerow]

Ripple results won't be until after T-Giving and Matt is done with using my Stingray for a couple PSU reviews I've assigned to him.

I had no idea I would get so many more PSU's to review this month. Between this and my EarthWatts, jonnyGURU.com is going to have a very good year.

[Oklahoma Wolf]

No problem... I'll go by SPCR's readings for now

Posted a question about modding the Epsilon over at Badcaps... at the moment I'm thinking just the better grade of caps alone is going to help, but I may want to up-rate them too if I can be sure it won't be to the detriment of the unit's design.

[Super Nade]

Wolf, in the pic you posted, any idea why the choke has two different guage windings on it? I have not seen this before.

[Oklahoma Wolf]

If I'm getting my electronics engineering right, it's just two coils on one winding. One will be for 12v, the other for 5v. Space was obviously at a premium in this design, or I imagine they'd have set up three pi filters to do indy with

[Super Nade]

Wolf, do you think the following alternative possibility makes sense?
This looks to be a classic EMI supression scheme and I would idenify it as a common-mode (live/neutral with GND) inductor. If I understand this correctly, Common mode inductors are usually wound with two windings of equal numbers of turns. The windings are placed on the core so that the line currents in each winding create fluxes that are equal in magnitude but opposite in phase. These two fluxes cancel each other and supress hysteretic effects (magnetic field with memory).Ofcourse, I don't have the unit in front of me so I'm guessing.

[Oklahoma Wolf]

Yep, that's what a pi filter is supposed to do... suppress ripple and high frequency noise. Starting to think the input cap is actually that third OST 2200uF.

[Super Nade]

Isn't that a bit small though?