I needed a new FLEX power supply for my RCC-SMALL2
project and I know some of you are also looking for alternatives to the famous ENHANCE 7660B.
Some time ago I spotted a promising new FLEX PSU on TaoBao which is supposed to deliver up to 700W. The manufacturer is a Chinese Company called "Extreme Cat Electronics" (极致猫电子) and they are already in the business for some time. The company is mainly doing OEM, so their PSUs sell under different names / brands. The one I got sells as MF-700F
but some sellers like YTC also just call it 7760B
So let's have a look what we can get for CNY 700,- (ca. USD 110,-) ...
the PSU comes with modular soft white cables, which should fit for most builds
the manufacturer claims 700W max output and 90+ efficiency so let's have look what's inside...
I am pleasantly surprised that they use quite good brand components and nothing "no-name" like many other TaoBao FLEX PSUs I have seen before. Overall I think the price of ~110 USD is fair, I wouldn't pay more though. The small heatsink is a good indicator that it has a decent efficiency. I am not so happy that the screw locking washer for the grounding wire is missing. Normally that is mandatory if they want to get a CE certificate so I doubt the CE they printed on the label is legit.
Just FYI, below is the "METALFISH 500W FLEX" PSU for comparison. Guess even if you have no idea about power supplies you can tell that there is a big quality difference.
The side view reveals an SRC/LLC+SR Controller which is another indicator that it really has 90+ efficiency.
Some things that should be improved IMO: one of the smaller caps is touching a solder spot and the wires from one of the buck chokes are touching a screw on this heatsink there. Although that this seems to be no issue I would feel more comfortable having some insulation or creepage distance there.
soldering quality looks clean, not too much tin and no cold solder spots
fan / noise: I could not find any datasheet for the fan they are using but it seems to be a 9000RPM one which sounds like a jet engine at full RPM. The fan is silent in idle but starts to make a high pitched unpleasant sound when going over 200W.
It is controlled by the output load, not by temperature so keep that in mind if you want to do a fan swap
. Update: the fan is temperature controlled and will ramp up from 20% @ 30C to 100% @ 60C. At full load, that tiny fan needs to get rid of ~75W heat and a Noctua 5000RPM fan just can not do that. I haven't tested it yet but I would guess you should be OK with a Noctua fan up to 400W load.
for PSUs it's important that materials used are UL approved / flame retardant so I am glad to see that the insulating materials do not burn
if you are interested, the manufacturer "Extreme Cat" also did some own videos showing the performance and internals of his PSUs, thanks @tinyitx
I'll post an update here once I did a a fan swap and tested the PSU for some time.
My thoughts so far:
this one is probably the best Chinese TaoBao FLEX PSU I have checked so far but is it worth to buy? Well, consider this...
- VELKA is selling the original ENHANCE 7660B for USD 160,-
- The MF-700F sells for 700,- CNY (ca. 110,- USD) on TaoBao plus you have to use Superbuy and pay a lot for shipping, perhaps also customs / import fees
- If there are quality issues, you would have to return it to China on your own cost and waiting a long time to get it repaired / replaced
- unless it has to be black and modular, modded second hand 500W ~ 600W FLEX server PSUs are much cheaper and also do the job
to be continued....