Zalman PSU not as quiet as it claims?

forumx · Post by **forumx** » Tue Mar 29, 2005 11:24 pm

I recently installed the Zalman 300W PSU (ZM300B-APS) on my PC. I am dissappointed that the unit is not exactly noise-free, as claimed by the manufacturer. Although it is quieter than my old PSU, I can still hear the fan, even standing 5 metres away from the PC. Also I do not notice any variation in the fan noise, as opposed to the fact that it is temperature controlled. The noise is definitely from the PSU as I have already replaced both the CPU and the case fans with almost silent fan replacements.

Does anyone else notice this problem or do I have a faulty unit? I expect much better results from Zalman.

Any comments will be much appreciated.

ultraboy · Post by **ultraboy** » Wed Mar 30, 2005 3:27 am

From this SPCR's Recommended PSUs list, Zalman ZM 300A-APF was given a 7 on Noise scale while Zalman ZM 400B was given a 6+ on similar scale.

This is very much in line with what you feel.

Btw, Welcome to SPCR!!! - though I wish I could make the welcome on a happier note.

niels007 · Post by **niels007** » Wed Mar 30, 2005 4:58 am

Zalman is indeed 'better than most', but out of the box not often good enough for the Silence Purist. Mostly you have to change the fans and then they get really good.

Most of the time you will find that brands like Seasonic, Nexus and FSP have better and less noisy powersupplies in their lineup. Thermalright has better cpu heatsinks. Neither of these brands is as readily available in the average high street store as Zalman though, and Zalman is decently priced..

~El~Jefe~ · Post by **~El~Jefe~** » Wed Mar 30, 2005 6:58 am

niels007 wrote:Zalman is indeed 'better than most', but out of the box not often good enough for the Silence Purist. Mostly you have to change the fans and then they get really good.

Most of the time you will find that brands like Seasonic, Nexus and FSP have better and less noisy powersupplies in their lineup. Thermalright has better cpu heatsinks. Neither of these brands is as readily available in the average high street store as Zalman though, and Zalman is decently priced..

a panaflo installed in one of these makes one of the most silent psu's around.

Just i ask myself, who wants to bother with that??

I have a 300watt one, it isquieter, alot more so than decent brands like antec and coolermaster put in their standard machines. Zalman's also can be purchased for kinda cheap. if you are good with working with lethal levels of charged parts inside a psu, I think this is the cheapest option for a quiet psu.....

StarfishChris · Post by **StarfishChris** » Wed Mar 30, 2005 7:32 am

~El~Jefe~ wrote:if you are good with working with lethal levels of charged parts inside a psu, I think this is the cheapest option for a quiet psu.....

You should always discharge your PSU first, though it might not be as cheap (to replace the electricity lost

)

Since all PSU manafacturers will make sure that more airflow than necessary is being provided - bodge factor - you can always make fanned PSUs quieter. You just have to make sure you choose the right fan for the job.

teejay · Post by **teejay** » Wed Mar 30, 2005 7:51 am

~El~Jefe~ wrote:a panaflo installed in one of these (TJ: a Zalman ZM300B-APS) makes one of the most silent psu's around.

Just i ask myself, who wants to bother with that??

Who? Well, let me see... most SPCR regulars? A fan swap is a very common PSU mod for the SPCR crowd and is not as dangerous as you seem to imply. You do have to be careful, but there is tons of info around here on how to do a swap safely.

Anodyne · Post by **Anodyne** » Wed Mar 30, 2005 7:58 am

I replaced an old Antec 300W that came with my case with a Zalman 400B last year and was pretty disappointed. If there was any difference in noise levels it was very minimal. The power supply is still the loudest component in my system; I look forward to an Antec Phantom as soon as I can mortgage my house for one. On the plus side, I have absolutely no complaints about the Zalman's stability or performance.

I should probably look into how to swap out the fan with a Panaflo. Will it really make that much of a difference? I also hope to move to a Lian-Li style reverse ATX case later this year (or that new Antec) which would give the power supply its own airflow...maybe that will bring the fan speed down.

sthayashi · Post by **sthayashi** » Wed Mar 30, 2005 8:01 am

Anodyne wrote:I should probably look into how to swap out the fan with a Panaflo. Will it really make that much of a difference? I also hope to move to a Lian-Li style reverse ATX case later this year (or that new Antec) which would give the power supply its own airflow...maybe that will bring the fan speed down.

Yes, this will make a difference.

And just for the record, it's not at all unusual to do a fan swap on the Seasonic Super Silencer series, one of SPCR's favored PSUs.

teejay · Post by **teejay** » Wed Mar 30, 2005 2:11 pm

I used to run my ZM400A in my Lian Li PC-V1000 like you proposed, Anodyne. The Zalman was running with a Nexus 80mm hooked up to the fan controller circuitry of the PSU. This definitely made a noticable difference on the noise signature. Under normal use the fan ran at ~900rpm and went up to ~1200 under load, so if you have a Nexus handy you can (sort of) predict the noise level. I don't think I'd recommend the Nexus fan for a PSU fan unless you have something of a duct for fresh air, though.

Like ultraboy posted before, a stock ZM400 only scores a 6+ on the recommended list, which makes it better than some but not top of its class. However, it can be run quite reliably with a Nexus fan and will be much quieter. In my next case I intend to externalize the fan to reduce air turbulance noise, since that is the biggest noise maker under these reduced airflow circumstances... or so it seems (I still have to find out

)

forumx · Post by **forumx** » Thu Mar 31, 2005 2:41 am

Thanks for all the replies. It sounds like the noise is pretty normal with Zalman PSU. I am considering replacing the fan as I have the PC in my family room 24 hours a day and would very much appreciate a quiet system.

For those who have replaced a Zalman PSU fan before, is it as simple as opening up the unit, unscrewing and unplugging the existing fan and replace it with a quieter one? Does it have a standard plug?

Also, would the temperature control still works?

Thanks in advance for your help.

teejay · Post by **teejay** » Thu Mar 31, 2005 6:13 am

Nope, no standard plug, sorry (at least, not on my 400... maybe the 300 is different). You'll have to cut the existing fan leads and splice/solder/connect the wires of your new fan. I prefer soldering combined with heatshrink wrapping myself, but that is just a personal thing... just make sure the new connections are secure and won't touch anything else.

The temp controls works fine like that as I wrote in my previous post. You can even run the rpm control wire outside the PSU and hook it up to your motherboard or something to view the fan speed in your favorite monitoring app... but that might be taking it a bit too far in your case.

Viperoni · Post by **Viperoni** » Thu Mar 31, 2005 6:43 am

Completely agree, my 400B isn't that quiet.
I'm willing to bet it'd work fine with a 80mm Panaflo L @ 7v though.

Uberapan · Post by **Uberapan** » Thu Mar 31, 2005 8:41 am

The Zalman is indeed loud, especially when it gets hot. I recommend replacing it with a Silverstone Fanless 300W PSU. That must be one of my best purchases ever, and you don't even have to void your warranty to make it quiet!

Chris`I · Post by **Chris`I** » Thu Mar 31, 2005 10:00 am

Fan swaps, although scary (esp in a PSU) are really not that hard. It took me ages to decide to change my Antec TruBlue fans out, but after swapping them with 2x panaflo, its dead quite. I can only hear it late on a night. It makes a lot more difference than you think! The fans are now running one @5v and one on the PSUs controller.

forumx · Post by **forumx** » Thu Mar 31, 2005 3:20 pm

Uberapan mentioned about the Silverstone fanless PSU. I have always worried about the heat it generated within the system. For my system, the only fan apart from the PSU and CPU is a 8cm case fan. Do you think that will be sufficient for using a fanless PSU?

Devonavar · Post by **Devonavar** » Thu Mar 31, 2005 4:58 pm

forumx wrote:Uberapan mentioned about the Silverstone fanless PSU. I have always worried about the heat it generated within the system. For my system, the only fan apart from the PSU and CPU is a 8cm case fan. Do you think that will be sufficient for using a fanless PSU?

Probably not, but it depends on what you're running (and how you use your system). Generally, if you don't have experience designing case airflow its better to avoid fanless power supplies, as they *do* require a source of airflow. It's quite possible (and less expensive) to construct a quiet (or even silent) system using a PSU with a slow, low airflow fan.

forumx · Post by **forumx** » Thu Mar 31, 2005 7:41 pm

Sounds like good advise. Think I'll stick to replacing the PSU fan on the Zalman.

Thanks for the reply.

forumx · Post by **forumx** » Thu Mar 31, 2005 8:49 pm

Just have another thought. Can I replace the PSU fan with one that is powered by an external source, eg. a 4-pin plug. This way, there is no soldering involve and I can also hook up a speed controller to it. This is assuming I have to diconnect the original fan by cutting the wiring.

Wondering if this is workable...

teejay · Post by **teejay** » Thu Mar 31, 2005 10:44 pm

Sure, that would work. Did that on my old Q-Tec PSU since it had no thermal regulation... hooked up the swapped Nexus 80mm to a fan controller outside the PSU so I could do the regulation myself. Just don't forget to make sure the cut wires of the original fan won't make contact with anything inside the PSU since they still give of ~12V. You can do this by applying a bit of electricians tape or something similar.

Easier to do and works almost as well... only thing you lose is the thermal regulation.

IsaacKuo · Post by **IsaacKuo** » Thu Mar 31, 2005 10:51 pm

Note that losing thermal regulation can be a good thing! The constant whirring sound of a fixed undervolted fan can be less noticeable than the sound of a quieter fan ramping up or down depending on the system load.