Review of mCubed T-Balancer in English

rperezlo · Post by **rperezlo** » Wed Sep 15, 2004 1:40 am

http://www.hardware-test.dk/test_show.asp?id=3147

Becks · Post by **Becks** » Wed Sep 15, 2004 9:55 am

http://www.madshrimps.be/gotoartik.php?articID=223

DrCR · Post by **DrCR** » Thu Sep 16, 2004 5:09 am

Wow, now that is a fan controller!

DrCR

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Edward Ng · Post by **Edward Ng** » Thu Sep 16, 2004 9:45 am

[H]ardcontroller.

DrCR · Post by **DrCR** » Thu Sep 16, 2004 11:14 am

Edward Ng wrote:[H]ardcontroller.

?

DrCR

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Edward Ng · Post by **Edward Ng** » Thu Sep 16, 2004 11:19 am

lol; it's a complement...

Goes by the [H]ardOCP theme.

DrCR · Post by **DrCR** » Thu Sep 16, 2004 12:14 pm

Ah, OK. Cool deal. :)

DrCR

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silvervarg · Post by **silvervarg** » Thu Sep 16, 2004 11:18 pm

It is really amazing that they manage to sell it at only 50 euro retail price. It looks like a great prize for such a good controller.
I would like to hear more about what the PWM frequency does to noise in fans, since this has been a major problem with many PWM based controllers.
I think this controller would be great for a SPCR review.

rperezlo · Post by **rperezlo** » Fri Sep 17, 2004 1:45 am

Changing the PWM frequency changes both the level and the frequency of the sound. Most of the people seems to find a comfortable spot around 80 Hz where the noise is not audible.

In any case mCubed also offers unexpensive electronic attenuators that essentially convert the T-Balancer in a non PWM device.

jones_r · Post by **jones_r** » Wed Sep 22, 2004 3:50 am

In any case mCubed also offers unexpensive electronic attenuators that essentially convert the T-Balancer in a non PWM device.

Convert what ?. I ordered the T-Balancer several days ago, but I didn't bought that cheap attenuator, because I didn't understand what does it do. Does it let you control the voltage when you can't change the PWM ?.

rperezlo · Post by **rperezlo** » Wed Sep 22, 2004 5:34 am

I'm not sure what you mean by changing the PWM...

A PWM fan signal is a square wave that has an amplitude of 12 V and a duty cycle that is variable. For instance, to achieve te equivalent of 2.4 VDC, you let the 12 VDC signal on 20% of the time and off 80% of the time, and so you get the same amount of energy that you would get in a signal that is 2.4 VDC and is on 100% of the time. This mechanism is not perfect, as the fan circuits are not designed to take a square wave instead of a DC signal and it may create audible noise due to resonance, etc.

The electronic attenuator converts from a PWM signal to a DC signal. Its input is the 12 V square wave of variable duty cycle and its output is a DC signal of variable level, as the one you would get with a resistive fanbus.

BTW, for all the PWM detractors, it is true that the noise issue is real and can make PWM unusable, or at least you have to choose your fans carefully. But PWM also has the advantage of allowing lower rotation speeds, as some fans will run well with a low duty cycle square wave but not with a low DC level signal of the same power.

Resume: I love my Globefans with PWM but I'm only reasonably happy with the results of PWM with my Artic Cooling CPU fan.

jones_r · Post by **jones_r** » Wed Sep 22, 2004 6:17 am

rperezlo, thank you very much for the clarification.

There is one thing I'm trying to figure out about the attenuator. You said:

The electronic attenuator converts from a PWM signal to a DC signal. Its input is the 12 V square wave of variable duty cycle and its output is a DC signal of variable level, as the one you would get with a resistive fanbus.

But in one other place I read that because the problem of PWM is noise which gets louder as you get down in frequency, the attenuator allows you to get down in Volt, let's say from 12V down to 5V, and when you are in 5V, then you can use a PWM with a higher frequency (duty cycle?), so there will be less noise.

If you have a fan that only allows you to get down to a certain frequency before it start to make noises, It does not gaurantee that it will perform better with the DC converter. Won't a safer procedure will be to first get down to from 12V, to 5V, because maybe that same frequency which caused a still too high RPM with 12 Volts, will produce a low enough RPM at 5 volts. If the RPM will still be too fast for you in 5V, THEN maybe it would be a good move to use the DC converter as last resort.

So which one is right ?, does the attenuator just reduce the voltage, or does it performs as a DC converter ?.

rperezlo · Post by **rperezlo** » Wed Sep 22, 2004 6:23 am

If you really need this level of detail I think you should ask tech support at mCubed. They used to answer in a matter of minutes (who knows now, they are becoming more popular).

And don't forget to let us know once they answer...

jones_r · Post by **jones_r** » Wed Sep 22, 2004 6:33 am

Ok, I will ask them.

Btw, about the Globe fans, are they quiet enough ?. I need a 120mm fan, and I thought of using the Nexus 120 mm Real Silent Case Fan as I've been told they are currently the quietest in the industry, but I have no clue if they will take lower frequencies without making noise.

rperezlo · Post by **rperezlo** » Wed Sep 22, 2004 8:16 am

The Globefans (model B1202512L-3M) work very well with PWM. I hear no noise at low speeds and they work down to 60 rpm. At high speeds they make a lot of noise but they also move a lot of air. They are one of the favorites in SPCR.

I don't know how this compares to the Nexus, or how the Nexus behaves with PWM. There are a number of posts and a recommended fan list in the 'Fans & Control' forums, you may want to check or to post there.

jones_r · Post by **jones_r** » Thu Sep 23, 2004 5:17 am

Ok, here is what mCubed had to say about the attenuator issue:

The PWM noise comes mostly with high frequencies. We are working with frequencies between 0 and 200. Some fans do a little rumbling at low speeds. That rumbling can be diminished with our attenuators which turn digital voltage into analog curves/waves.

How the attenuator works:
- T-Balancer does no analog conversion: then it would not be possible to reduce fan speed to almost 2%.
- T-Balancer does no voltage conversion: then it would not be possible to reduce fan speed to almost 2%.
- To reduce PWM noise we offer to adjust to PWM frequency, that means to change the time between the 12V signals.

But, the attenuator is making DC conversion! Sometimes the adjusting of the PWM frequency is not sufficient. But with the attenuator, everything works.

Another secret of the T-Balancer is: we have no pure PWM (rectangles): we have rounded up the edges of the rectangle to make it smooth.

We hope, that we could help you and that you will enjoy the T-Balancer!

Best regards,
Maik Berendt

rperezlo · Post by **rperezlo** » Thu Sep 23, 2004 6:10 am

According to Maik it seems that the attenuator converts PWM to DC, but the message is a bit confusing.

In any case, there are some good brains behind this box and this company. The PWM is smoothed, that may explain why we all seem to find a good frequency for the fans to work quiet. From this answer it seems that they have included in the mCubed design the capacitor sugested by some as the DIY solution to PWM noise.

You have in the same product the advantages of PWM (low speed) and of analog regulation (low noise) and you can choose channel by channel which one works better for your fans.

DrCR · Post by **DrCR** » Thu Sep 23, 2004 9:05 pm

rperezlo wrote:You have in the same product the advantages of PWM (low speed) and of analog regulation (low noise) and you can choose channel by channel which one works better for your fans.

Which is simply astounding!

You guys might be interested in this link:
http://www.mcubed-tech.com/deutsch/Luefterliste.html

DrCR

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DrCR · Post by **DrCR** » Thu Sep 23, 2004 9:10 pm

rperezlo wrote:The Globefans (model B1202512L-3M) work very well with PWM. I hear no noise at low speeds and they work down to 60 rpm. At high speeds they make a lot of noise but they also move a lot of air. They are one of the favorites in SPCR.

I don't know how this compares to the Nexus, or how the Nexus behaves with PWM. There are a number of posts and a recommended fan list in the 'Fans & Control' forums, you may want to check or to post there.

Do you have any experience with the Papst 4412? I talked with someone here comparing the 4412 to the Nexus120mm, and the Papst seems to have a sight edge. Now I'm curious as to how the Globe fairs againt the venerable 4412. The 4412 has been lauded as the choice for heatercore use where quietness is desired, but I'm open to other options.

DrCR

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Becks · Post by **Becks** » Thu Sep 23, 2004 11:42 pm

I should get some attenuators soon...... least i think they should be here soon... can't wait to play with them. Not sure exactly what i need them for, but they'll be fun to play with

rperezlo · Post by **rperezlo** » Fri Sep 24, 2004 1:23 am

The Papst seem to work better with the electronic attenuator according to the mCubed fans list. This means that they aren't so good with PWM.

I haven't tested them, so that I can't tell you how they work from a noise perspective. Check in the Fans & Control threads.

mpteach · Post by **mpteach** » Fri Sep 24, 2004 6:08 am

Interesting concept. DC voltage is completley smooth with no periodic changes in voltage and PWM waveforms are square and choppy. By partway converting or smoothing a PWM waveform you would get a smoother wave, sinewave-like. In Essense a PWM/DC hybrid with advatages of both. An antennuator would further smooth the waveform to be more DC-like.

DrCR · Post by **DrCR** » Fri Sep 24, 2004 8:20 am

rperezlo wrote:The Papst seem to work better with the electronic attenuator according to the mCubed fans list. This means that they aren't so good with PWM.

I haven't tested them, so that I can't tell you how they work from a noise perspective. Check in the Fans & Control threads.

Cool deal. Thanks.

DrCR

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teejay · Post by **teejay** » Tue Sep 28, 2004 2:55 am

I have an 80mm Papst (2000rpm, can't remember the exact type, 8412 something) hooked up to my T-Bal and it does suffer from PWM resonance. It is not very loud but definately audible and once you hear it you can't "un-hear" it. I ordered 2 attenuators (one for my VGA silencer) so this issue will probably be resolved soon, but I would not recommend the Papst without attenuator. The addition of PWM noise puts it on par with a regular cheap fan.

The 120mm Adda's in my case have no audible PWM side-effects, but the Coolermaster Aero fan (blower-type model) was unusable even at 95% speed. My secondary rig has 2 4412's and I have an aluminium Evercool lying around which I will try when I get around to it, but that won't be for a couple of weeks probably

Another note about Papst fans: IMO their quality is not consistent (I find 1 in every 3 fans too loud) so I will probably not be buying them anymore considering their price. Looking for an excuse to get Nexus...

DrCR · Post by **DrCR** » Tue Sep 28, 2004 8:27 pm

Thanks for your note about Papst quality issues. I guess then Nexus is an option for me again as is the Globe.

Edit: Here's where I heard the Papst 120mm had a slight edge over Nexus 120mm (towards the bottom of the page)
http://forums.silentpcreview.com/viewto ... highlight=

DrCR

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DrCR · Post by **DrCR** » Tue Sep 28, 2004 8:54 pm

rperezlo wrote:The Globefans (model B1202512L-3M) work very well with PWM...

What is the difference between this fan and the Globe "S1202512L-3M" Ralph Hutter used in the Thermalright XP-120 review (link)? Or is there not a difference and one is a typo?

I guess the B and S prefix is irrelevant?
http://www.globefan.com/12025.htm

Thanks!

DrCR

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Gholam · Post by **Gholam** » Tue Sep 28, 2004 9:08 pm

Hmmm, B/S prefix usually means ball/sleeve bearing.

DrCR · Post by **DrCR** » Tue Sep 28, 2004 9:17 pm

Ah, OK. Makes since.

I also came across a shootout between the Globe S1202512L-3M (they call it the earth fan instead of globe lol) and the Papst 4412. link

They ranked the Papst with higher marks since it was both very effective and quiet while the Globe was quieter but significantly less effective. They also say the "[Papst] breathes quality." But then again this review was in '02 so Papst quality might have indeed gone down.

Any thoughts?

teejay · Post by **teejay** » Tue Sep 28, 2004 10:18 pm

The quality decline for Papst fans is the general impression you get from reading this forum and based on my experience with 80mm fans I agree (I've used around 20 of these fans over a 3 year period). This however does not mean that they are low quality: they are very often more quiet than brandless or "brand-name-but-not-very-quiet" fans (Vantec Stealth anyone?) and have an expensive "feel", which could explain the "Papst breathes quality" remark. But so do Nexus fans or Titan/Evercool aluminium models. I generally go with what spcr tells me (both forums and the excellent reviews) and tend to ignore reviews on other sites when it comes to silence.

IMO the Papst and Nexus are comparable fans noise-wise, where the Papst offers higher airflow but also better undervoltability at a 35% higher price (for .nl that is). Note that this is an opinion not based on first-hand experience with Nexus yet. If you can bear to wait a few weeks I will get a few Nexus fans as a replacement for my Adda fans.

DrCR: Not to complicate things for you, but have you considered the Titan (Europe)/Evercool (USA) aluminium fans? It gets quite some praise around here. I have one but never used it in a quiet setup... yet.

DrCR · Post by **DrCR** » Wed Sep 29, 2004 8:14 am

Yeah, the Evercools are good esp. in the <5V range. I stock some of them at work (IT) along with some Japanaflos. But I heard the Evercools aren’t the best choice for a restrictive application (like the heatercores I'm going to be using).

Yeah, I would love to hear how you like the Nexus fans when you get them in! PM me or reply to this thread when you post about them would you? I only occasionally have time for forum browsing during uni and I really don’t want to miss what you have to say. Thanks!

So right now, for the heatercores, I'd like to pair them with the Papst 4412. Think I’ll have to buy extra ones to make sure I get quiet ones? How well the Papsts work on the T-balancer+ attenuator concerns me. Should it not concern me? Will the Papsts work just fine on the T-balancer if the attenuator is use?

If there is a problem with the Papsts on the T-balancer+attenuator and I really want to go for the T-balancer route, then I'll get the Globes perhaps Nexus depending on what you post teejay.

Now for my case fans (probably two 120mm fans) I'll be going for whatever is the absolute quietest with little regard to CFM. The Papst 4412 power to noise ratio becomes irrelevant here, and I doubt I would go for it. Right now the Globe and the Nexus fans are what I have in mind. Perhaps an Evercool. I did hear that Nexus 120mm had a clicking problem at minimum voltage though, but I heard the same thing about the Globe. Looking forward to what you have to say in a few weeks teejay!

DrCR

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