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rperezlo
Joined: 27 Feb 2004
Posts: 89
Location: Madrid, Spain
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Becks
Joined: 01 Mar 2004
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DrCR
Joined: 13 Jun 2004
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 Posted: Thu Sep 16, 2004 5:09 am Post subject: |
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Wow, now that is a fan controller! 
DrCR
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Edward Ng
SPCR Reviewer
Joined: 11 Dec 2003
Posts: 2696
Location: Scarsdale, NY
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DrCR
Joined: 13 Jun 2004
Posts: 533
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| Posted: Thu Sep 16, 2004 11:14 am Post subject: |
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| Edward Ng wrote: | | [H]ardcontroller. |
? 
DrCR
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Edward Ng
SPCR Reviewer
Joined: 11 Dec 2003
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Location: Scarsdale, NY
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DrCR
Joined: 13 Jun 2004
Posts: 533
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| Posted: Thu Sep 16, 2004 12:14 pm Post subject: |
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Ah, OK. Cool deal. :)
DrCR
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silvervarg
Joined: 03 Sep 2003
Posts: 1283
Location: Sweden, Linkoping
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| Posted: Thu Sep 16, 2004 11:18 pm Post subject: |
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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.
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Passive XP2500+: Convection cooled, ~XP1500+, DP-102 cooler, Abit NF7-M, CNPS6000Cu on NB, Antec Overture, Samsung P80 120GB |
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rperezlo
Joined: 27 Feb 2004
Posts: 89
Location: Madrid, Spain
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| Posted: Fri Sep 17, 2004 1:45 am Post subject: |
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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. |
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jones_r
Joined: 17 Sep 2004
Posts: 140
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| Posted: Wed Sep 22, 2004 3:50 am Post subject: |
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| Quote: | | 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 ?. |
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rperezlo
Joined: 27 Feb 2004
Posts: 89
Location: Madrid, Spain
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| Posted: Wed Sep 22, 2004 5:34 am Post subject: |
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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. |
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jones_r
Joined: 17 Sep 2004
Posts: 140
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| Posted: Wed Sep 22, 2004 6:17 am Post subject: |
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rperezlo, thank you very much for the clarification.
There is one thing I'm trying to figure out about the attenuator. You said:
| Quote: | | 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 ?.
Last edited by jones_r on Wed Sep 22, 2004 6:23 am; edited 1 time in total |
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rperezlo
Joined: 27 Feb 2004
Posts: 89
Location: Madrid, Spain
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| Posted: Wed Sep 22, 2004 6:23 am Post subject: |
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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... |
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jones_r
Joined: 17 Sep 2004
Posts: 140
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| Posted: Wed Sep 22, 2004 6:33 am Post subject: |
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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. |
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rperezlo
Joined: 27 Feb 2004
Posts: 89
Location: Madrid, Spain
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| Posted: Wed Sep 22, 2004 8:16 am Post subject: |
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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. |
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jones_r
Joined: 17 Sep 2004
Posts: 140
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| Posted: Thu Sep 23, 2004 5:17 am Post subject: |
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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 |
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rperezlo
Joined: 27 Feb 2004
Posts: 89
Location: Madrid, Spain
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| Posted: Thu Sep 23, 2004 6:10 am Post subject: |
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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. |
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DrCR
Joined: 13 Jun 2004
Posts: 533
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| Posted: Thu Sep 23, 2004 9:05 pm Post subject: |
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| 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
Joined: 13 Jun 2004
Posts: 533
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| Posted: Thu Sep 23, 2004 9:10 pm Post subject: |
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| 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
Joined: 01 Mar 2004
Posts: 76
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| Posted: Thu Sep 23, 2004 11:42 pm Post subject: |
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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  |
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rperezlo
Joined: 27 Feb 2004
Posts: 89
Location: Madrid, Spain
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| Posted: Fri Sep 24, 2004 1:23 am Post subject: |
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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. |
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mpteach
Joined: 22 Dec 2003
Posts: 426
Location: CT USA
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| Posted: Fri Sep 24, 2004 6:08 am Post subject: |
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| 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. |
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DrCR
Joined: 13 Jun 2004
Posts: 533
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| Posted: Fri Sep 24, 2004 8:20 am Post subject: |
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| 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
Patron of SPCR
Joined: 02 Aug 2004
Posts: 749
Location: The Netherlands
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| Posted: Tue Sep 28, 2004 2:55 am Post subject: |
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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...
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I: E5200 OC, Ninja II, Gigabyte P45, ATi HD4850 w/ S1, Raptor + Samsung disks in Quiet Drive, Enermax Modu82+ 425W, Lian Li V1000, 2x Nexus 120 PWM
II: A64 3000+, Ninja, DFI nForce3, headless, Samsung disks suspended, Enermax Pro82+ 385W, Antec 3000B padded & dampened, 2x Nexus 120 B&W |
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DrCR
Joined: 13 Jun 2004
Posts: 533
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| Posted: Tue Sep 28, 2004 8:27 pm Post subject: |
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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/viewtopic.php?t=15315&highlight=
DrCR
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DrCR
Joined: 13 Jun 2004
Posts: 533
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| Posted: Tue Sep 28, 2004 8:54 pm Post subject: |
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| 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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Last edited by DrCR on Tue Sep 28, 2004 9:18 pm; edited 2 times in total |
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Gholam
Joined: 26 Apr 2004
Posts: 155
Location: Israel
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| Posted: Tue Sep 28, 2004 9:08 pm Post subject: |
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| Hmmm, B/S prefix usually means ball/sleeve bearing. |
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DrCR
Joined: 13 Jun 2004
Posts: 533
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| Posted: Tue Sep 28, 2004 9:17 pm Post subject: |
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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? |
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teejay
Patron of SPCR
Joined: 02 Aug 2004
Posts: 749
Location: The Netherlands
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| Posted: Tue Sep 28, 2004 10:18 pm Post subject: |
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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.
_________________
I: E5200 OC, Ninja II, Gigabyte P45, ATi HD4850 w/ S1, Raptor + Samsung disks in Quiet Drive, Enermax Modu82+ 425W, Lian Li V1000, 2x Nexus 120 PWM
II: A64 3000+, Ninja, DFI nForce3, headless, Samsung disks suspended, Enermax Pro82+ 385W, Antec 3000B padded & dampened, 2x Nexus 120 B&W |
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DrCR
Joined: 13 Jun 2004
Posts: 533
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| Posted: Wed Sep 29, 2004 8:14 am Post subject: |
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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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