The Papst 80mm fans are actually quieter than the 60mm. At 12V/1500RPM the fan produces 12dB(A). At 8V it is almost silent. At 8V, with the inlet and outlet baffled 90°, I can't hear them.
Anyway I think it is rather limiting to think the amps need to be in the listening room. I wouldn't mind hanging them from the ceiling of the basement.
Anyway I think it is rather limiting to think the amps need to be in the listening room. I wouldn't mind hanging them from the ceiling of the basement.
A friend of mine worked for Cello in L.A. I never noticed the fans in their amps, even when there was no music. Special Mark Levinson fans?
The 60mm Papst (type 612L) that I used is specified with 16db(A) @ 15V/2650RPM. Even with much lower voltage (less speed) I was able to hear it in free air at 3m distance and I´m sure in an amp housing it doesn`t become any better regarding noise.
I'm not that hesitant to use fans and one of my amps will be using them. If used properly I don't think they are such a nuisance.
Ah, Ah, Ah, Peter forgot to 😉 that time!
That's how I am slowly making my way up to the "enlightened" status!
That's how I am slowly making my way up to the "enlightened" status!
By the way, if anyone else wants to try this and is going to use liguid filling, remember those pump up water filled rockets when we were kids...make sure the cans don't have any air trapped!
It appears that they will dissipate one Calorie each can for a total
of 8 calories. Note that these would be your large nutritional calorie also known as a kilocalorie.
😉
of 8 calories. Note that these would be your large nutritional calorie also known as a kilocalorie.
😉
Power rating
Let's see now.....
If I read those cylinders correctly, they're one calorie each. So that would be 8 calories/hr or .0000015 horsepower.
[641.4 kcal/hr = 1hp]😀
If you don't like those units, 1W=.001341 hp. So in those terms, that amp should dissipate .001633 Watts
Let's see now.....
If I read those cylinders correctly, they're one calorie each. So that would be 8 calories/hr or .0000015 horsepower.
[641.4 kcal/hr = 1hp]😀
If you don't like those units, 1W=.001341 hp. So in those terms, that amp should dissipate .001633 Watts
papst
Hi,
the 2 papst 8412 NGL (12dBA) run at 9V in my Aleph 5 and can´t be heard from a distance more than 1m. They are quite effective in reducing Rth from around 0.35 to 0.2. The transformers in my old amp were louder than this! I mounted them on small silent blocks to reduce vibration.
The only thing I don´t like about fans is the way they collect dust wich means you´ll have to clean them once or twice a year.
william
Hi,
the 2 papst 8412 NGL (12dBA) run at 9V in my Aleph 5 and can´t be heard from a distance more than 1m. They are quite effective in reducing Rth from around 0.35 to 0.2. The transformers in my old amp were louder than this! I mounted them on small silent blocks to reduce vibration.
The only thing I don´t like about fans is the way they collect dust wich means you´ll have to clean them once or twice a year.
william
One more thing with fans, I would highly recommend a fan speed sensor, so that if the fans die, you will know it (or have it cut power to the amplifier). If the fans are quiet and out of sight, then you might not know until it gets too late when your fans die. I had a friend lose his computer over spring break one year, because he left his computer on and his cpu fan died.
--
Brian
--
Brian
DC fans have a speed which is somewhat proportional to
the supply voltage, thus you can easily throttle them down
until they are much more quiet while still delivering some
air flow. Larger fans with ball bearings are better at this.
At some arbitrarily low voltage, they will kick off, and it takes
a larger voltage to get them going, so some regulation is
definitely needed, particularly as the fans vary.
Many modern fans come with a quadrature tachometer which
can be used to sense fan speed. You can differentiate the
pulses, rectify them, integrate them, and use this to drive
a Mosfet Gate. The Drain attaches to the (-) terminal of the
fan and the + terminal is attached to the supply. The Source
attaches to ground.
Voila! An 8 part fan speed controller: 2 caps, 2 diodes, 3
resistors and a Mosfet.
😎
the supply voltage, thus you can easily throttle them down
until they are much more quiet while still delivering some
air flow. Larger fans with ball bearings are better at this.
At some arbitrarily low voltage, they will kick off, and it takes
a larger voltage to get them going, so some regulation is
definitely needed, particularly as the fans vary.
Many modern fans come with a quadrature tachometer which
can be used to sense fan speed. You can differentiate the
pulses, rectify them, integrate them, and use this to drive
a Mosfet Gate. The Drain attaches to the (-) terminal of the
fan and the + terminal is attached to the supply. The Source
attaches to ground.
Voila! An 8 part fan speed controller: 2 caps, 2 diodes, 3
resistors and a Mosfet.
😎
...it doesn't take much airflow to make a big difference to the cooling either. Just the slightest breeze over a heatsink will have a dramatic effect on it's Rth compared to stagnant air (which is circulated by convection alone). This is because any air movement helps break up the boundary layer clinging to the heatsink surfaces. The boundary layer is a thin layer of air on each surface which tends not to move, thus insulating and trapping heat in. Just a tiny turbulence is all it takes to break up this boundary layer and get the heat really flowing.
Charles BL:
Maybe I could help you... Cooling Beer Cans, but I'd have to dig up my old notes first! 😉
Maybe I could help you... Cooling Beer Cans, but I'd have to dig up my old notes first! 😉
Aleph X
Hello!
First: Yes I have searched...
Q: With X 🙂confused: ) number of X-constructions around, please tell me: can they all be scaled up to 150+W ?
How big / small is the "X" change compared to a "normal" ALEPH? Or: can a "normal" ALEPH be modified into "X"?
Is there any "energy-saving" (push-pull) Alephs / X? (150-250W-class)-(getting close to what my wall can deliver...).
Arne K
Hello!
First: Yes I have searched...
Q: With X 🙂confused: ) number of X-constructions around, please tell me: can they all be scaled up to 150+W ?
How big / small is the "X" change compared to a "normal" ALEPH? Or: can a "normal" ALEPH be modified into "X"?
Is there any "energy-saving" (push-pull) Alephs / X? (150-250W-class)-(getting close to what my wall can deliver...).
Arne K
Where you are you could probably use all the heat generated by a 150 watt aleph-x.
Maybe you should look at the passdiy site and build the "zen with the lamps" to get you through the dark days.
thanks Nelson, for a great site
Maybe you should look at the passdiy site and build the "zen with the lamps" to get you through the dark days.
thanks Nelson, for a great site
Cobra2,
You can scale Aleph X the same way as regular Aleph to whatever power level you feel comfortable with. No push-pull Aleph though.
You might look at non-Aleph, X series amps which were push-pull. Maybe one day we'll see the schematics on PassLabs site.😉
You can scale Aleph X the same way as regular Aleph to whatever power level you feel comfortable with. No push-pull Aleph though.
You might look at non-Aleph, X series amps which were push-pull. Maybe one day we'll see the schematics on PassLabs site.😉
oude wijn in nieuwe zakken?
old wine in new bottle?
old dude in new jacket?
The picture of the old dude...similar sort of humor...who can guess who StStone is? New IP address though, a copycat maybe?😉
old wine in new bottle?
old dude in new jacket?
The picture of the old dude...similar sort of humor...who can guess who StStone is? New IP address though, a copycat maybe?😉