Did they come black anodized or did you send them out? I cannot locate these either on Antek's Ebay store or the website....
Did you contact them directly and ask about purchasing these individually?
I'm considering these for a mini aleph build
Thanks
Wow, my math sucks after being out of school for so long. Couldn't even properly keep track of the units.
I will say, Antek claims it can dissipate up to 150W/channel so I have that going for me.
Thanks for the resources, I'll do some reading.
Ultimately, I'll probably just try it as is and see how much rise I get with an actual measurement.
150W on 0.6C/W?
150W x 0.6/W = 90C above ambient. that cooking the transistors.
I believe (although I am still learning about heatsink's myself) if the material is rated at .6 C/W per inch then your 5 inches of heatsink material should be rated at .6/5= .12 C/W.
At 180 watts of dissipation the heatsink will be 180*.12= 21.6 degrees celsius above the ambient Temperature.
This seems to be just about right.
If I am wrong about this please somebody jump in here and correct me on this !!!
I have been scoping out heatsink's for my build and I have been thinking of using some Ximatec CPU coolers.
Newegg.com - XIGMATEK Gaia SD1283 120mm Long Life Bearing CPU Cooler bracket included LGA 2011 i7 i5 775 1155 AMD and dual fan push pull compatible
For $30 this one is rated at .15 C/W at least and is fairly quiet with a fan at 16-24 dba.
XIGMATEK
One of these will allow 333 watts of dissipation at temperature rise of 50 degrees celsius.
It maybe a bit on the warm side with a total heatsink temp. of 75 degrees celsius.
But, It is still below the safe limit for the devices as long as the heat pipe don't explode.
It is not uncommon for these to be run at levels of 200 watts or so.
I am considering about 2 to 4 of these would be good per channel for a Turbo F5 build.
I will mount these to a thick aluminium or copper bar heat spreader to mount the output devices to.
I am anxious to see how your build turns out.
The only thing holding me back right now is were to source the JFET's so I don't end up paying so much for the shipping for just a few pieces.
Keep on DIYin'
jer
no. you don't doble the disipation with doble lenght. if 1 inch give you 0.6C/W you need 4 inches to get down to 0.3C/W. 16 inches to get 0.15C/W and so on.
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They came black anodized. They are not listed individually but if you email John directly, he can send you a quote.
Ah, that makes more sense. So for 5", I'm looking at just under 0.3C/W.
Assuming the above holds, then the 150W x 0.3/W =~ 45C above ambient. That seems to be within the operating parameters. And if I'm only worried about 62W with the F5, then I'm feeling better about things! Should be right around 20C above ambient.
Is that a fair conclusion? Regardless, like I mentioned earlier, I'll build it and measure the temp rise and go from there!
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That 150W rating is for both channels, so 2 x 62W x .3C/W = 37.2C above ambient. Natsink gives about 43C above ambient. Getting pretty warm.
Thanks for running the sim! I'm on a mac so I couldn't run it. The only number that is slightly different from what you had is the total height should be 2.3" or 59mm.
That won't make a material difference, but just for accuracy sake.
Also, just wondering if the ambient air is set at 25 or 40C? It wasn't clear to me in the screen shot. That should be closer to 20C... at least in my house!
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Yes, rerunning the sim with total-height 59mm didn't make a significant difference.
I set the ambient air at 25C.
43C temp rise? Brings the total to 68C, just a bit shy of 150F. That's hot. The heatsinks will feel painful within a second, but won't burn you for a few more.
That's about as hot as you want one of these to run.
In order to keep it at peak thermal efficiency you will need lots of room around the case. Also, you will need a bunch of vent holes in the chassis lid and base to keep the capacitors from cooking. No holes = easy bake oven.
That's about as hot as you want one of these to run.
In order to keep it at peak thermal efficiency you will need lots of room around the case. Also, you will need a bunch of vent holes in the chassis lid and base to keep the capacitors from cooking. No holes = easy bake oven.
Here is the heatsink approach I used for my F5 build. It is nearly silent and runs at below 50C.
http://www.diyaudio.com/forums/pass-labs/121228-f5-power-amplifier-1021.html#post2453420
http://www.diyaudio.com/forums/pass-labs/121228-f5-power-amplifier-1021.html#post2453420
Thanks for the input all! It seems my heat sinks are about the same as the heatsink USA ones that people have used in the past (as for sale here) so I didn't think much of my choice.
But I will think about the tunnel approach as well. Might be doable with my two case idea. Where did you pull the 12V for the fan from?
But I will think about the tunnel approach as well. Might be doable with my two case idea. Where did you pull the 12V for the fan from?
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The fan is powered from one of the 24V power supplies thru a 220 ohm 2W resistor. I think the fan current is 50ma.
BTW: A single HeatSinkUSA E007 heatsink would be fine for a 62W F5 channel without a fan. See the photo in the previous post. http://www.diyaudio.com/forums/pass-labs/121228-f5-power-amplifier-1021.html#post2453420
Exactly my point. My heatsinks are just a tiny bit shorter and a tiny bit wider than those which is why I didn't bother with the calculations before buying them. I figured you all had already done that hard work!
Build the amp as you planned and see how hot it is for real... It's all conjecture so far.
If it runs too hot just blow a small fan on it, you would be amazed what just a little moving air does for the heatsinks.
There are always a bajillion uses for a good case with heatsinks, so you might as well build the case as planned.
If it runs too hot just blow a small fan on it, you would be amazed what just a little moving air does for the heatsinks.
There are always a bajillion uses for a good case with heatsinks, so you might as well build the case as planned.
it will be fine
65W x 0.3 = 19.5C above ambiet. so you have some headroom to crank up the bias to43C temp rise? Brings the total to 68C, just a bit shy of 150F. That's hot. The heatsinks will feel painful within a second, but won't burn you for a few more.
That's about as hot as you want one of these to run.
In order to keep it at peak thermal efficiency you will need lots of room around the case. Also, you will need a bunch of vent holes in the chassis lid and base to keep the capacitors from cooking. No holes = easy bake oven.
He should consider building Zen Mod's "Babysitter"?
Russellc
Populated the boards today. Not 100% sure about the orientation of P1 and P2... Actually was not able to find a photo of this version of the boards all populated. So here's one. Right or wrong.
Question on the thermistors... When you bend them over to the mosfets, how do they stay in contact?
Question on the thermistors... When you bend them over to the mosfets, how do they stay in contact?
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