Hi!
I am buying four heatsinks, two bigger ones and two smaller ones, all of them are 0,6c/W sinks.
These are the bigger ones:
308CL-02500-A-200 - H S MARSTON - HEAT SINK, 0.65°C/W | Farnell Nederland
These are the smaller ones:
94DN-02500-A-200 - H S MARSTON - HEAT SINK, 0.6°C/W | Farnell Nederland
Are the smaller ones suitable for a V2 F5T? one on each side
Are the bigger ones suitable for a F5T V3 monoblock? One on each side.
I had a wild idea about using them all on one chassis and build 2x F5T V2 in the same chassis, so one chassis with 4x50w to biamp my upcoming Elsinores.
But, i am getting more and more interesting in building a pair of F5T V3 monoblocks the more i think about it..
But first i need to build a F5T V2 as i dont have any amp at all now, but i could reuse those boards later on to build a V3, right?
Or should I order 3 pairs of F5T boards direct? Need to know if i can reuse the boards from a built V2 to build a V3, is it possible?
Best regards, Mathias
I am buying four heatsinks, two bigger ones and two smaller ones, all of them are 0,6c/W sinks.
These are the bigger ones:
308CL-02500-A-200 - H S MARSTON - HEAT SINK, 0.65°C/W | Farnell Nederland
These are the smaller ones:
94DN-02500-A-200 - H S MARSTON - HEAT SINK, 0.6°C/W | Farnell Nederland
Are the smaller ones suitable for a V2 F5T? one on each side
Are the bigger ones suitable for a F5T V3 monoblock? One on each side.
I had a wild idea about using them all on one chassis and build 2x F5T V2 in the same chassis, so one chassis with 4x50w to biamp my upcoming Elsinores.
But, i am getting more and more interesting in building a pair of F5T V3 monoblocks the more i think about it..
But first i need to build a F5T V2 as i dont have any amp at all now, but i could reuse those boards later on to build a V3, right?
Or should I order 3 pairs of F5T boards direct? Need to know if i can reuse the boards from a built V2 to build a V3, is it possible?
Best regards, Mathias
that's enough for me , to even not look what's on linked pages
also - that's answer on your questions
8Well if i build a pair of V3 monoblocks, i want them to leave 100w@8ohm in class A.
Will they be sufficient for that much, really? the bigger ones are 150x250x40(WxLxD)
Will they handle that much dissipation as 4 pairs of irfp9240/irfp240 will be used?
Or.. does the the boards in the store have place for 4 pairs of output devices?
Best, regards, Mathias
Will they be sufficient for that much, really? the bigger ones are 150x250x40(WxLxD)
Will they handle that much dissipation as 4 pairs of irfp9240/irfp240 will be used?
Or.. does the the boards in the store have place for 4 pairs of output devices?
Best, regards, Mathias
no matter size/shape
if 'sink is declared as 0.6C/W that means temp rise for 100W of dissipation will be 60C above ambient temp.
so , if you're saying that heatsinks are declared as 0.6C/W , I'm not even looking at web pages and difference in size - it's irrelevant
so - go backwards - take dissipation number of intended amp , calc C/W factor of needed heatsink , to have no more then 25-27C rise above ambient , including losses (say 10% as rule of thumb)
many pages about heatsink choosing
if 'sink is declared as 0.6C/W that means temp rise for 100W of dissipation will be 60C above ambient temp.
so , if you're saying that heatsinks are declared as 0.6C/W , I'm not even looking at web pages and difference in size - it's irrelevant
so - go backwards - take dissipation number of intended amp , calc C/W factor of needed heatsink , to have no more then 25-27C rise above ambient , including losses (say 10% as rule of thumb)
many pages about heatsink choosing
Mathias, do the math. at .6°/W the large sink is suitable for 50 W at 30°C rise. You'll need at least 6 of them for a V3 monoblock at the rails that NP used in the article. If you want to go for 100W in class A, figure on bit more than that.
An F5TV3 requires 2 sets of store boards to have 8 output devices (4 pair). To help visualize the heatsink requirements, the 5U store enclosure is about as small as you want to go for a V3 monoblock as described in the article. High power requires bigger heat sinks...
An F5TV3 requires 2 sets of store boards to have 8 output devices (4 pair). To help visualize the heatsink requirements, the 5U store enclosure is about as small as you want to go for a V3 monoblock as described in the article. High power requires bigger heat sinks...
For a v3 I would look for those heatsinks with 80+ mm long fins!!! 200x400x80 with at least 15mm baseplate thickness! But the elsinores dont really need that much power, they are efficient speakers and 25w should give you painful spl levels!!!
you know that one ch of V3 has the same dissipation as 2 ch V2?
15mm baseplate with 200*400mm surface is not needed. 10mm is plenty.
AudioSan, 1 of the bigger ones should be enough for 1 ch V2, 3 of them is just insane..
I got an idea, if I build V3 monoblocks, I could use 4 of the smaller ones, which is 123w*250l*40h to build a tunnel where a 120mm fan will fit quite nicely.
Does anyone have a link to a site where I can calculate how much more efficient the sinks become with regard to increase and decrease in M3/H air flow?
4*0,6C/W sinks with a fan that is variable should be able to cope with quite much dissipation, right?
I got an idea, if I build V3 monoblocks, I could use 4 of the smaller ones, which is 123w*250l*40h to build a tunnel where a 120mm fan will fit quite nicely.
Does anyone have a link to a site where I can calculate how much more efficient the sinks become with regard to increase and decrease in M3/H air flow?
4*0,6C/W sinks with a fan that is variable should be able to cope with quite much dissipation, right?
that is not insane. its normal. after all. 1 ch of V2 have over 120W of dissipation.
with a temp rise of 25c above ambient (wich is normal) you get:
25/120=0.208C/W pr ch. so even 3 of them is marginal.
with a temp rise of 25c above ambient (wich is normal) you get:
25/120=0.208C/W pr ch. so even 3 of them is marginal.
But, how come Zen mod writes they are capable of handling it?
My ambient is 20c, and the sinks could, atleast fir me be allowed to reach 65-70c as the top lid will have plenty of ventilation holes in it.
Either are you wrong, or Zen Mod. Don't mean to offend anyone, I am just not up to the task of understanding this at this moment.. Are your equation or this equation just as simple as that?
My ambient is 20c, and the sinks could, atleast fir me be allowed to reach 65-70c as the top lid will have plenty of ventilation holes in it.
Either are you wrong, or Zen Mod. Don't mean to offend anyone, I am just not up to the task of understanding this at this moment.. Are your equation or this equation just as simple as that?
what Zen ment by "that's enough for me , to even not look what's on linked pages"
is refered to "all of them are 0,6c/W sinks". he did not need to look more at them when they are declared as 0.6C/W sinks. it is no way they can handle it.
even if your ambient is steady at 20C. and you alowed the sinks to get 70C(wich is way to high) that is 50C above ambient.
50/120=0.41C/W.
that 0.6C/W sinks will be 70C above ambient. and that will result in fried output fet's.
is refered to "all of them are 0,6c/W sinks". he did not need to look more at them when they are declared as 0.6C/W sinks. it is no way they can handle it.
even if your ambient is steady at 20C. and you alowed the sinks to get 70C(wich is way to high) that is 50C above ambient.
50/120=0.41C/W.
that 0.6C/W sinks will be 70C above ambient. and that will result in fried output fet's.
Last edited:
- Status
- Not open for further replies.