Thanks for the nice comments. (Especially Choky
)
Paul, the heatsinks used on the finished amp was a pair I traded for some other things. A friend of mine got his hands on 4 of those. They used to sit in some electrical facility. Only drawback with those is the weight, the amp is a pain to handle.
The nice golden ones I had at work. One of the engineers knowing about my amp building, came one day and told me that they had just thrown out a bunch of PSU's for some welding gear.
I could just take a look in the container and take whetever I wanted
How lucky can one get? I had 8 of those nice golden heatsinks for free that day I gave 2 of them to a friend, so that leaves me with 6 pcs. The other 4 are a little smaller than the ones on the picture. They would make a really nice set of dualmono chassis perfect for a pair of Aleph-J's.
So I am afraid I can't tell you where to buy them.
Steen
)Paul, the heatsinks used on the finished amp was a pair I traded for some other things. A friend of mine got his hands on 4 of those. They used to sit in some electrical facility. Only drawback with those is the weight, the amp is a pain to handle.
The nice golden ones I had at work. One of the engineers knowing about my amp building, came one day and told me that they had just thrown out a bunch of PSU's for some welding gear.
I could just take a look in the container and take whetever I wanted
How lucky can one get? I had 8 of those nice golden heatsinks for free that day I gave 2 of them to a friend, so that leaves me with 6 pcs. The other 4 are a little smaller than the ones on the picture. They would make a really nice set of dualmono chassis perfect for a pair of Aleph-J's.So I am afraid I can't tell you where to buy them.
Steen
Thanks Graeme. Yes the finished amp on the picture started out as the F2, but I was pretty keen to listen to a J-fet poweramp so I "borrowed" the chassis and the psu from my F2 clone and installed the Zen 8 boards in it. Couldnt wait till the other chassis was done
Right now it is a ZenV8/9 crossbreed.Steen
Ok looking at Steen's heat sinks, they look like over kill. Now I am trying to figure out the .25 CW thing in the Z9 write up, but an understanding has not come to me yet. Any one got a simple explaination?
Now I may want it way too easy, but could someone post a length, width, height of a workable heat sink or are the vaiables too complex. Or how about a manufacture and their part no.?
The last amp I built goes back to heathkits in the late 60's, but I would like to give the Z9 a try.
Thanks for any help given.
Now I may want it way too easy, but could someone post a length, width, height of a workable heat sink or are the vaiables too complex. Or how about a manufacture and their part no.?
The last amp I built goes back to heathkits in the late 60's, but I would like to give the Z9 a try.
Thanks for any help given.
... Steen's heatsinks look to be about right to me.
ZEN amps run HOT
The more heat you can dissipate the better.
I've read people were happy with product they got from
Conrad Heatsinks
We had a group buy a few years a go for some really nice R-Theta
heatsinks that measure 11"x11" and had 2" fins. I have a couple more
of these... when they're used up i'm going to try Conrad myself.
Or, you can always browse eBay.
...bottom line, the bigger the better when it comes to Class A heatsinks.
ZEN amps run HOT
The more heat you can dissipate the better.
I've read people were happy with product they got from
Conrad Heatsinks
We had a group buy a few years a go for some really nice R-Theta
heatsinks that measure 11"x11" and had 2" fins. I have a couple more
of these... when they're used up i'm going to try Conrad myself.
Or, you can always browse eBay.
...bottom line, the bigger the better when it comes to Class A heatsinks.
That is right, indeed
The heatsinks on the finished amp weigh about 9kg, thats over 18 lbs a piece. When the amp has been turned on the whole evening, it is just steaming out heat. Heatsinks can only be too small, I have never heard of a heatsink too big
Bottomline is: get the biggest one available.
Steen
bluemartini said:
Here's my understanding (someone please tell me if I got it wrong):
The 0.25 C/W is the celcius degrees of temperature rise above ambient per watt. So, a heatsink with this rating will rise 25 degrees C when dissapating 100 watts. Converting to degrees F and typical room temperature, this ends up being about 147 degrees F - pretty hot, but manageable.
So, let's take the largest standard Conrad heatsink (I'm strongly considering these, btw) - the MF35-151.5. This is rated at 0.21 C/W for a 80 degree C rise. Conrad points out that the sinks are less efficient at lower rise values. They indicate a correction factor of 1.45 or so for a 25 degree rise. So, this sink has a (0.21 x 1.45 =) 0.3045 C/W for a 25 degree rise. So, 100 watts will rise about 30 degrees or to keep it under 25 degrees means only 82 watts can be dissapated. So, one of these per channel may be too little.
Does that help?
I may choose to use two sinks per channel in a monoblock configuration. I like the idea of the flanged sinks, so I may go with two MF30-2F-151.5s per channel. I figure that ought to be enough. Not cheap going that route, however.
Paul Ebert
Moe29, thanks for the conrad site. That helped,
Blue, I get the point looking at passdiy, everyone uses big iron as Steen said nothing small. over kill is the way to go. Maybe I can heat my basement listening room this way and enjoy the music.
Paul. Thats for your explaination. I get it now. Your relating the devices back to the output and the c/w factor now makes sense to me. Your explanation was expressed as a formula will help me and others in the future.
Thanks to all
One last question. Is there not a DIY supplier in the USA that can supply heat sinks of this size. My limited search did not turn one up quickly.
Blue, I get the point looking at passdiy, everyone uses big iron as Steen said nothing small. over kill is the way to go. Maybe I can heat my basement listening room this way and enjoy the music.
Paul. Thats for your explaination. I get it now. Your relating the devices back to the output and the c/w factor now makes sense to me. Your explanation was expressed as a formula will help me and others in the future.
Thanks to all
One last question. Is there not a DIY supplier in the USA that can supply heat sinks of this size. My limited search did not turn one up quickly.
Thanks Choky for the surplus site, I picked up two sets of the tunnel heatsinks today. They are not as large as the 11 x 11 x 2 that Moe29 indicated were the group buy, but if I use one pair on a monoblock, which Paul suggested in his post about the largest from Conrad, I think I will be ok.
The heat sinks are 12.5 x 4.75 x 2.375 inchs as I recall. The watts disapation are unknown as is the C/W factor, but the total size seems reasonable.
let me know if I am wrong
Again thanks for the help
The heat sinks are 12.5 x 4.75 x 2.375 inchs as I recall. The watts disapation are unknown as is the C/W factor, but the total size seems reasonable.
let me know if I am wrong
Again thanks for the help
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