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Old 23rd September 2012, 02:27 AM   #421
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yes you can. there is almost no heat. the point is to let the diodes have the same temp.
but if you run a low bias. then you might be better off running your diodes on the main sink. as they then will start conducting at a earlier point.
you even might be best off not to heatsink them at all

Last edited by AudioSan; 23rd September 2012 at 02:30 AM.
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Old 23rd September 2012, 02:32 AM   #422
Rush is offline Rush  United States
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We should ask Heatsink USA what aluminum they used, so the proper weld rod can be chosen.

Rush
I did ask Heatsink USA what aluminum they use: 6063 alloy, with either a T5 or T6 temper depending on profile. This is a very easy aluminum to weld. Of course this doesn't spread the heat, but does thermally connect the heatsinks and makes them one. Just avoid putting a devise on the welded area.

While you have the welder out, weld a heat spreader on the two heatsinks. With a continuos weld along the edge of a 3/8" or 1/2" aluminum bar 2" wide or so the full length of the heatsink. The weld would give the maximum heat transfer, far better than thermal grease if the bar was only about 2" wide.
At least I think it would be better than thermal grease. I haven't run any numbers, just thinking out loud.

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Old 23rd September 2012, 02:40 AM   #423
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well. all this realy depends on the weld/welder. and there is NO turning back.
so i will NOT recomend doing this. if you are a expert welder. go ahead. but don't let a welder that do not know about electronics/heattransfer do the job. it can cost you alot.
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Old 23rd September 2012, 02:41 AM   #424
anilva is offline anilva  India
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Originally Posted by AudioSan View Post
yes you can. there is almost no heat. the point is to let the diodes have the same temp.
but if you run a low bias. then you might be better off running your diodes on the main sink. as they then will start conducting at a earlier point.
you even might be best off not to heatsink them at all
I have got some solid heatsinks. Want to push the F5T V2 to it's limit in terms of the bias and see where the '5 secs touch test' happens. Have a 1000VA toroid for stereo and 8 X 10000 uF per channel.
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Old 23rd September 2012, 02:46 AM   #425
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I have got some solid heatsinks. Want to push the F5T V2 to it's limit in terms of the bias and see where the '5 secs touch test' happens. Have a 1000VA toroid for stereo and 8 X 10000 uF per channel.
so you are thinking of a stereo V2 with commen trafo?
do the adjusments nice and easy. and let it worm while you monitor it.
what sec voltage are we looking at on this transformer?
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Old 23rd September 2012, 03:01 AM   #426
anilva is offline anilva  India
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so you are thinking of a stereo V2 with commen trafo?
do the adjusments nice and easy. and let it worm while you monitor it.
what sec voltage are we looking at on this transformer?
Yes, Stereo. 24V at each secondary wiinding.
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Old 23rd September 2012, 03:09 AM   #427
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okei thats about +/-30V rails.
at max 2A bias. tou will want to stay below that. (the diodes start conducting at 1A when they are cold i think)
thats 2A. 4Apeak^x8ohm=128W peak/2=64W classA at 8ohm.
dissipation is 2Ax30Vx2=120W pr ch.

Last edited by AudioSan; 23rd September 2012 at 03:14 AM.
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Old 23rd September 2012, 09:15 AM   #428
AndrewT is offline AndrewT  Scotland
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Originally Posted by AudioSan View Post
okei thats about +/-30V rails.
at max 2A bias. tou will want to stay below that. (the diodes start conducting at 1A when they are cold i think)
thats 2A. 4Apeak^x8ohm=128W peak/2=64W classA at 8ohm.
dissipation is 2Ax30Vx2=120W pr ch.
those numbers must be wrong.
You can't get 64W of ClassA when dissipation is only 120W !
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Old 23rd September 2012, 09:33 AM   #429
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Quote:
Originally Posted by AudioSan View Post
okei thats about +/-30V rails.
at max 2A bias. tou will want to stay below that. (the diodes start conducting at 1A when they are cold i think)
thats 2A. 4Apeak^x8ohm=128W peak/2=64W classA at 8ohm.
dissipation is 2Ax30Vx2=120W pr ch.

Power is voltage limited to less than 50w
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Old 23rd September 2012, 10:58 AM   #430
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yes of course
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