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Old 30th June 2005, 03:15 PM   #91
Mark Kravchenko --- www.kravchenko-audio.com
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Default Good on one side bad on the other

The TF package is much more limited in it's ability to dissiapte heat. As such it can't be pushed as hard as the T package. There are good junction temperature curves in the data sheet.

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Old 30th June 2005, 03:20 PM   #92
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When you add a good insulator/isolator (which you will almost always need) to the T package's heat dissipation is comparable to if not worse than the TF package. But if you really want it, maybe Brian will accomodate you.
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Old 30th June 2005, 03:41 PM   #93
Mark Kravchenko --- www.kravchenko-audio.com
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Default Point Taken

You are correct Russ.

THere are differences in the curves to suggest that the full pack version does warm up faster and cool off slower even with an almost the same thermal transfer number. The note to read is the derating factor if I remember right.

THere is only going to be some difficulty if the heatsink is on the small side and the amp is driven hard with a power supply voltage nering the max. Keep to around 30 volts after rectification or after the regulator and you will be just fine.

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Old 30th June 2005, 05:21 PM   #94
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I think the schematic for this version of the amp specified 24VAC, which results in 33.6VDC for the rails.

Speaking of heatsinks, would anyone be interested in including them in the kit? Here's what I was thinking:
http://cgi.ebay.com/ws/eBayISAPI.dll...sPageName=WDVW

Have him cut 3" pieces. One piece for each amp (3 x 5 3/8 inches). 3" would be $4.38 each, plus shipping charges out course. Could go to 4" for $5.84 each.
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Old 30th June 2005, 05:25 PM   #95
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Quote:
Originally posted by BrianDonegan
I think the schematic for this version of the amp specified 24VAC, which results in 33.6VDC for the rails.

Speaking of heatsinks, would anyone be interested in including them in the kit? Here's what I was thinking:
http://cgi.ebay.com/ws/eBayISAPI.dll...sPageName=WDVW

Have him cut 3" pieces. One piece for each amp (3 x 5 3/8 inches). 3" would be $4.38 each, plus shipping charges out course. Could go to 4" for $5.84 each.

That sound like a great idea! If 4" can dissipate enough heat I would be in for that.
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Old 30th June 2005, 07:56 PM   #96
Gmorris is offline Gmorris  United States
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Would anyone be interested in these heatsinks?

I'll most likely be using the sinks on the left (cut to size) for this project. I have some extras I'm trying to get $15/pair for....or maybe trade towards the kit?
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Old 30th June 2005, 09:04 PM   #97
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Default 3" or 4"

I am in for either 3" or 4".
Probably 3" will do.

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Old 1st July 2005, 01:40 AM   #98
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Anyone else want to offer an opinion of heatsink size/have interest in them? I can add it to the Wiki and consider it seperate from the main kit.
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Old 1st July 2005, 01:48 AM   #99
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Wiki updated with heatsink information and added to the grid. Just testing interest for now.
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Old 1st July 2005, 09:46 AM   #100
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Any informations:

I have found any numerations not correct on the BOM and have corrected it ( only the serigraphy references, the quantities are correct ).I attach the corrected version to verify. I Creed that you did a good work, Brian.

LM3886 T now TF: The T version ( not iso ) has theoretically a better ability of dissipate of the heat ( internal ) toward the heatsink. In my LM3886 circuit it has to dissipate " theoretically " a lot of energy if the load is 4 ohms. This calculations however I am in " sinusoidal continues power" that doesn't exist in the ordinary music. I have done my test with the "T" type (not iso), but I believe that for an "moderate" use goes well the TF type ( iso ) for the reasons lists from Russ...

Heatsink: I Suggestion to use a type with 1-1.2 C/W of Thermal Resistance, with vertical development ( like NS- AN1192 by BR100 mod. )

Ciao

Mauro
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