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Old 13th April 2005, 11:37 PM   #11
BillyM is offline BillyM  United States
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BWRX, dont doubt Arctic Silver's components, they are really top-notch. I ordered a set of the same stuff Todd linked to and plan to do the same as soon as my new boards get in. I'll have pictures as soon as Efunctional.com gets on the freakin ball...

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-BillyM
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Old 14th April 2005, 12:20 AM   #12
BWRX is offline BWRX  United States
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i don't doubt their thermal paste or adhesive, i'm sure it's just as good or better than others. i'm just saying that it literally doesn't have nearly as good thermal conductivity as solder does. on arctic silver's site it says their arctic alumina thermal compound has a thermal conductivity of >4W/m*K. well regular old 60/40 solder has a thermal conductivity of around 57W/m*K, making it a much better conductor of heat. it's probably cheaper than that thermal paste too, that's why tripath says the solder slug is a must to increase the little chip's ability to dissipate power, and also why it has me that SI said the solder slug wasn't necessary when i've already driven the amp hard enough to go into thermal protection.
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Old 14th April 2005, 12:47 AM   #13
Pano is offline Pano  United States
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I have a slugless version too.
S/N: AIV0502003068.

This is not good. The chip needs the cooling.
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Old 14th April 2005, 01:34 AM   #14
amt is offline amt  United States
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Well, thats not good...

I dont know the exact reason for the change, but it was said to not be needed. I didnt get the specifics as to R&D etc, but they are sticking with this as far as I know.

I took a good look at the chip and its raised off the board just enough so that I could slip a piece of aluminum under it.

Dont laugh, but maybe this could be a solution of sorts. I will give it a try tonight and see what happens. Its a strip of a coke can and it fits tightly between the bottom of the chip and the board.

amt
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Old 14th April 2005, 02:20 AM   #15
toddsts is offline toddsts  United States
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Quote:
Originally posted by BWRX
on arctic silver's site it says their arctic alumina thermal compound has a thermal conductivity of >4W/m*K. well regular old 60/40 solder has a thermal conductivity of around 57W/m*K,
Wow, I didn't realize it was that much worse than solder. But it should still be better than air and won't have the electrical conductance worries of solder, right?

Todd
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Old 14th April 2005, 02:34 AM   #16
BWRX is offline BWRX  United States
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todd, yes - air has a much lower thermal conductivity that depends on the ambient temperature and the humidity. googling "thermal conductivity of air" led me to a study that says air at 20 degC and 20% humidity is about 0.026W/m*K.

amt, i laughed but also think that's a pretty clever idea! that's "junkyard engineering" at its finest
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Old 15th April 2005, 04:35 AM   #17
KT is offline KT  United States
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OK, so what are D1, D2, D3, and D4? I don't have those on my board. Are they necessary for good sonics/ proper funtioning? On my (I believe) version 2 board, those areas are covered with the solder slug.

It's interesting that SI changed their whole solder slug approach. At this price point, they probably don't worry about squeezing the best out of the litle amp, not when they can save a good deal by skipping all the solder. Please keep us posted on any performance differences you find.

Best,
KT
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Old 15th April 2005, 10:06 AM   #18
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Quote:
Originally posted by KT
OK, so what are D1, D2, D3, and D4? I don't have those on my board. Are they necessary for good sonics/ proper funtioning? On my (I believe) version 2 board, those areas are covered with the solder slug.

It's interesting that SI changed their whole solder slug approach. At this price point, they probably don't worry about squeezing the best out of the litle amp, not when they can save a good deal by skipping all the solder. Please keep us posted on any performance differences you find.

Best,
KT

Tripath lists them as needed. The early SI's did not have them. The pupose is to prevent back emf coming back from the speaker. This CAN drive the output to below zero.
There are lots of SI out there without them. Never heard that just playing music blew one up. Usually it is hooking up a new power supply, or a modifing the circuit boards. Lots have gone up in smoke after being modified.

George
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Old 15th April 2005, 09:15 PM   #19
amt is offline amt  United States
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Well Ive run the new board without a case and in the stock case and it does get fairly hot. Im using 96db 8ohm speakers and after several hours of continuous use, Ive yet to trip the thermal switch. But I will admit that at comfortable listening levels, Im probably keeping it within the 5watt range.

My guess at this point is that SI has "de-rated" his amp so as to make it a little less home hifi friendly. Bet the next generation version thats $120 has heatsinking.

Im now playing with a heatsink concept that attaches to both sides of the chip via the slug taps that are visible on each side. The sink will contact them and route over the top of the chip. An upside-down U. It will probably use a screw, running from each side to clamp the sink to the tabs. I checked the amount of heat being dissipated though the plastic case versus the bottom side, where the slug is and Im not sure that its worth mounting a heatsink on it. Pulling heat from the slug is the key to cooling this chip.

amt
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Old 16th April 2005, 01:33 AM   #20
Pano is offline Pano  United States
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That's the nice thing about the TA2021B chip. It has the heat slug at the top, where you can get to it.
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