Tinitus,
Thank you for your second thoughts.
I thought the $10 donation was a bit steep, but I respect your judgment and I really want to build this Amp the best I can the first time. You were generous enough to offer to help me out with my request, so I did not want to be rude and question you. I can take a pun and a polk just fine, seems I was correct in my assessment of your character.
Having recently been the sponsor of a GB I know that they can be costly to the one who runs the GB. At some point in time we all have the opportunity to repay the kindness shown by our brethren here on DiyAudio.
Send me a PM and we'll talk $$$ again. Did you call me DAFT??? LOL..
Ron
Thank you for your second thoughts.
I thought the $10 donation was a bit steep, but I respect your judgment and I really want to build this Amp the best I can the first time. You were generous enough to offer to help me out with my request, so I did not want to be rude and question you. I can take a pun and a polk just fine, seems I was correct in my assessment of your character. Having recently been the sponsor of a GB I know that they can be costly to the one who runs the GB. At some point in time we all have the opportunity to repay the kindness shown by our brethren here on DiyAudio.
Send me a PM and we'll talk $$$ again. Did you call me DAFT??? LOL..
Ron
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Oh please, I said its pretty daft that you should donate Marc 10USD to get only 4 isolators
I meant that it was pretty daft of ME to demand what I did
I thought that was 100% clear
But it clearly shows how easy things can go wrong
Even when we try to do it right
I payed 27USD for 30 pieces
Plus 10USD donation to Marc(losses)
That makes 1.25USD/ea
Plus 1.75USD, shipping to you
Total cost is 6.75USD
I want you to donate the money to the Forum
But I suggest you wait until isolators arrive
Please correct if my calculation seems wrong, in any way
cheers
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Oh please,
I meant that it was pretty daft of ME to demand what I did
I thought that was 100% clear
It was 100% clear, hence the "LOL" comment
But it clearly shows how easy things can go wrong
Even when we try to do it right
Yep, sometimes it's hard to tell when we are joking
I payed 27USD for 30 pieces
Plus 10USD donation to Marc(losses)
That makes 1.25USD/ea
Plus 1.75USD, shipping to you
Total cost is 6.75USD
How about I donate the $10 to US? (DiyAudio.com)? Makes me happy, everybody wins!
I want you to donate the money to the Forum
But I suggest you wait until isolators arrive
Please correct if my calculation seems wrong, in any way
cheers
Thanks Tinitus,
Ron
Question for anyone that is using these insulators
I am considering buying a small sheet of this product to cut into insulators as needed, but I have a few questions for the users on this group buy.
Has anyone tested the product to see if it is actually performing better than mica and grease or other insulators?
How workable it are the insulators? Are they too fragile to cut with an exacto knife?
Any insight would be greatly appreciated.
Nick
I am considering buying a small sheet of this product to cut into insulators as needed, but I have a few questions for the users on this group buy.
Has anyone tested the product to see if it is actually performing better than mica and grease or other insulators?
How workable it are the insulators? Are they too fragile to cut with an exacto knife?
Any insight would be greatly appreciated.
Nick
Nick:
Good questions. I've compared them favorably with the best performing Bergquist pads available at Digikey. I'm not sure if tab temperature is the best metric, but that's what I used. I'd be interested to see if there is another way to compare them, without drilling holes for a thermocouple. I have recently ordered a IR thermometer and plan on comparing with that as well, once it arrives.
I would say they are a bit more fragile than other insulators. The main thing to worry about is torquing the device down too hard. Cutting with an exacto knife is possible, but you have to be careful with the fiberglass pieces that run through the pad. I'd suggest clamping the piece down with say a piece of aluminum and exposing the edge you wish to cut. The clamping force will help prevent pulling on the fiberglass strips, which is what causes the pad to tear in my experience.
I have a few pieces handy that have manufacturer defects that I'd be glad to pop in the mail for you, just shoot me your information and I'll try and locate them among the various piles of stuff in my work room
Thanks for the info. I would would definitely be interested in your findings when your IR arrives. What temp. difference are you measuring between tab and heatsink?
Measuring tab temps. I recorded 30c difference with silica on a high biased F5 pass clone and 22c difference on the same amp with mica. I would really like to drop that number further.
If I commit to my purchase then the defects would be great, especially to practice cutting on a few pieces before touching a virgin sheet.
Measuring tab temps. I recorded 30c difference with silica on a high biased F5 pass clone and 22c difference on the same amp with mica. I would really like to drop that number further.
If I commit to my purchase then the defects would be great, especially to practice cutting on a few pieces before touching a virgin sheet.
I might be offering these Keratherm to everyone.
Price will be close to the price here (at least for TO-247), provided you get at least 50 pcs.
For TO-220, there is two type:
one is the type here: 18mm x 12mm
another is: 19mm x 14mm
FYI, a typical TO-220 chip is 15x10, so the bigger one offers 2mm per edge, which might be very useful if you use non-insulating thermal grease like arctic silver
The difference of cost is about 5-10 cents.
For TO-247 I think the 32x23 size here is very good and I will stick to it.
For uncut sheet, there is a 34mm x 27mm square sheet without any hole, which is plenty to cover any common package.
I think pads without hole will be good for clip mounting (rather than screw mounting), especially if you want to use conductive thermal grease.
Due to the lower volume I expect, and the larger size, the cost is expected to be between 150%-200% that of the 32x23 TO-247.
Let me know which TO-220 size you prefer, and what do you think about the 34x27 sheet without hole.
Price will be close to the price here (at least for TO-247), provided you get at least 50 pcs.
For TO-220, there is two type:
one is the type here: 18mm x 12mm
another is: 19mm x 14mm
FYI, a typical TO-220 chip is 15x10, so the bigger one offers 2mm per edge, which might be very useful if you use non-insulating thermal grease like arctic silver
The difference of cost is about 5-10 cents.
For TO-247 I think the 32x23 size here is very good and I will stick to it.
For uncut sheet, there is a 34mm x 27mm square sheet without any hole, which is plenty to cover any common package.
I think pads without hole will be good for clip mounting (rather than screw mounting), especially if you want to use conductive thermal grease.
Due to the lower volume I expect, and the larger size, the cost is expected to be between 150%-200% that of the 32x23 TO-247.
Let me know which TO-220 size you prefer, and what do you think about the 34x27 sheet without hole.
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If this keratherm works as promised, I would expect it to loose its advantage if you use thermal grease
non-insulating arctic silver ?
sounds dangerous to me
could it make short connection through the hole at mounting screw ?
But I would still be interested in raw uncut sheets, in a size that fits into an envelope
But not an option, I suppose
You miss the point completely. The stuff requires NO grease, just like Silpad.
But unlike Silpad, or mica with Whatever grease, it has a maximum temperature difference of 5°C at 30W dissipation on a TO247/TO3P.
I have been using the stuff for years (since 2006), have measured enough examples in enough different applications myself.
I am also the one who made it know to the Pass forum.
So the stuff works, as long as you use it properly, like NO grease.
See :
http://www.diyaudio.com/forums/pass-labs/37262-mica-goop-2.html#post1032023
Even the fragility of the foil is public since 2006 !!
Patrick
PS You can get A4 sized uncut sheets (which is what I use) if you buy enough. But you need ceramic scissors to cut them properly. Or at least use a brand new one which will be no good for anything else after finishing one A4 sheet. The foil is ceramic powders embedded in plastic matrix.
But unlike Silpad, or mica with Whatever grease, it has a maximum temperature difference of 5°C at 30W dissipation on a TO247/TO3P.
I have been using the stuff for years (since 2006), have measured enough examples in enough different applications myself.
I am also the one who made it know to the Pass forum.
So the stuff works, as long as you use it properly, like NO grease.
See :
http://www.diyaudio.com/forums/pass-labs/37262-mica-goop-2.html#post1032023
Even the fragility of the foil is public since 2006 !!
Patrick
PS You can get A4 sized uncut sheets (which is what I use) if you buy enough. But you need ceramic scissors to cut them properly. Or at least use a brand new one which will be no good for anything else after finishing one A4 sheet. The foil is ceramic powders embedded in plastic matrix.
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I should expect that you, as a respectable gentleman, would get some samples of the stuff, try it out, understand the function and the performance, before you would open a new thread to offer it to fellow DIYers, just like Marc did here (irrespective of motivation).
Best regards,
Patrick
Best regards,
Patrick
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As already mentioned in August 2007 :
http://www.diyaudio.com/forums/pass-labs/37262-mica-goop-3.html#post1289329
WÄRMELEITFOL.86/82 ROT 190X190X0,25 MM im Conrad Online Shop
for those who lives in continental Europe and wish to experiment.
Plus a whole variety of others :
http://www.conrad.de/ce/de/FastSearch.html?search=kerafol&x=0&y=0&=Schnellsuche&initial=true
and you do not need to buy 1000 pieces if you only want one.
Patrick
http://www.diyaudio.com/forums/pass-labs/37262-mica-goop-3.html#post1289329
WÄRMELEITFOL.86/82 ROT 190X190X0,25 MM im Conrad Online Shop
for those who lives in continental Europe and wish to experiment.
Plus a whole variety of others :
http://www.conrad.de/ce/de/FastSearch.html?search=kerafol&x=0&y=0&=Schnellsuche&initial=true
and you do not need to buy 1000 pieces if you only want one.
Patrick
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Thank you Patrick again for your kind suggestions and the direct links!
I spend most of the time looking at various datasheets, and I admit I had yet to have a physically look at one of these.
I was assuming that since many here is using it (though the fragility), and the datasheet figure and user report all confirms the excellent thermal property, this produce should be rather good for our purpose.
I'm on my way to get some TO-247 transistors for sale, and wants to offer these isolation pad to provide some convenience for my future buyers, as I myself find it hard to get a small quantity of high performance isolation pad in a cost effective and easy way at where I live. So I do need a large quantity of these.
I fully agree with you that Marc had done an excellent service here which is beyond what an average person would, myself included for sure.
Zhou Fang
I spend most of the time looking at various datasheets, and I admit I had yet to have a physically look at one of these.
I was assuming that since many here is using it (though the fragility), and the datasheet figure and user report all confirms the excellent thermal property, this produce should be rather good for our purpose.
I'm on my way to get some TO-247 transistors for sale, and wants to offer these isolation pad to provide some convenience for my future buyers, as I myself find it hard to get a small quantity of high performance isolation pad in a cost effective and easy way at where I live. So I do need a large quantity of these.
I fully agree with you that Marc had done an excellent service here which is beyond what an average person would, myself included for sure.
Zhou Fang
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