Jump to content

Recommended Posts

Posted (edited)

Beware.. those razors are pure evil Colin.

I think I must have removed enough of my face over time to give someone a decent sized skin graft due to that thing. It was my first razor in '75

Edited by Smeggy
Posted

I tried emailing and posting in that thread, but my account is still under moderation. Hopefully my posts get approved and he emails me.

Posted (edited)
I tried emailing and posting in that thread, but my account is still under moderation. Hopefully my posts get approved and he emails me.

it may take a while to get through to the seller. I think you could use the F5 boards I sold you, but try and get the devices as far as possible apart, or look into using heat spreaders to make sure you are using the depth of the heat sink to its maximal potential. Also, consider looking at the more exotic isolator materials, as I'm finding these to be an excellent performance increase. As long as you're not absolutely set on hitting the bias used in the First Watt, I think you'll be okay. If you actually going to do the math instead of a simple "hand test" after the fact, remember you have to derate the Conrad heat sinks as the C/W is quoted at a much higher ambient temperature than you want to run your devices at (80 C). One you start to really look at the numbers, (and appropriate implications due to the fact that powder coating doesn't perform as well as anodizing) these IMHO are not optimal for use in a power amplifier. But given the caveats above, you should be okay.

edit: The R-Theta GB (which is ending soon, as is under the title Aavid Thermalloy), IMHO would be a better choice for a F5.

Edited by luvdunhill
Posted
hrm, I'll look, thanks marc

Here's the really counter intuitive thing I've found. Two 6" x 6" heat sinks perform better than one 6" x 12" heat sink (assuming same type, and for argument's sake there is a single output device in the center of each 6"x6" and spaced out similarly for the 6"x12" heat sinks), even when strapped together like proposed in that GB.

Posted

GS-1 got himself a little buddy. :)

3471187345_962b6903f5.jpg

The SR-003 are a slightly strange sensation on the head and I'm still playing around with the fit, but they certainly sound good. I was expecting the bass to be much less punchy than it actually is! :)

Posted
GS-1 got himself a little buddy. :)

3471187345_962b6903f5.jpg

The SR-003 are a slightly strange sensation on the head and I'm still playing around with the fit, but they certainly sound good. I was expecting the bass to be much less punchy than it actually is! :)

How's the Scotch?

Posted
it may take a while to get through to the seller. I think you could use the F5 boards I sold you, but try and get the devices as far as possible apart, or look into using heat spreaders to make sure you are using the depth of the heat sink to its maximal potential. Also, consider looking at the more exotic isolator materials, as I'm finding these to be an excellent performance increase. As long as you're not absolutely set on hitting the bias used in the First Watt, I think you'll be okay. If you actually going to do the math instead of a simple "hand test" after the fact, remember you have to derate the Conrad heat sinks as the C/W is quoted at a much higher ambient temperature than you want to run your devices at (80 C). One you start to really look at the numbers, (and appropriate implications due to the fact that powder coating doesn't perform as well as anodizing) these IMHO are not optimal for use in a power amplifier. But given the caveats above, you should be okay.

edit: The R-Theta GB (which is ending soon, as is under the title Aavid Thermalloy), IMHO would be a better choice for a F5.

What exotic isolator materials have you tried out? I was looking at using thin kapton film in conjunction with a heat spreader. Also, what kind of test rig have you used for your measurements? I would like to do some testing to verify my ideas.

Posted
What exotic isolator materials have you tried out? I was looking at using thin kapton film in conjunction with a heat spreader. Also, what kind of test rig have you used for your measurements? I would like to do some testing to verify my ideas.

you mean the non-cancer causing ones? :) Quite a few actually.

You have to be very careful using Kapton film. How thin are you considering going? Remember, now you have three thermal junctions as you need interface material on both sides of the Kapton. Also, look at the thermal conductivity of Kapton, not just its thermal resistance. In this comparison, Kapton performs pretty marginally. You can help things out by going thinner, but once you look at how thin you must go, it begins to be a non-option. Just as an example, compare AL2O3 pads to Kapton and you'll see what I mean.

Just drill a hole at an angle under the device and use a thermocouple. That's the most accurate I've found.

Posted
What exotic isolator materials have you tried out? I was looking at using thin kapton film in conjunction with a heat spreader. Also, what kind of test rig have you used for your measurements? I would like to do some testing to verify my ideas.

you mean the non-cancer causing ones? :) Quite a few actually.

You have to be very careful using Kapton film. How thin are you considering going? Remember, now you have three thermal junctions as you need interface material on both sides of the Kapton (edit: depends if you consider Kapton rigid, like mica. I do.). Also, look at the thermal conductivity of Kapton, not just its thermal resistance. In this comparison, Kapton performs pretty marginally. You can help things out by going thinner, but once you look at how thin you must go, it begins to be a non-option. Just as an example, compare AL2O3 pads to Kapton and you'll see what I mean.

Just drill a hole at an angle under the device and use a thermocouple. That's the most accurate I've found.

Posted
See you there ;)

Indeed you will.

Got fairly lucky on the timing, ended up only costing $250 for everything. Flying out of BWI on US Air at 6:10am Wednesday, connections in Vegas, then onward to arrive at SFO at 11am. Return leg is nonstop on Airtran, leaving LAX at 11:30pm Sunday, arriving at BWI around 7:30am the next day.

Posted
Colin, the Hilton will provide free shuttle to the Airport on Sunday just make sure you reserve a seat with them.

Good to know, will that still be running at 11:30? Where do I sign up? Also, can I make use of that considering I wont have a room reserved in my name?

Posted

luvdunhill:

For the Kapton, I would use the .001" thick stuff. Will definitely need TIM for both sides, since it does not conform to the surface like a sil pad does.

One idea I've had is to directly mount the device to a copper heat-spreader with goop, then place the insulator between the junction of the heat-spreader and heatsink. With a larger surface area, the impact of the lower performance would decrease. The issue with this would be the added capacitance from the heat-spreader, which I'll need to find out if it would be an issue.

I also plan on using a clamping bar to mount the device, using a torque driver to make sure the force applied is evenly distributed. From what I've read clamping force makes a decent bit of difference in performance.

I'm still researching, so these are all just ideas at this point :) What's your preferred thermal interface material and/or insulator material?

Speaking of CanJam, I might just be able to make it out there. Anyone need something (inexpensive) from Japan? :cool:

Posted
Good to know, will that still be running at 11:30? Where do I sign up? Also, can I make use of that considering I wont have a room reserved in my name?

The Hilton's proposal seemed to make the airport shuttle offer open ended without time restrictions. When you arrive we can talk to the Hilton on your behalf. ;) No worries.

Posted

Backup/new revision MX518 and Qck mini mousepad

Killer combo. The scroll wheel on my 1 year old MX518 was getting wonky and I didn't want to open it up without some sort of backup. The new revision, through a combination of new style of feet and fresh feet, slides really really well. The Qck mini is a good step above the fUnc Surface 1030 too.

Guest
This topic is now closed to further replies.
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.