They had 600 watters too I believe, which would have meant only one per channel. They had a mogul base (the big one) though, and I thought with only one per box, people would think I was trying to make a lamp!
My son already asked me if I had them on there just to look weird- what a letdown. I agree with Nelson- they look
Anyway, I suppose they might become rare, but at the output we are using them for, they shouldn't ever burn out, its physical damage to look out for.
I hope you guys stay subscribed to this thread! I'll have questions soon!
My son already asked me if I had them on there just to look weird- what a letdown. I agree with Nelson- they look
Anyway, I suppose they might become rare, but at the output we are using them for, they shouldn't ever burn out, its physical damage to look out for.
I hope you guys stay subscribed to this thread! I'll have questions soon!
I was planning originally to make a wood cube with the stack coming out the top. Maybe I'll still do that eventually. In the mean time I'll put the 10 watt resistor under the stack probably, Or the fan idea would be great if the heatsinks are too small.
While the cap would fit, I think I would rather use it for something to do with airflow.
I am planning on making rectangular wood caps for the sides...
While the cap would fit, I think I would rather use it for something to do with airflow.
I am planning on making rectangular wood caps for the sides...
Piglet,
that is a smashing idea, think it would look great.
But only without the air horns from the double barrel 40DCNL Weber, it is essential that you leave these off and send them to me, Pronto !
Those bulbs look like Little Helper, you're Gyro Gearloose right ?
Can't be, you don't look like a chicken.
that is a smashing idea, think it would look great.
But only without the air horns from the double barrel 40DCNL Weber, it is essential that you leave these off and send them to me, Pronto !
Those bulbs look like Little Helper, you're Gyro Gearloose right ?
Can't be, you don't look like a chicken.
But wots the sport in that?
Ok Ok, that's the first bit of information that would actually be useful to someone following in my footsteps... I DID claim that this thread would help those that follow...
Nelson, how DO you think the Jfets would respond if you heated a 1/8 inch plate of copper from the back with a torch until some solder placed on top melted, then slapped the jfet (brushed with flux) on top and let it cool to room temp? Would it be cooked? or do you think it would survive?
It appears that surface mount and its relatives were designed
for something like that, but I'm very hesitant to apply such
techniques.
I coat the surface with white goop and press it to an anodized
surface, trusting the anodizing to create an adequate insulated
layer. Then I solder the leads to the edge of a pc board whose
thickness is just about that of the offset of the leads from the
flat metal surface of the package (about .062 in).
It has worked without fail so far.
for something like that, but I'm very hesitant to apply such
techniques.
I coat the surface with white goop and press it to an anodized
surface, trusting the anodizing to create an adequate insulated
layer. Then I solder the leads to the edge of a pc board whose
thickness is just about that of the offset of the leads from the
flat metal surface of the package (about .062 in).
It has worked without fail so far.
The blowtorch idea sounds iffy to me. The amount of heat energy required to get that much copper up to 350-400 degrees or so isn't going to dissipate rapidly, so the device will be cooking for quite some time, comparatively speaking. Most temperature ratings for devices specify a time (e.g. 10 seconds) that you can raise the temperature to such-and-such. I think you'll exceed the time, if not the temperature.
So far, I'm still pleased with the basic clamp idea. Someone (grataku?) posted a diagram similar to what I'm doing in the JFET group buy thread. I just popped a couple of holes in the end of some junker heatsinks, tapped them for 6-32 screws, and strapped the little boogers down with a short piece of 1/8" aluminum. Grease, but no insulator. One device per heatsink. Insulate the heatsink electrically, rather than the device. Realistically, 5 to 10W isn't that intimidating to dissipate. It's a whole lot easier than getting rid of 30 to 50W like we do when we run up class A output devices.
If the 'GreyLabs' comment in an earlier post was directed at me, I haven't kicked anyone out of the JFET purchase. At the moment I'm waiting to hear back from Shawn Fogarty. Yes, it's frustrating to wait, but it's also frustrating to have everything going in twenty directions at once without a coherent game plan. Try to look at it from his point of view: Nelson publishes the Zen variant, without warning a hundred e-mails and phone calls come in, a few people willing to brave the initial buy-in emerge, then those fall silent, only to be replaced by others, who in turn are replaced by others...they poor guy has every reason not to take DIY folks seriously. From his point of view, he's had to work up quotes (even if he's just running a finger down a quantity/price chart) a couple of dozen times now and not made a single sale. How would you feel if you were in his shoes? A little frustrated, perhaps? As I said before...patience.
Incidentally--and again, this is assuming that the GreyLabs comment referred to me--have I ever billed myself as GreyLabs? I can't remember doing so, but then I get so absent-minded sometimes that I forget where I parked my car. Makes me wish I had one of those nifty little doo-dads like Batman has, where you push the button and the car comes to you.
Anyway, I am, as I always have been...Just Me.
Grey
So far, I'm still pleased with the basic clamp idea. Someone (grataku?) posted a diagram similar to what I'm doing in the JFET group buy thread. I just popped a couple of holes in the end of some junker heatsinks, tapped them for 6-32 screws, and strapped the little boogers down with a short piece of 1/8" aluminum. Grease, but no insulator. One device per heatsink. Insulate the heatsink electrically, rather than the device. Realistically, 5 to 10W isn't that intimidating to dissipate. It's a whole lot easier than getting rid of 30 to 50W like we do when we run up class A output devices.
If the 'GreyLabs' comment in an earlier post was directed at me, I haven't kicked anyone out of the JFET purchase. At the moment I'm waiting to hear back from Shawn Fogarty. Yes, it's frustrating to wait, but it's also frustrating to have everything going in twenty directions at once without a coherent game plan. Try to look at it from his point of view: Nelson publishes the Zen variant, without warning a hundred e-mails and phone calls come in, a few people willing to brave the initial buy-in emerge, then those fall silent, only to be replaced by others, who in turn are replaced by others...they poor guy has every reason not to take DIY folks seriously. From his point of view, he's had to work up quotes (even if he's just running a finger down a quantity/price chart) a couple of dozen times now and not made a single sale. How would you feel if you were in his shoes? A little frustrated, perhaps? As I said before...patience.
Incidentally--and again, this is assuming that the GreyLabs comment referred to me--have I ever billed myself as GreyLabs? I can't remember doing so, but then I get so absent-minded sometimes that I forget where I parked my car. Makes me wish I had one of those nifty little doo-dads like Batman has, where you push the button and the car comes to you.
Anyway, I am, as I always have been...Just Me.
Grey
Variac said:
a combination of glueing and clamping a JFET on a strip of copper with a spring looks like a safer way to me.
Having seen some of the modern applications in the car, aeroplane and yachting industry i'm very impressed by contemporary chemical bonding techniques.
Bonding, not bondage !
Mr Rolllins,
your A-X development is starting to have a life on its own, it seems.
As you are embarking to become a US Lovoltech distributor, you'd be a second customer of proportion next to NP.
In a stroke of vision, i saw Pass Labs and Grey Labs side by side on this forum, you should be familiar with having visions.
The thought struck me as amusing, pardon my awkward sense of humor.
I wanted the batmobile too, couldn't afford it.
Gotta run, there's a wave of molten queso reported heading for the coast line.
Lots of good info coming out here.
My biggest concern about soldering the jfet was heat retention also but I didn't want to lead peoples responses.
If the plate is heated slowly until the solder just melts, I don't think there would be a problem with overheating, but I agree with Grey that it will take quite awhile for the copper to cool and in the interim the part might well cook. It is true that components are specced for a temp for a certain amount of time.. SO the idea of quickly cooling the copper comes to mind, but that might lead to warping which would require grinding the back of the plate.
The thought occured to me because the device looks like it was designed for surface mounting- but for our purposes there is probably no need. In the new state, when all citizens have access to JFETS, then I'll bet we see some experiments like this. Since I have just 2, no thanks!
Getting bulbs in Mexico- now that is sporting! and probably a lot of fun!
My biggest concern about soldering the jfet was heat retention also but I didn't want to lead peoples responses.
If the plate is heated slowly until the solder just melts, I don't think there would be a problem with overheating, but I agree with Grey that it will take quite awhile for the copper to cool and in the interim the part might well cook. It is true that components are specced for a temp for a certain amount of time.. SO the idea of quickly cooling the copper comes to mind, but that might lead to warping which would require grinding the back of the plate.
The thought occured to me because the device looks like it was designed for surface mounting- but for our purposes there is probably no need. In the new state, when all citizens have access to JFETS, then I'll bet we see some experiments like this. Since I have just 2, no thanks!
Getting bulbs in Mexico- now that is sporting! and probably a lot of fun!
Variac,
I have done quite a lot of soldering to SMD and TO220 to copper bases for quite long times, much more than 10 sec's.
This was on switching fet's and charger pass fet's. Never ever had any trouble. Would not know if this also applies to a super JFET Amp. But I will certainly try it. I have some 15 x 3 mm copper bar and will mount them with two holes adjacent to the chip. I have the idea that a great heat capacity (mass) will be good to keep the chip temp constant.
All this when I can get hold of the parts!!
Rick
I have done quite a lot of soldering to SMD and TO220 to copper bases for quite long times, much more than 10 sec's.
This was on switching fet's and charger pass fet's. Never ever had any trouble. Would not know if this also applies to a super JFET Amp. But I will certainly try it. I have some 15 x 3 mm copper bar and will mount them with two holes adjacent to the chip. I have the idea that a great heat capacity (mass) will be good to keep the chip temp constant.
All this when I can get hold of the parts!!
Rick
And here is a place that sells small squares of copper
http://www.enameling.com/page20.html#Squares
You have to make sure to get the flat, not domed ones. I guess we are off topic a bit, but I'd imagine that throwing the soldered copper plate/JFET on a wet towel would cool it pretty quick.
Advantages? Can use silpad or mica under the copper because the plate is big and will spread the heat. Can make higher output amp with a single device.
Anyway, we'll leave that for when we have lots to play with.
http://www.enameling.com/page20.html#Squares
You have to make sure to get the flat, not domed ones. I guess we are off topic a bit, but I'd imagine that throwing the soldered copper plate/JFET on a wet towel would cool it pretty quick.
Advantages? Can use silpad or mica under the copper because the plate is big and will spread the heat. Can make higher output amp with a single device.
Anyway, we'll leave that for when we have lots to play with.
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