Thanks guys.
I have found the spreadsheet. I will do some homework first. At this point it seems prudent that I might have to add some more devices in parallel to carry the load since I have found a nice transformer that has 33-0-33 secondaries at 800VA.
As for heatsinks, I am thinking (note thinking..no commitment made yet) to use 2 Conrad MF35-151.5 heatsinks per monoblock. But first I have to make my SOA calculations, and then I will check to see if the heatsinks can handle that.
Regards
Henry van Eyk
PS. Andrew, I can not send PM at the moment, my account is still under moderation. If you want, you me send to me at henryve (at) gmail (dot) com.
I have found the spreadsheet. I will do some homework first. At this point it seems prudent that I might have to add some more devices in parallel to carry the load since I have found a nice transformer that has 33-0-33 secondaries at 800VA.
As for heatsinks, I am thinking (note thinking..no commitment made yet) to use 2 Conrad MF35-151.5 heatsinks per monoblock. But first I have to make my SOA calculations, and then I will check to see if the heatsinks can handle that.
Regards
Henry van Eyk
PS. Andrew, I can not send PM at the moment, my account is still under moderation. If you want, you me send to me at henryve (at) gmail (dot) com.
Heh, this is now third time I'm reading this thread over the past 18 months or so. And I still get more and more excited every time I'm reading this. I'm SO gonna have to build this amp!! 
I must check from local PCB manufacturer how much they would charge for few boards... btw is there any performance difference between Jans and Pink Mouses boards?
What a great thread this is!
I must check from local PCB manufacturer how much they would charge for few boards... btw is there any performance difference between Jans and Pink Mouses boards?
What a great thread this is!
Bob has some of the Pink Mouse boards available.
Have fun building and I'm sure you will like the amp!
Have fun building and I'm sure you will like the amp!
I most definitely will LOVE the amp, although it's been over 20 years since I heard it last time. It was paired with Apogee Duettas and with Calipers. Now they are getting a pleasure of driving my own speakers that are a lot like B&W 808's, well clone actually, except that I have used bit better parts all over 🙂
As a matter of fact I have thought about it, but I'm still waiting for the second set of x-over components. As soon as I got it all finished up, I'll post set of pictured and little story of building them. This shouldn't take more than 2 weeks max...
Housing and Layout...
When I had made up my mind, that I'm gonna build this Krell thingy. I was thinking of 6 channels, but now it's reduced into 4 channels only 🙂 because I figured that it'll be insane to drive single tweeter with this kinda amplifier. One for the bass and one for mid/high per speaker of course.
At first I had assembled all channels into single chassis, but when I checked weight I figured that it would be impossible to move the thing. So I remodeled chassis into stereo version, but as I want to use this heat sink (Alutronic PR-223) particularly, I didn't find good enough solution either. Either too much waste of space of too little space. So at this point it's single channel assembly, not that stereo is out of the question yet though.
I have some very usable 20mm and 30mm aluminum plates at my work and they're free for me to use. So I just have to buy some 5mm sheet for sides and top. My boss (his company) will sponsor my trafos, heatsinks, and capacitors.
Here's some pictures, any opinions?
When I had made up my mind, that I'm gonna build this Krell thingy. I was thinking of 6 channels, but now it's reduced into 4 channels only 🙂 because I figured that it'll be insane to drive single tweeter with this kinda amplifier. One for the bass and one for mid/high per speaker of course.
At first I had assembled all channels into single chassis, but when I checked weight I figured that it would be impossible to move the thing. So I remodeled chassis into stereo version, but as I want to use this heat sink (Alutronic PR-223) particularly, I didn't find good enough solution either. Either too much waste of space of too little space. So at this point it's single channel assembly, not that stereo is out of the question yet though.
I have some very usable 20mm and 30mm aluminum plates at my work and they're free for me to use. So I just have to buy some 5mm sheet for sides and top. My boss (his company) will sponsor my trafos, heatsinks, and capacitors.
Here's some pictures, any opinions?
Although the design is interesting I am not sure about the practicality of the input and speaker connectors on the side of the enclosure. You can never conceal the cable mess, especially if you are planning to have multiple units like that. Also, where will the power cable enter the enclosure? How about the power switch, fuse holder and the LED to indicate the unit is on?
Hi,
that sink looks like it might just cool one channel of a KSA50 Klone.
But it will run very hot.
that sink looks like it might just cool one channel of a KSA50 Klone.
But it will run very hot.
Very hot indeed, a 250mm section of PR223 is only good for 0.35C/W.
At the standard +/-37Vdc and 1.8A numbers of the Krill-50, the fashionable design will be a nice egg poacher.
At the standard +/-37Vdc and 1.8A numbers of the Krill-50, the fashionable design will be a nice egg poacher.
Hjmm... the design is not completed yet, there aren't even any screws to hold it together 😀
The power cable would go in, as of now, from the left side front corner near the odd box, that's actually inrush current limiter.
I'm not sure if I want any LEDs, but you're right about that it should have some indicator to see it's on/off state. Maybe I could hide couple LEDs behind the "handles", so that they would glow gently...
For the power switch I was thinking of those nice looking vandal proof switches with led, but not sure. That would add more stuff to layout due the fact they're rated only 5-24V. IF I decide to use low voltage switch it'll be at the center of front plate. But then again in case of "normal" switch, I'm pretty sure I'll put power switch and fuse holder near the AC power input.
Cords are simply something that you cannot hide in any case, unless you go totally wireless 😉
Besides, I kinda like to see cables, but not the AC power cable tho... I might even consider to draw it under the bottom plate 😕
I'd really like to run some heat dissipation simulations, but my SolidWorks/COSMOS license doesn't allow anything but the free stuff. The heatsink could be equipped with fan, wouldn't want to though, if it isn't absolutely necessary! Oh by the way, this mono concept weights 22.45kg (roughly 50lbs)
here's smallest stereo version, I could manage to do... power and output would all be in back plate.
The power cable would go in, as of now, from the left side front corner near the odd box, that's actually inrush current limiter.
I'm not sure if I want any LEDs, but you're right about that it should have some indicator to see it's on/off state. Maybe I could hide couple LEDs behind the "handles", so that they would glow gently...
For the power switch I was thinking of those nice looking vandal proof switches with led, but not sure. That would add more stuff to layout due the fact they're rated only 5-24V. IF I decide to use low voltage switch it'll be at the center of front plate. But then again in case of "normal" switch, I'm pretty sure I'll put power switch and fuse holder near the AC power input.
Cords are simply something that you cannot hide in any case, unless you go totally wireless 😉
Besides, I kinda like to see cables, but not the AC power cable tho... I might even consider to draw it under the bottom plate 😕
I'd really like to run some heat dissipation simulations, but my SolidWorks/COSMOS license doesn't allow anything but the free stuff. The heatsink could be equipped with fan, wouldn't want to though, if it isn't absolutely necessary! Oh by the way, this mono concept weights 22.45kg (roughly 50lbs)
here's smallest stereo version, I could manage to do... power and output would all be in back plate.
Attachments
Harry3; Looks like there's not that much more sinking after all. To my eye it's somewhere around 2x150mm while in my case it's 250mm.
Oh well, back to the drawing board then.. 🙂
Oh well, back to the drawing board then.. 🙂
2 off 150mm has twice the dissipation capability of a single 150mm.HellMan said:
A 250mm has only 29% more dissipation capability.
And your top row of devices will run much hotter than the lower row due to the symmetrical layout you chose.
