No one said anything about Kasumi's horizontally mounted heat sinks. I think that's worse. No offense Kasumi.
Those are the heat sinks I had on-hand. The other I have are too small.
The way things go today, this amp will evolve into something else or bigger.
I'm aware the L bracket is not in a good position, but, I'm not sure the position of the bracket is a problem and it's a large heat sink. It's effectively 1/3 of the way down on the HS. The way the heat sinks were sold to me, was with 2 aluminum plates to fill a routed hole on the face of the heat sink. The plates are stacked. I didn't trust mounting any transistor on them. This sort of made it a problem as to how I was going to mount the FETs and work on them at the same time.
The L bracket is 3mm, and using very good conductive paste. I was told once that dissipation was about surface area and not thickness of a heat sink. If anything, the bracket should be longer. My Mini-A survived for years playing in humid, +90 degree Fahrenheit summers. L bracket is in the same manner as this new amp. Mini-A runs at 2 amps per channel.
I hope this is the last case I have to build. Looking forward to the DIYAudio.com cases. It takes a lot of extra time to build cases and the cost difference is, well, let just say it's worth waiting and saving up.
I think it will survive. If the amp doesn't survive, so what. It's not the last amp I'll build and will learn my lesson.
People around here talk about being brave DIY'ers, but there's a difference between being brave, foolish or practical. I believe I fall in between foolish and practical.
Thanks for the comments.
BTW- I don't like T-03 cases. Would choose TO-247 over TO-03 cases any time. Hope the new SITs continue to use TO-247 cases. Know what I mean?
V~
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I understand where you are coming from with this situation.
I just don't think it's a big issue.
It's good that it's spelled out for new DIYers, so they don't make the mistakes I made. Mine is not an example of a technically good amp case. But it looks cool! 
Truthfully, anything can be picked apart, if you look closely enough.
Anything.
I just don't think it's a big issue.
It's good that it's spelled out for new DIYers, so they don't make the mistakes I made. Mine is not an example of a technically good amp case. But it looks cool!
Truthfully, anything can be picked apart, if you look closely enough.
Anything.
My case had to endure about 15 different amp tries, the same is true for my preamp case...
I have the greatest difficulties to publish any picture....all the holes, the dirt, the twenty times resoldered connections.......
If I would only be like other people, doing one amp perfect and three years afterwards another perfect amp ....
but me.....always is the cover of the case unscrewed and three times the week there is the opened and modified amp my lunch......!
I am afraid this will not change for the next time....
I have the greatest difficulties to publish any picture....all the holes, the dirt, the twenty times resoldered connections.......
If I would only be like other people, doing one amp perfect and three years afterwards another perfect amp ....
but me.....always is the cover of the case unscrewed and three times the week there is the opened and modified amp my lunch......!
I am afraid this will not change for the next time....
Generg, love your work and your persistance. Keep it up. I have always been interested in your Mu/J2 work.
Case appearance doen't matter. A friend in my audio group saw my system and didn't think much of it on appearance. Once he heard it, he said and I quote, "You can't let the others in the group hear this, you'll have a revolution on your hands." Best compliment I ever received!! Owe it all to you guys and I never take credit for any of it. You are the geniuses!
Case appearance doen't matter. A friend in my audio group saw my system and didn't think much of it on appearance. Once he heard it, he said and I quote, "You can't let the others in the group hear this, you'll have a revolution on your hands." Best compliment I ever received!!
Owe it all to you guys and I never take credit for any of it. You are the geniuses!
Hi vdi_nenna,
I think that the main thing that ZM wanted to warn you about is that heat tends to go upwards and if you mount your SITs so high up the heatsink the heat won't spread evenly, and the lower parts of the heatsink will be much cooler i.e. unused and your SITs will needlessly be exposed to much higher temperature. Lowering the position of L-profiles to about 2-3 inches above the bottom would put your SITs in much more comfortable temperature zone.
I think that the main thing that ZM wanted to warn you about is that heat tends to go upwards and if you mount your SITs so high up the heatsink the heat won't spread evenly, and the lower parts of the heatsink will be much cooler i.e. unused and your SITs will needlessly be exposed to much higher temperature. Lowering the position of L-profiles to about 2-3 inches above the bottom would put your SITs in much more comfortable temperature zone.
Generg, love your work and your persistance. Keep it up. I have always been interested in your Mu/J2 work.
Case appearance doen't matter. A friend in my audio group saw my system and didn't think much of it on appearance. Once he heard it, he said and I quote, "You can't let the others in the group hear this, you'll have a revolution on your hands." Best compliment I ever received!!
generg, What he said! Choos (sp?)
Thanks Juma. I know, but I can't move the L bracket on one of the heat sinks. See pic attached.
On the right heat sink back corner is a set of stacked plates that are not physically flush with the face of the heat sink. It's imperfect. The plates are more or less cometic.
If the L bracket is moved down, the same problem exists because of the plates, except it's half the heat sink in the lateral direction that's not being utilized.
This heat sink was meant for an F5, where there would be more space to mount TO-247 directly on he heat sinks, without the aid of the L bracket.
If I mount the L bracket vertically, that's not good either. Best thing to do is flip the heat sinks and have the bracket be lower, but does that make sense?
Heat distribution is still uneven. It's still not in the middle of the heat sink.
On the right heat sink back corner is a set of stacked plates that are not physically flush with the face of the heat sink. It's imperfect. The plates are more or less cometic.
If the L bracket is moved down, the same problem exists because of the plates, except it's half the heat sink in the lateral direction that's not being utilized.
This heat sink was meant for an F5, where there would be more space to mount TO-247 directly on he heat sinks, without the aid of the L bracket.
If I mount the L bracket vertically, that's not good either. Best thing to do is flip the heat sinks and have the bracket be lower, but does that make sense?
Heat distribution is still uneven. It's still not in the middle of the heat sink.
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Yes, this way or that way there's always something that needs extra care or attention. Never you mind, it won't kill the SITs for sure. It's just that nagging feeling that it could have been made a bit better...
cool work! and don't worry so much about the heatsink i have small ones and can lay my hand on it few minutes without "barbecue" effect with 40W on the 2SK82
just to say i found that the SIT needs a good preamp in front of it , i have a passive LDR and it never sound good with it. so i have built a little DC coupled B1 buffer and the combo sounds far better
just to say i found that the SIT needs a good preamp in front of it , i have a passive LDR and it never sound good with it. so i have built a little DC coupled B1 buffer and the combo sounds far better
Thanks juanitox.
This makes me wonder if my smaller heat sinks, already drilled for TO-03, would have worked. Will take picture and post it. I have 4 of them. They are maybe 5x5x3 inches in size, but have fins in all directions like Mike's photo in L'amp CCS article. Although on visual inspection, not as heavy an extrusion as Mike's heat sink.
Do you have a photo of your amp here?
Found a picture on the web. the one in the back. Not exact, but close. Mine is more like a cube.
Damn.
This makes me wonder if my smaller heat sinks, already drilled for TO-03, would have worked. Will take picture and post it. I have 4 of them. They are maybe 5x5x3 inches in size, but have fins in all directions like Mike's photo in L'amp CCS article. Although on visual inspection, not as heavy an extrusion as Mike's heat sink.
Do you have a photo of your amp here?
Found a picture on the web. the one in the back. Not exact, but close. Mine is more like a cube.
Damn.
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this is mine..
An externally hosted image should be here but it was not working when we last tested it.
That's it?!?!?! That's all? Tell me they go into the case, please!
Had no idea it could be that small!! The extra heat sink I have are at least that big, maybe bigger.
Also have 8 heat sinks that are bigger than that one, if I take apart my Zen v1. I used the transfo from the Zen 1. It ran at 2 amps.
did I mention I have 2 extra 2sk82s not in use?
Nice wood case.
Tell me they go into the case, please!Had no idea it could be that small!! The extra heat sink I have are at least that big, maybe bigger.
Also have 8 heat sinks that are bigger than that one, if I take apart my Zen v1. I used the transfo from the Zen 1. It ran at 2 amps.
did I mention I have 2 extra 2sk82s not in use?
Nice wood case.
