I am living and working in the US now, so it will be some time before we can visit again. I have a panda friend wanting her snacks, so I hope it is soon 🙂
Thanks all of this communite helping,special huge thanks Nelson.I have finished CCS testing today.the current is very stable.The key parts is the 0.2R resistors.this will impact the CCS current.
In the amp board,I have integrate the 2SK170BL/2SJ74BL buffer and use a seperate power for it.
attached some pictures.next step is connect the together.
In the amp board,I have integrate the 2SK170BL/2SJ74BL buffer and use a seperate power for it.
attached some pictures.next step is connect the together.
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one quesiotn for the 28V voltage,it will be took more than 1.5 hours the test point voltage will be normal to 28V,right now the CCS and bottom transistor really hot and the heatsink about 55 degree,and it stay at 34V very long time and drop to low very slow. does this is normal behavior？
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You got a lot of mass there with those sinks. Based on cold ambient temps it could take that long, mine take about an hour to reach equilibrium. Re-adjust to 28V or 1/2 rail voltage after it's fully warmed up. Yes, this amp runs hot, 55C is still safe.
I'm back working on my full power Schade. Two things that have helped so far. I eliminated any 'improvements' and created an exact duplicate of the original circuit. Also, the ZM inspired greeny bias circuit works wonders. I still may be on the hairy edge heatsink wise but only time will tell! 
Regards,
Dan
Regards,
Dan
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A big chunk of aluminum is always good for this baby!
Vertical fins - yep....🙄
You get nice music and very good extra heating system.😀
Greets
Dirk
Vertical fins - yep....🙄
You get nice music and very good extra heating system.😀
Greets
Dirk
For reasons unknown to me the picture did not post in the correct orientation. Or, you and ZM are having a little fun with me! 😉
to Dan #1491
Hello Dan,
I would never make a joke about.... 🙄
But I feel a little 90 degree left stretch in my neck...😀
To be serious. I hope your amp will run soon and will give you a real joy
in listening!
Dirk
Hello Dan,
I would never make a joke about.... 🙄
But I feel a little 90 degree left stretch in my neck...😀
To be serious. I hope your amp will run soon and will give you a real joy
in listening!
Dirk
I haven't burned up any MOSFETs in four days. A personal best for me! 
Maybe the heatsinks are big enough!
Regards,
Dan 😉
Maybe the heatsinks are big enough!
Regards,
Dan 😉
