PCB in the waiting period, to give KSA50 design a preamplifier.
But the best vacuum tube amplifier, must have good power. This reminds me of the ARC, as shown below.
I want to do with this power, should be able to design a more quiet pre-amplifiers.
But the best vacuum tube amplifier, must have good power. This reminds me of the ARC, as shown below.
I want to do with this power, should be able to design a more quiet pre-amplifiers.
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Actually, the GBU bridge rectifiers with a heatsink mounting hole are not inferior, provided they are mounted to a heatsink.
Attached to a heatsink, the mentioned D35XB60 can indeed handle 35A at 100C.
It's just that current handling capability of these packages drops dramatically in an open air mounted position, down from 35A to less than 6A at 100C.
Actually, the GBU bridge rectifiers with a heatsink mounting hole are not inferior, provided they are mounted to a heatsink.
Attached to a heatsink, the mentioned D35XB60 can indeed handle 35A at 100C.
It's just that current handling capability of these packages drops dramatically in an open air mounted position, down from 35A to less than 6A at 100C.
Today I purchased just bought some Japanese-made 25XB60 Rectifier Bridge, PCB came back test on the know.
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ok, your statements are true. So what? The conditions you are exposing are not the ones in this amp.The funny part :
A plastic GBU bridge rectifier package has a thermal resistance from junction to case of roughly 9 C/W.
Suppose the diodes inside have a Vf of 1 volt, at full peak current load that translates to 70 W (35A * 2 diodes * 1V)
In free air a GBU package would reach 630C above ambient.
Is this amp consuming 70A?
Regards,
Regi
It IS a Class-A amp, and some people like to run 'em hot till they burn... Which means as much current as the output devices can safely handle.
😱 ( mr. 😎 )But no, not 70 amps.
If you bothered to do the math i've posted you'd discover that the diode temperature of a single bridge rectifier would be some 90C at 1.8A idle current, for 25C ambient.
If the charging current is divided between 2 bridge rectifiers it's some 58C.
Temperature inside the case of a class A power amp isn't 25C however, the best to expect is some 40C.
That elevates the idle diode temperature to 74C minimum.
Drive the KSA50 harder and diode temperature will go up a long way.
Easy remedy is adding a heatsink, which is what that type of bridge rectifier is designed for, adds longevity and allows to drive the output stage of a KSA50 to the level it was intended for.
YMMV.
hi gxcnabin
if you can give another stereo set of krell ksa 50 pcb
please dont forget me
btw why dont you give a place for big bridge rectrifier
for ixys or motorolla 3504 / 3510, i think everybody will happy
best regards, jeffry
if you can give another stereo set of krell ksa 50 pcb
please dont forget me
btw why dont you give a place for big bridge rectrifier
for ixys or motorolla 3504 / 3510, i think everybody will happy
best regards, jeffry
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