I have FRED diodes in mine two monos Class A power amps and I want to know if it's a good idea to replace with SiC diodes same V & A or I have to check others specs?
I had to search the Internet to understand what is a FRED diode: A Fast Recovery Epitaxial Diode. A silicon diode with fast switching characteristics - intended for switching purposes. Not a Schottky diode.
The relevance in a class A amplifier is not obvious. Could you please tell us for what purpose the FRED diodes are used?
The relevance in a class A amplifier is not obvious. Could you please tell us for what purpose the FRED diodes are used?
I don't know where installed in mine power amps, I guess convert AC to DC for the reservoir bank capacitors PSU.
If you just need to replace something it depends on how it’s used. For a 50-60 Hz supply with a big transformer the schottky will work. If it is a switch mode supply, you would need to stay with a FRED, of at least equivalent speed.
If building from scratch, I would first assess the need for a fast diode. Faster is not always better, especially at power line frequency. Regular diode with a snubber still beats a FRED for high frequency noise generation. Costs less, and takes the turn-on surge better.
If building from scratch, I would first assess the need for a fast diode. Faster is not always better, especially at power line frequency. Regular diode with a snubber still beats a FRED for high frequency noise generation. Costs less, and takes the turn-on surge better.
I havent found a need for fancy diodes in power amps (up to 60V DC)
For valve amps with b+ of 100+ volts then Schottky is required to stop switching spikes.
For valve amps with b+ of 100+ volts then Schottky is required to stop switching spikes.
If you do not know exactly what purpose the diodes serve and all seems to work well, it a gamble with little chance of winning if you change the diodes.
Who made the class A amplifier?
Who made the class A amplifier?
Erno Borbely is (was?) a very experienced amplifier designer of substantially Norwegian origin. Norwegians generally know what they do except when trying to make goat-chese (they put caramel in and it becomes sweet 😱).
If your amplifier is made according to his instructions, don't modify it. If you insist going on, we need to know which exact design.
If your amplifier is made according to his instructions, don't modify it. If you insist going on, we need to know which exact design.
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