Hello colleagues! A clone of Aleph3 was brought to me. It was assembled by a master unknown to me. In a large aluminum case with large heatsinks. Chinese boards inside. The amplifier works and works very well! That is VERY good! However, it gets very hot. The temperature of the radiators is about 60 degrees Celsius! I have read that the circuit of this amplifier is designed in such a way that, with serviceable parts, it does not require adjustment. I admit that this is his normal mode of operation, but still it seems to me that he is excessively hot. Therefore, I have a question. Can I check the operating modes of the transistors and make sure that everything is in order or is there still a problem. It's still a Chinese assembly! Thank you!
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I'm sure a moderator will hop in soon, but this is an English language forum.
This is what Google Translate provided...
Hello colleagues! They brought me a clone of Alef3. It was assembled by a master unknown to me. In a large aluminum case with large heatsinks. Chinese boards inside. The amplifier works and works very well! Very well! However, it gets very hot. The temperature of the radiators is about 60 degrees Celsius! I read that the circuit of this amplifier is designed in such a way that, with serviceable parts, it does not require tuning. I admit that this is his normal mode of operation, but still it seems to me that he is excessively hot. Therefore, I have a question. Is it possible to check the operating modes of the transistors and make sure that everything is in order or is there still a problem. It's still a Chinese assembly! Thank you!
This is what Google Translate provided...
Hello colleagues! They brought me a clone of Alef3. It was assembled by a master unknown to me. In a large aluminum case with large heatsinks. Chinese boards inside. The amplifier works and works very well! Very well! However, it gets very hot. The temperature of the radiators is about 60 degrees Celsius! I read that the circuit of this amplifier is designed in such a way that, with serviceable parts, it does not require tuning. I admit that this is his normal mode of operation, but still it seems to me that he is excessively hot. Therefore, I have a question. Is it possible to check the operating modes of the transistors and make sure that everything is in order or is there still a problem. It's still a Chinese assembly! Thank you!
Even though the Aleph3 has no adjustments, you can still check that the supply voltages and bias currents are as they should be. If yes, the heat sinks are too small. If no, tell us what you measure and then I am sure someone can suggest ways to troubleshoot it.
***Thanks for the answer! I'm ready to see the currents, but tell me WHAT they should be! I'll measure the supply voltage shortly.
The Nelson Pass method of heatsink temperature is to put your hand on the heatsink and see how long you can stand the heat:
Blimey hot is 10 seconds hands on = 45 deg C.
Crikey hot is 5 seconds = 50 deg C.
Bloody hot is 2 seconds = 55 deg C.
X*?@! is 60 deg C.
I guess X*?@! is still okay for some, but maybe you shouldn't go much higher.
Excessive dissipation means either too much voltage or too much current (or both). So I'd suggest to check the rail voltage and the idle current. You can get the current by measuring the voltage drop across the source resistor(s) of the output device(s), and divide this by the resistance of the source resistor(s).
Blimey hot is 10 seconds hands on = 45 deg C.
Crikey hot is 5 seconds = 50 deg C.
Bloody hot is 2 seconds = 55 deg C.
X*?@! is 60 deg C.
I guess X*?@! is still okay for some, but maybe you shouldn't go much higher.
Excessive dissipation means either too much voltage or too much current (or both). So I'd suggest to check the rail voltage and the idle current. You can get the current by measuring the voltage drop across the source resistor(s) of the output device(s), and divide this by the resistance of the source resistor(s).
***Thanks! Checked by hand! 🙂 I can hold my hand for a minute or more. But it does feel hot.
I'll check the voltage soon!
If you can touch the heatsinks with your hand for a minute or more, then the amp is normal for a Class A design. The large heatsinks are working well to dissipate the heat.
Then it's not hot enough 🙂
Okey, that's a good start to figure out how to make it run even hotter 😎
According to the service manual, the bias current is around 2A for the completed amplifier.
