Based on 2SK184 datasheet, the middle pin is GATE, not Source. Kindly check.

Thanks for pointing out!

 

Someone in another forum wrote that this design that I have posted, it is not suitable to running from DC adaptor only battery, due to the noise. What do you think about that? Is it a legit issue?

 

Yes. Humming noise would be a problem.

 

Yes. Humming noise would be a problem.

I have another version of the circuit, what about that? Can that have less noise? (the right one on the photo)

 

Someone in another forum wrote that this design that I have posted, it is not suitable to running from DC adaptor only battery, due to the noise. What do you think about that? Is it a legit issue?

If your latest or previous version is powered by DC adaptor which have ripples, it would produces the humming noise. Running on 9V battery or a clean DC source should be fine.

 

I have just received a comment from a former technician of Marshall that hum may not be a problem. The good thing is I get as many advices as the number of people I am talking with