15lyl

Thank you for your explanation, Spritzer.

Such high voltage is too close to the head, will it affect the brain? say cancer.

Thank you Dr.Kevin.

Hope Kevin will explain the circuit detail.

So complicated !

https://drive.google.com/drive/folders/1r3g2TAtBUaBdiMorTWX7yYgeJ7maQbYW https://drive.google.com/drive/folders/0B7egryukiT7_TFlEQlBRejdVdDQ?resourcekey=0-nGWwBYQ_Uivj-ciBLYMeaA

https://www.richardsonrfpd.com/Products/Product/C2M1000170D

They are in China. 86 is China, Hong Kong is 852.

We cannot get these 2SK109 and 2SK389 anymore, they are obsolete for a long time, all of them are fake from AliExpress.

Hi Kevin, Thank you for your message about the bias of the cfa3 amp, I am running the ZF, by disconnecting the 4 600p, I could adjust the bias smoothly to 200mA, no squeak or oscillation any more. What are those 600P for?

I etched the board myself, am running the ZF. I can only stop the oscillation by connecting a 500P to the B, C of the output transistors, smaller than 500P can’t stop the oscillation. I may try to run the SS later to see the negative feedback will help the oscillation.

Thanks, I did so.

Hi Kevin, the 4 transistors around THAT340 are in different orientation, the THAT340 pnp C is to the following Tr E, while the npn is to C. which one is correct? All ON brand MJE15030, 15031 that I used in the power output had oscillation, some Motorola were stable. Is the fT30 too high?

I use this schematic for KGSS +-15V 15V.pdf