DIY Sony VFET pt 2 (N-Channel Build)

When a 120 Hz hum is present after attaching the interconnects, that usually means there is an issue with the grounding scheme of the preamp or signal source.

The kit SMPS ground is electrically connected to its AC inlet ground prong. If there is a different arrangement for the preamp, or they are on different AC strips, then there can be ground loop problems.
 
BOM says .4W≠.25W

Look at it! So tiny.
 

Attachments

  • PXL_20210902_123254872.jpg
    PXL_20210902_123254872.jpg
    1,015.2 KB · Views: 263
Last edited:
Just wait till you open the Detailed Parts List for the VFET front end card named Marauder. It provides error prone builders MANY more opportunities to order the wrong part, accidentally skip a line-item, mistype one character in a stock number, confuse nanofarads with microfarads, etc. A wonderful training exercise to (painfully) discover What Can Go Wrong.
 
I'm not sure if there is a real grounding issue or not. I had been trying to test with just a tablet as source, no preamp. After connecting a real preamp, the hum is completely gone.

I'm going to tie down the wiring, close it up and try in my primary system.

Thanks for the help, Zen Mod, astouffer and TungstenAudio.