View single post by Jan
 Posted: Aug 17th, 2014 02:07 PM
PM Quote Reply Full Topic


Joined: Jun 5th, 2012
Location: Inverness, Scotland
Posts: 85
Hi Itsu,

From the video I expect the hum is from unscreened wires feeding hi-Z inputs, both the BF256 FET and the audio amp - but I guess you know that.

Incidentally, I've had problems with FETs which were caused by different pin configurations to those that were published. Sometimes it depends on the manufacturer!

I'm curious to know what's causing the occasional high-pitched interference. Do you have any switched-mode power supplies nearby on standby? Or any data-though-the-mains equipment?

When I've had similar hum problems as a last resort I've switched off the workshop mains!

I like the magnets retained by tape as they try to repel each other - very simple but clever.

Thanks for posting the video.