Tim: >> didn't expect - if you ground one side or the other of a floating Les: > Most likely you have 60Hz pickup. Since the transformer is not > grounded, it is a great 60 hz inductor, but the ungrounded balanced > condition makes it common mode so no response on the VU meter. > Grounding one side adds 60hz becuase it is no longer common mode. Try > the Oscilloscope on it. I'd already done that, no mains on it at all. This desk buried the output transformers into the middle of the chassis, to get them as far away as possible from outside interference, and has an external power supply. I can see some experimenting coming in with any spare audio transformers I've got kicking around. Many years ago, back when I was young and dinosaurs roamed the earth, I just couldn't resist putting a 240 V to 6 V power transformer backwards on the output of my oscillator (stepping up the output), just to see what it could do. Partially inspired by the story at college how someone had a done a frequency response test on a captured spider, back when they had valve oscillators that could output about 100 Volts... Instant torture device. Strange how some frequencies really hurt, and others are hardly noticeable. -- (This computer runs FC7, my others run FC4, FC5 & FC6, in case that's important to the thread.) Don't send private replies to my address, the mailbox is ignored. I read messages from the public lists.
