donw@zehntel (Don White) (09/17/88)
[cute phrase]
I recently saw a posting from Mike Gladden asking about noise on his
system. I had a simialar problem. My amiga was hooked up to my stereo
AND my VCR switch box. I had an awful hum.
I tried disconnecting things from the system one by one.(But leaving
the stereo and amiga hooked together). I found that my problem was a
loop involving my local TV Cable company. I called them, but they could
not isolate it.
So, I took matters into my own hands and transformer coupled their
signal and ISOLATED their ground. I used two 75 Ohm to 300 Ohm trans-
formers. I depended on the stereos' ground to maintain the signal
ground past the transformers. Then I got a video amplifier from Radio
Shack to step up the signal (their were losses due to the transformers).
It used to be painful to turn my stereo volume up only half way
because of the hum. Now I can turn it up all the way. The system is as
quiet as the proverbial mouse when the Amiga is not sending a signal!
And it roars like a lion WHEN IT IS SUPPOSED TO! (Yeah!)
I hope this is helpful to any and all who are having audio noise or
hum with their Amiga and other equipment.
Don White
{ihnp4 | akgua | seismo | tektronix}!zehntel!donw
Box 271177 Concord, CA. 94527-1177
karl@sugar.uu.net (Karl Lehenbauer) (09/21/88)
I had an incredible noise-in-my-amiga-connected-audio-system bug. I disconnected stuff piece by piece, and there were a lot of pieces cuz the ami runs into an audio board, serial and parallel ports to outboard gear &c &c, and the noise source turned out to be cable TV. I lifted the grounds on everything, gross, but it went away. -- -- uunet!sugar!karl, Unix BBS (713) 438-5018