buzz in audio

Typically, when you get a hum or buzz on a telephone, it's because there is a lower than normal impedance to ground in the system. Telephones are meant to have a balanced line, meaning that there is no "ground" connection to either of the two wires. Since your new device introduces the buzz into the system, we can reasonably assume that it has a leakage to ground. This is likely to be through the connection into the recording device, whether it be a cassette recorder, a computer, or whatever.

You have several options. (1) Return the device to the seller as being defective. It shouldn't cause the buzz. (2) Open the device and try to figure out the connections, and where the imbalance is being introduced. (3) Throw the device into the trash and chalk it up to bad experience.

If you choose door #2, you can get an idea of its contents by looking at

or Relate the innards of your device to the schematics and see which one is closer. Come back with more questions when you have more info.

--
Dave M
MasonDG44 at comcast dot net  (Just substitute the appropriate characters in the 
address)

Life is like a roll of toilet paper; the closer it gets to the end, the faster 
it goes.

Is the recorder connected to the AC line? If so, that is likely the cause of the problem. Try using a battery-operated machine.

RadioShack sells a similar device. I've used it several times, and had absolutely no problem.

thanks I tried that, no joy. I should mention this is a cisco ip phone, not an ordinary phone and it is powered from the mains through a 48v adaptor, so there's no disconnecting it from mains. Even if I disconnect the ethernet cable and switch off everything else the buzz is still there. At this moment I don't have a battery powered recorder, only mains powered units. I think my only solution here is to find some way or device that was specifically made to filter out this buzz, which I think is a standard 50Khz mains buzz. I'm sure I saw something like this once but can't remember where...