I got my Tascam connected to my new computer. I downloaded Audacity and tried it out. I get a regular interference blip which I recorded for a diagnosis!
It's on both mic and guitar in. On this recording I have boosted the sound with volumes on max and some compression so its easier to hear. I don't think the hiss is a problem at normal levels, but the bleeping is. It never happened on my old computer. I've switched off lights etc and nothing got rid of it. I'm guessing its the 50Hz thingy (don't know anything about it, and even less about how to get rid of it!)
I'm going to download Reaper now to see if it's there as well. In the meantime, any suggestions would be much appreciated. Thanks in advance.
One good thing about music is that when it hits you, you feel no pain - Bob Marley