(above question) and can i use a fender strat guitar with this amp instead of a bass? and are there things i should know before using this amp?
The power cable thing could potentially be a serious problem, since it seems the ground wire is lifted or missing. I'd definitely check this with a knowledgeable person if I were you. It may be as simple as changing to another AC power plug and connect the earth/ground wire. Do you need an extra preamp? No. Any combo amp have two amp stages built in: pre- and power amp. Adding and extra preamp is highly unlikely make the sound better. You will probably just add hiss and noise. This is not a great amp for playing guitar, although you won't ruin anything by doing it. Just plug yoiur guitar in and see if you like the sound or not.
You have three questions, let's see if I can get you three satisfying answers. Does it need a pre-amp? That's kind of like asking, does my dvd player need surround sound? In short, yes. But really, no. A good preamp will make your sound much better if used effectively. Can I use a Fender Strat guitar with the amp instead of a bass? Yes. Playing a guitar through a bass amp is done from time to time. There are pros and cons. The big pro is the low end and the volume. The big con is that you lose your high end pretty much entirely. So, you will sound pretty muddy and gross. But, you can do it and it shouldn't blow up at low/moderate volume levels. Are there things I should know before using this amp? Have fun, learn to play, when you know you will play for a long time - upgrade to tube.
