Originally Posted by Angel Switch
I just recently purchased a used Squier Jazz Bass Standard. It sounds fine, but whenever I turn up the bridge pickup, it introduces a really nasty hiss. This hiss changes its sound a little bit as I adjust the volume of the neck pickup, which leads me to think it's a problem in the bass/pickups/electronics. I, however, don't know a lot about these sorts of things, so I don't know where to start investigating/troubleshooting. Any ideas?
I don't know a lot about what you are talking about either! When you discuss these things you MUST be very accurate in your descriptions.
For example: As I understand it a Squier Standard Jazz bass is a passive bass. Put quite simply, passive basses do not "hiss". Hiss and that is a sound like escaping steam, is an electronic fault. That means it's in active basses or in your amp/preamp.
I suspect you are just calling higher frequency noise (often harmonics of power line "hum" or from high frequency power supplies) hiss. In that case it begins to make sense. I suspect your bass uses single coil pickups. When they are soloed they pick up hum which can also be other kinds of noise even of high frequencies. When both pickups are on full they supposedly cancel noise.
But there is more than one kind of noise. The other kind will give itself away if it changes when you touch ground such as the jack or strings. If that happens then the bass needs shielding like copper foil lining the electronics cavities.
However, IF the bass is active (takes a battery) and it is making a true "hiss" then the problem is the preamp in the bass which is noisy and can only be fixed by replacing it or the transistors in it.