I have a high quality stereo system with a powered subwoofer. Could this be used as a decent 'practice amp'? I know I would need some kind of box to get a good signal into the receiver.
You need a combination pre-amp and EQ, like a SansAmp. But be prepared for far lower levels out of any stereo than you think you'll get.
With the right connectivity, yes. Yeah, some sort of eq would be best. I have done this quite successfully with a stomp box eq and a mono 1/4' --> dual mono rca cable. However to hear tunes at the same time you need a box that will combine 2 stereo rca sources into one (to combine your cd & bass or cassette & bass or whatever & bass). It is very easy to make. Joe.
+1 One of those cheaper Behringer BDI-21 preamps would probably work ok too. Keep Bill's advice in mind, and don't try to push that stereo and speakers like it's a bass amp, because it's not. I did almost the same thing about a year and a half ago when I was first getting back into playing. I had a really old receiver, and wired directly into the AUX inputs with my bass. It wasn't great, but it was "something", and I really needed something. You'll most-likely need a few adapters or homemade patch cords to go from 1/4" mono to dual RCAs for connection. Good luck, and don't blow the speakers! Mag...
This would really help. Plug it into your aux input (or which ever one you choose) and plug everything else into it. Problem Solved (for just over $30)!! Joe.
I have Line 6 Pod. One of the amp sounds is a Fender Bassman. Perhaps that will work. It will be afew days before I get my bass to try it out.