after a few years of computer recording i decided to experiment with some tape recording. i bought a tascam 414 and 424mkII off of ebay recently. i've gotten some decent recordings of acoustic guitar with them, and also drums. however, i cannot get a decent electric guitar recording with them. the signal always distorts on the playback. i've messed around a ton with adjusting the trim levels, eq levels, using compression, and basic track leves with no avail. i'm using a sm57, although i've tested other mics to make sure it isn't a problem with the sm57. any idea what i could try?
This is a tough one to answer without being there in person to see exactly what is going on and to hear what's happening as well. It could be any number of issues.
If you are cranking up the amp fairly loud and have the SM57 right up on the grill, you could be overloading the microphone pre-amp on the Tascam 4-track machine. Most of those cassette four track machines don't have any input pads on the pre-amps, and the SM57 microphone doesn't have an output pad either... so, if the signal level is to hot for the microphone pre-amp, even at its lowest trim setting, then it's going to distort. If this is the case, simply try turning the volume of the guitar amp down to a much softer level and see if the distortion is still there. If you are getting distortion even at very soft levels, then it's something else in the signal chain causing the distortion. Also, you could try just grabbing the SM57 that you set up in front of the amp and talking or singing into it at a regular volume to see if it's distorting with your voice... if it is, then it's probably not an overload of the pre-amp problem.
If it's not the above problem, then you just have to go through a process of elimination to track down where the distortion is coming from. Try different inputs on the Tascam, try different microphone cables, try a different microphone, etc. Eventually you'll track down the problem.
If it is a problem with simply overdriving the input to your microphone pre-amp, but you need your amp cranked to get a certain sound out of it, then you should invest in some inline microphone pads to put between the microphone and the pre-amp. These are the types of inline pads I'm talking about:
Good luck with it!