unwanted distortion in signal

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Plugging a guitar or bass into my laptop's mic jack (using a 1/4 to 1/8 in adapter), I'm getting awful digital distortion whenever I play anything but very softly. The same problem happens when I run the signal through my Fender amp and out the Pre-Out jack.

Also, all of these inputs (as well as my mic) have a lot of background noise coming in.

Any suggestions to help would be much appreciated.

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Your laptop probably has an amplifier on the mic input that's expecting a really low signal. That's how mine is, and it adds tons of noise, too. There should be an option somewhere in the sound control panel to shut the boost off.

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The mic input is entirely the wrong one to use with any instrument. It's intended for a microphone... and nothing else. The gain is too high and the impedance too low - I'm not surprised you're having a problem.

The answer is to use the line input, but that might be too insensitive and you won't be able to get the level high enough (technically, it's also the wrong input to use as well, but you only have a choice of two and the line is the preferable one.) If this happens, then consider using a guitar FX unit to give you the extra signal level needed. This will match the guitar pickups more closely anyway and provide a good impedance match to the line input as well (you don't necessarily have to have any FX running, you can use it just as a pre-amp for the guitar signal).

Of course, some laptops don't even have a line in - in which case you are really stuffed!
Graeme

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I've never tried this but it might work: mic inputs are usually a few hundred Ohms impedance, while guitar inputs are usually greater than 10000 OHM impedance. Radio Shack sells a 1/4"-XLR impedance matcher that is used to attach guitars(high impedance) to soundboard mic inputs (low impedance) - that solves the same problem you have. But now you will need to go physically from XLR->1/8" for the PC-mic input.

WARNING: some 1/4" (phono)->XLR devices are just adapters (wiring straight through). Those won't help. You need the kind that matches impedance.

When going from the XLR (low impedance)->1/8" (low impedance PC-mic input), you will only need a wired adapter.

If you try this let everyone know if it helps,
Ken J Kelly

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Your soudcard has a mixer panel where you can set the gain. You need to lower it or use the line input in which case tou may have to raise or lower the gain to match the input signal.

I access the souncard controls in my win98 laptop by double clicking the speaker icon in the task bar and then selecting options, properties, recording.

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oh my god. you're using an amp head's pre-out to your laptop. you should be glad you didnt burn it out.... wow.

NEVER EVER EVER plug any amp heads into any input!

this is probably why you're getting distortion now, because its blown out.

RoNC

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rpc9943 wrote:oh my god. you're using an amp head's pre-out to your laptop. you should be glad you didnt burn it out.... wow.
Where did he even imply that? What he said was he had his guitar or bass plugged into the mic input - nothing about amplifiers anywhere.
rpc9943 wrote:this is probably why you're getting distortion now, because its blown out.
No - he's getting distortion because the mic input is way too sensitive for a guitars output - see my first post in this thread.

kenjkelly's impedance matcher goes part of the way to solving the problem, but most soundcards have lousy mic pre-amps in them and I suspect there will still be a lot of noise to contend with.
Graeme

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sorry
RONalds C

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