I have a Roland/Boss GT3, which I use to get various distortion sounds. I like the sound for the most part, but I find that distorted sounds seem very ... "muddy" I guess would be the best way to describe it. Major chords, 7ths, etc, sound fine, or at least much better. Is there some common setting that can help clean up the sound at bit? What would be the most likely causes of this behaviour?
Quite possibly one of the best ways to remove muddiness from your overdriven tone (regardless of what chords you play) is through the use of a compressor. If you don't know what one of those is, check out this question. If you think you know what one is, you probably don't, and you should check out this question =D. I kid. In all seriousness though--JFET based and digital overdrive pedals will do this. If using a compressor in front of (or behind, some players like that too) the overdrive--and using it correctly--doesn't work, then consider reducing the amount of distortion on your overdrive or changing some parameters on how you equalize the tone pre and post drive.
Before I describe that a little more in depth, let me give you a little background on the way a TS808 clone (which is nearly every mass market overdrive since the TS hit the market) works. Inside your nifty little stompbox you likely have little electrical components called JFETs. These little guys are the next best thing for overdriving circuits in a natural way behind tube amps. Some people would even say that JFET's do it better, and there are several boutique and mass market JFET based overdrives on the market that sound phenomenal--tube like even. However, one thing that these JFET's won't do that a tube amp will is compress at higher gain settings--you need some other heavy duty components in the mix to acquire that property. So, lots of folks build what's known as clipping circuits into their overdrive designs. These circuits come in two applicable flavors: symmetrical and asymmetrical clipping, and they both lend unique dynamics to the overdrive. Asymmetrical clipping generates both even and odd order harmonics, and skews more towards even order the harder you clip. This results in a natural, smoother compressed sound with little to no intermodulation distortion--and sounds much like the push/pull dynamics of a tube based amplifier. Symmetrical clipping tends to emphasize the odd order harmonics and sounds harsher due to intermodulation distortion. The original TS808 used (and newer reissues still use I believe) symmetrical clipping.
Now, with all that history, if your GT-3 enables you to configure any of these parameters on your overdrive patch, you should play with them. If you want cleaner sounding overdriven tone then consider an asymmetrical overdrive or tossing a compressor in your chain (software or hardware). Also, if you have your amplifier gained out any whatsoever, you should remix the amplifier distortion and the stompbox distortion. It took me a month or two to find the proper overdrive mix on my rig such that my Orange didn't sound like a muffled, nasty, pissed off bass cabinet. Also know that all TS808 clones and most digital drives hike the middle frequencies. They do this for two reasons. First, bass frequencies sound blatty distorted--so most overdrives will cut those before they gain the signal. Second, high frequencies sound glassy and harsh when overdriven, and will sometimes get lost in the mix--so those are cut a little bit too pre-gain. All this results in a muddy mess.
Here's neat piece of information that I learned from Paul Cochrane of the Tim/Timmy fame. If you can control your bass frequencies pre distortion, and your highs post distortion, you pretty much have all the control you will ever need to get very nice overdriven tones. You can roll back the bass to reduce the blattyness to your preference--sometimes called "tighter" bass response, and then increase the highs to cover the mid bump and get a nice fat creamy awesome overdriven tone. Or jack the highs even more to cut through the mix during a solo. Very few newer boutique and mass market overdrives take advantage of this mostly because they are going for the TS808 vibe--which is dirt cheap and easy as pie to build.
Anyway, hope this helps. My overdrive tone quest has taken me years to arrive at a sound I'm happy with, but I'm still not even close to being done :D.
References & Trivia:
In my experience, this is a problem inherent in heavy distortion. I'd suggest one of two things:
If these don't work:
I have been through maybe 25 or 30 different distortion boxes in my life trying to find the one that has the 'perfect' sound for me, and to be fair, it doesn't exist :-)
In saying that, I have managed to find ways to make the sound work. On something like the GT3 I find you can reduce muddiness a lot by scooping out more mid and low than you might expect before you get to the distortion stage and then roll off a little bit of the highs on the output if it sounds too harsh.
Backing off on the drive for the distortion stage also works well to keep dynamic range as well as giving a warmer, less muddy sound.
On my Line 6 (which is in the same market place as the GT3) most of the muddiness, if I want it, comes from the amp simulator - if running into a real amp make sure simulation is disabled.
As already mentioned, choosing your chords correctly will have a big effect. If you are playing rhythm guitar you really won't need as much distortion, and you can allow a more middle-y sound. For lead you will usually want more clarity, but that can be through more or less distortion.
I had this problem for a long time, after tweaking with it a bit I've finally got the perfect tone with no muddiness on my chords. You won't even need a compressor or EQ. I'm playing through a Boss Blues Driver and Fender Twin Reverb. Make sure you are using your bridge pick up, as the neck pick up won't be favorable for overdriven chords. Now, turn your volume on your guitar down from 10 to about 7-8. You will immediately notice a cleaner sound and that minor third won't get blurred out nearly as bad. Now, for the overdrive itself. For lead work, my gain is at about 2 o'clock/12. I turn it left to about 11 o'clock and I have completed the perfect overdriven sound for any chords(major,minor,7ths,sus,etc.) I can't speak for everyone, but with my particularly set up, this change produces no unwanted noise while still keeping the power and fullness that I look to achieve when using my overdrive.
Okay, here's a solution for this that I just discovered.
I've been playing with various methods of gain stacking. I found a good (actually, pretty awesome) sound with the Zoom G5. I simply pushed the signal a bit from the compressor to the "Extreme Distortion" they have in the unit. (It's pretty amazing. I wish I could find something like this in a real pedal.)
Then I push it into the "Exciter" effect. (I'm pretty sure this thing just boosts the top and bottom frequencies in some way, but I'd love to hear if anyone here knows of a unit that this compares to.
Now, this still left my sound a tad muddy in the mids. But the distortion was TIGHT. Not a lot of weird fuzziness (I don't like that in my tone.) And the artificial harmonics are off the hook.
I just didn't like the sound when I was playing rhythm. I could boost the lows, but it never had that punch-in-the-gut feel I was looking for.
But I just grabbed a Boss DA-2 - adaptive distortion - yesterday. I had a sneaking suspicion that this would be a solution to that "indistinct" notes issue that most distortion creates.
To be honest, I'm amazed at the sound on this thing. All notes are clear and ring out distinctly, allowing you to play full maj/min and 7th chords and get ALL the notes. It's phenomenal.
Now, since I want a much "heavier" sound, I played with gain stacking on this bad boy. THIS is tricky, since the Boss wants to carve up the sound and throttle the distortion on each note.
What I wound up doing was punching in a Tube screamer on it, and bumped up the levels (not the drive) in the Zoom G5 chain. I'm playing through a clean amp (strictly power) into a Line 6 4x12 cabinet.
I've got an HD500, a Zoom G5, and a Digitech IPB10 (the iPad one.) They're all looped, so I can basically just mix n match. Every so often I have to throw a gate in the mix to quiet things down.
What I eventually came up with is a really kickass rhythm sound that just feels incredible. The leads jump out because the Boss does an excellent job of balancing the note frequencies and volume levels.
The only thing I can't get are crazy pinched harmonics quite like the setup I had on the Zoom originally.
I can honestly say that if I could get that last bit of flavor in my sound, I'd be 95% to my personal tone "holy grail." (C'mon, no one gets 100% :)
A possible culprit here is the volume balance among the strings, and the voicing you are using. Adjust the pickup's pole pieces to even out the volume balance.