I have a harshness in my distortion sound that's driving me crazy. It seems so sensitive I can hear things I don't think should be amplified. When I just slide my hand down the wound strings it's super loud. If I muff the strings with my hands and blow on the strings you can hear the sound. I used to have an awesome crunch sound that others tried to copy and then something happened and it seems to be in every piece of equipment I have including 3 guitars different amps even headphones.
Sounds like distortion is doing it's job.
The distortion/crunch/overdrive/drive/fuzz effect is generated essentially entirely through compression; and the effect of compression.
What does this mean? It means every little "mistake", gets amplified by N-Fold. These aren't always mistakes, sometimes it's controlled feedback, sometimes it's greatly increased sustain, and sometimes it's the sound of your fingers screeching across the strings. That's just the way it is - in a way - you have to learn to play with it.
Learning to play with it simply is finding the things you don't like in your playing with distortion and adjusting for them. Using a teacher - especially someone in the room - to immediately notice what you are/not doing can be greatly beneficial and help with your end-goals.
But, you can also adjust your gear for this to (to a degree, experience and practice also help a TON):
- String noise can be alleviated with using coated strings quite well, Thicker-coating strings work better for this as they smooth out the ridges created by the winding around the core of the string. See Elixir's Polyweb (and similar) over their Nanoweb for this.
- Adjust for the frequencies. Harshness in the sound of the distortion can be adjusted on the pedal. There should be a "tone" knob of some sort on there (or multiples, in typical EQ bands) that act as a hi-pass/lo-pass filter. Dial the higher frequencies out of the sound and the string noise should follow it (to a degree) relative to the volume of your playing. The tone stack on the amplifier should also work well for this. Even the tone knob on your guitar. It's a simple low-pass filter in most guitars which can let these extremely high frequencies come out, or tame off a bit.
- Try using distortion with less compression. This usually means turning the distortion level (drive, or maybe even labeled "boost") down and getting less distortion overall. The compression is what is bringing out everything low in volume to something much louder (String noise from the hand, and just string noise in general).
- Consider a noise gate. Players use these for just this application. It's much like a "reverse-compressor" where audio signal is removed or reduced where it falls below a set threshold. You can set this threshold to be the level of your hands sliding across the strings, but that may be pretty high and sound "choppy" to your playing. Instead, this is a great fix for high-gain miscellaneous string noises as you explained with "blowing" on them while they're muted.
- Try different types of strings. Differently constructed strings can yield more or less string noise. Flatwounds (which are regular strings that are "smoothed" or "ground" down - most used by jazz guitarists and bassists) and Tapewounds (strings literally wrapped in a type of tape - most used by bass players) don't have as noticeable ridges as Roundwound strings which cause excessive string noise as you move your hand across those ridges. Either of these options will drastically change the inherent tone of the string though; so if you're still wanting bite with that overdrive; you will need to adjust for it elsewhere (amp, guitar, effects, etc).
Are you playing louder (in general) now? The louder you play; the more frequencies you'll start to hear, especially higher ones (See the history of a Bright Cap, and a Presence Control). Which will make them stick out more than they may have before.
The frequencies that can take advantage of this capacitor depends on the value of the capacitor but we’re generally talking high frequencies. As the volume control is turned up the bright cap has less and less of an effect until the volume is all the way up and the bright cap has no effect at all.
It is mostly used to add a little “sparkle” to the tone. I heard, somewhere, that Fender, back in the day, used to add them on a switch so that non-Fender guitars would be bright enough when played through a Fender amp.
The presence control, on the other hand, resides in the power amp stage. Technically, it’s a “high frequency shelving boost” control, which is much like the treble control on a traditional stereo. Turning it up actually does boost part of the frequency band.
Since it happens in 3 different guitars, a few amps, and even headphones I would think that it's not entirely gear-related. It more than likely is your ear sensitivity getting higher for guitar frequencies.
Distortion usually involves overamplification of quiet sounds. I suspect your hearing to have gotten more sensitive: cross-check with recordings.
That does not mean that it would not make sense, now that you hear the noise, to adapt your technique, like trying to move position without putting pressure on the strings.