I just finished spending about 8 hours, (really), tracking down the noise in my signal chain. This is a recurring theme and peeve with me; any hiss, hush, rush, rumble, roar, even the slighest pops drive me crazy. I've noticed my last couple of recordings were noisy, (again), and I vowed to get to the bottom of it. I traced back from my current rig setup and eliminated one thing after another. Changed cables, turned on/off pedals in different combinations. Turned on the overhead fluorescent lights, floor lamps, overhead can lights, turned off the printer; none of that mattered to the noise. I concluded at one point that the Boss RC-300 looper was the culprit, so I removed it altogether. Still had the noise.
So I tried the other direction. I took my guitar and plugged it directly into the Steinberg UR22 interface. Wow, still had the noise! Well, that settled it. So it wasn't even coming from my signal chain, it was emanating from my "guitar/cable/UR22" connection somewhere. Could it be the notorious Strat single coil pickups? Even though I have the newest American Strat with the N3 Noiseless pickups? So I got out the PRS SE 177 with Humbucker pickups and plugged it directly into the UR22. Still noisy! OK, so it's the cable or the UR22. I had been running the gain on the UR22 at about 12 noon. I tried running it at 2 pm, and of course, the noise got worse. I backed it off to 9 o'clock and the noise was gone. OK, so now I know that I can't crank the gain on the UR22. I tried 10 o'clock, and it was not noisy. Great! Then 11 o'clock introduced a small amount of noise, but tolerable. And I know noon is unacceptable. So I picked 10:30 o'clock for the UR22. Was this the entire solution?
So I then plugged my rig back together and tested the signal and, wow, at 10:30 I can have all the pedals on, including the RC-300, and the noise didn't go up. It was fine! Yay!
However, when I recorded a simple chord change and then listened back through Reaper, I saw that the signal was way down at -42db. Arghh, way too low! Not loud enough for a re-mix by a long shot. I need the signal to be up around -18db; at least -24db. So, back the pedals. Having just purchased the Strymon OB.1 Compressor/Boost, I kicked that on and dialed the Output Boost Compression knobs to noon each. Brought the signal up nicely in the mix, but not enough. So I slowly worked with the settings and settled on 2 o'clock, 2 o'clock, noon for the Output Boost Compression knobs. And, the noise stayed low and acceptable. So, congratulations to Strymon for creating a Compression/Boost pedal that gives me a nice bump in signal with no additional noise! The Strymon site says this about the pedal, and I concur: "OB.1 combines studio quality, beautifully transparent analog optical compression with a Clean Boost".
Moral of the story: Some might wonder "Can't you just use EQ to reduce the noise?" Well, those more knowledgeable than I have said the best way to reduce noise is to eliminate it at its origin. So take the time to work with the signal chain; use only high quality cables; use clean power; be very wary of any pedals that add gain (Tube Screamer is no longer on my board); keep the gain moderate on your computer interface device; buy a Strymon OB.1 to get clean compression and boost; be careful with some fancy delays and reverbs that may add noise, for instance, the Bloom setting on the BigSky is fantastic, but it will take any string noise, or just clean signal, and "bloom it up" and can create noise/hiss/rush sounds.
Oh, and one more thing: I use a pair of Sennheiser HDR 170 wireless headphones; these are about $180, so they are pretty good and very comfortable. However, they introduce noise! Even with a flat signal, (i.e. no signal), they have a rush sound and a pop; it's like they are waiting for a signal to come over the air and making noise while doing so. Instead, I put on a cheap wired pair of AKG K52's ($50 new), and voila, a lot less noise. So another conclusion: wireless phones are great for listening to music; for mixing and really intense sound engineering, go with a wired pair.