Please bear with me here; I'm a composer with decent composing chops but still very much a student of recording and mixing. My problem is that I'm getting noise on the recordings that I make of my compositions, which are all recorded with virtual instruments. This has been a problem only recently; I'll explain why later on. To try to fix this problem, I did an entirely digital recording (bouncing some virtual instruments directly to audio via the freeze track function in Digital Performer) and recording the rest live via S/PDIF from my PC. I both cases I bypassed my mixer. But unfortunately, I was still getting noise. Really confounding. I know that part of the problem is improper gain staging, and I'm currently working on that. But I also worry that the noise could be coming from some component in my system. Here's my system. I've configured it in a way to get the cleanest possible sound out of it. Digital Performer 7.24 on a desktop MAC. two PC's with EWQLSO on them. The PCs have Kontakt 3 as a standalone. I send MIDI to the PCs. The audio from the PCs goes out via S/PDIF to the interface on my Mac (an M-Audio Firewire Solo) and into Digital Performer. From there I may use some plug-ins to enhance the signal (reverb, delays), though generally I don't add much. I also use plug-in instruments on my Mac (Omnisphere, Superior Drummer, etc). Those I can bounce directly to disk via the Freeze Track function. I'm learning about gain staging, but I'm also a bit confused about it. I'm trying to see just how strong or weak my signal is coming into DP. It seems to me that the measurements of a track's signal can really vary from one bit of software or hardware to another. For example, on my PC, Kontakt has a master fader that can indicate a signal's strength. The audio interface for my PC (an EMU 0404) also has a mixer that indicates the audio levels. This interface also has all kinds of possible routings that I've never really messed with. Over on my Mac, the Firewire Solo has a mixer that indicates input and output levels. The tracks in DP have their own level indicators. Sometimes I'll insert a plugin that seems to give a more accurate reading of the signal, such as Sonalksis Free-G. So how do I tell how strong a signal really is? All of these faders / meters can have different readings. Some context / history (and I know you're going to cringe when you read this, but ... I'm trying to get better!): Up until now, I've had a slightly ridiculous system, but it seemed to produce tracks that were adequate for what I was doing. I sent MIDI to the PCs. The PCs would send audio out via analog, into my Yamaha MG 12/4 mixer. The stereo output of the mixer would go into the Firewire Solo. The audio would then go into DP. I always recorded at 16-bit, generally at pretty low levels. I would almost always boost the audio after recording inside DP, using the Free G trim. I tried to get it at about -12 dB. Why did I go through the mixer? Well, the Firewire Solo has only one S/PDIF input, and each PC (I have two) has a SPDIF output, so I just decided to stay analog. I also had other components that I routed through the mixer: Kurzweil K2000, Yamaha S90, and occasionally some mics. I've scored lots of short films and some video games and have written some production music. No one has ever told me that there was noise on the tracks. Occasionally people have asked me to give them a louder track. Now a producer with whom I'm working has complained that there is noise all over my tracks. The latest tracks (recorded digitally) were recorded all quite a bit louder than the previous ones. I know that he is boosting the tracks considerably. He says the noise sounds more like it's coming from a cable. I could barely hear it when I was recording tracks via my mixer. When I switched over to SPDIF, I couldn't hear it at all! Could the noise be more audible now that I'm recording in 24-bit? Could the noise be coming from one of the PCs, even though the signal is going through SPDIF and not through the mixer? I'm also wondering if it might be the Firewire Solo that is the culprit. I've thought about using a noise-reduction plug-in, but others have discouraged me from doing that since they believe those to be ineffective. I'm trying to take the first step in remedying this by getting a good gain structure, but now that I'm working with SPDIF and not the mixer, it's a bit confusing to me. So any suggestions you have about 1) how to get a good reading on the signal coming from the PCs and 2) how I might troubleshoot to find what's causing the noise would be very much appreciated. Thanks!!