I am starting to try to figure out some hiss issues with integrating my pedals + modular. I am curious if there are solutions that will help me achieve a higher SNR than my current system.
My euro (intellijel 7u) has a low noise floor. I can do loopback from my computer (RME out -> MI Veils -> Mannequins RIP -> RME in) and achieve consistently over 80dB SNR. Noise floor is about -100dB signal going out around 0dB peak and coming back -20dB peak.
Pedals are okay in loopback by themselves in a similar loopback configuration (RME out -> Meris Polymoon -> Meris Mercury7 -> Elektron Heat -> RME in). All pedals use their own PSUs, hooked to a power strip under the pedal board. I get ~65dB SNR. Noise floor is -85dB, signal again going out around 0db peak and coming back around 20dB peak. I will note the Heat can have a higher noise floor when pushed, but I feel like that is too be expected somewhat as they are analog saturation circuits.
When used together is when things get more noticeable. In loopback (RME out -> Veils -> Intellijel Pedal I/O Send -> Meris Polymoon -> Meris Mercury7 -> Elektron Heat -> Intellijel Pedal I/O Return -> Veils -> RIP -> RME In) I get a maximum of about ~50dB SNR (Noise floor -80dB, signal going out 0dB and coming back -30dB).
I am curious if there are things I can try to improve this. Can other things like impedance mismatches going in and out of the pedal i/o be part of the problem? Could power be causing issue (I am using a Furman SS-6B filtering strip but it’s not like a fancy conditioner or anything). One thing I have thought of is running the pedal loops independently in and out of the interface and routing them serially in the RME software. That will probably introduce a bit more latency, but I think that is okay for my current use case. The only real issue there is that it will max out my analog I/O on my interface and so I will not be able to monitor with my current setup.
UPDATE: I’ve been thinking about this today, and was thinking about how my method was doing several steps up and down from modular to line to interface with the pedals. I tried to minimize this, and sure enough I can get pretty close to a -80dB noise floor. The chain I’m currently using is RME out -> Meris Polymoon -> Meris Mercury7 -> Elektron Heat -> RIP -> Veils -> RME in.