Hi, i’ve got the Ribbons inserted in the send/return of a Quad Cortex and i’m experiencing clipping problems (bypass led turning to red). The Ribbons is right after an H90, which doesn’t clip (no red on this one). Outs on the H90 are set to Inst level.
To avoid clipping (especially caused by low end) i’ve got to lower the send on the quad (normal since it’s line level) but way too low (like -20dB). Another thing that solves is to change the input level of the Ribbons to SISO line level (helps a lot to keep a more acceptable level on the quad send) but i don’t understand the point. Could you help me to understand this ?
Ribbons uses an audio converter, and like any converter there’s a limit to available headroom. Instrument Level is essentially unity gain and is intended for typical guitar-level signals, staying clean up to about +3dBu (hot pickups and loud strumming might hit -13dBu to +0dBu, so plenty of headroom for a guitar). In a Quad Cortex send/return, especially coming after an H90 (harmonizers and low end heavy patches can be deceptively hot), the level can easily exceed that, so the input clip LED can go red unless you pull the QC send down.
That’s exactly why Line Level exists. It pads the converter input for more headroom (less chance of clipping) and then applies makeup gain on the output. The tradeoff is more headroom, but a slightly higher noise floor than Instrument Level.
So in your chain, Line Level is probably the right choice. Instrument Level is best when you’re feeding Ribbons directly from a guitar.