Audible Illusions modulus 3A, what would be the next level of up grade?

I would also recommend checking out the Calypso. I am using one currently after owning an Audible Illusions L-1. I would not describe the Calypso as noisy. They did have at one point a batch of noisy tubes sent out, so that may be the issue. I am still getting used to the sound, but I would say there is a texture to the sound, that may not be as “clean” as the AI, but somehow is more organic, with weight to the music. Imaging is also improved. It is definitely worth a listen.