Stereo Mic Tube Preamp, Super Fi modified for audiophile tube preamp -(higher gain/lower noise, tube, eq, pad, RF PS, mic front preamp mods). All in one Microphone preamp, Harmonic Enhancement controller, tube compressor design. The ART PRO MPA when fully modified is $990. It is truly still unique for some of the clever adjustment capabilities. The most obvious is the ability to adjust the level and phase of a very euphonic second harmonic distortion which is then gain rided. The preamp can sound thick, punchy, dense, edgy, silky, warm, strident, etc. It’s not just equalization… it is an alteration and enhancement of the original audio signal....read more about it here.