Preamp Recommendations?

[CDMC]

not sure it will be so easy. The tube mode involves a warmup period, and the gain on it is significant to where doing a back and forth will be difficult. Add to that the volume clicks from the stepped relay volume, and it's really not going to be a good blind testing vehicle.

Benn there done that, and not the easiest as you say. It required using rew to measure pink noise levels, post it notes cut in a small arrow to mark volume knob positions, then getting up to switch modes and volume each time. Also, the Freya + is not a very tubey preamp.