The bottom line, though, after listening to many different pieces of music, other changes accompanying what sounded like improvements in clarity started surfacing. Upper mid and higher frequencies have become more sharp to shrill which doesn’t appeal to me.@broadstone
When you make changes like this, you’re dealing with a set of compromises and you may have upset the apple cart. I find that good solid state rectifiers are better because you can support heavy bass passages better since the power supply sags less. But I’ve also seen rectifiers affect the sound since often solid state devices can make ’diode noise’ (which is actually caused by a resonance between the inductance of the power transformer and the capacitance in the junctions of the rectifiers; this can take a bit of work to snub the noise effectively) which can increase the IMD of the amp (resulting in harshness). In this regard, the HEXFRED rectifiers are some of the best we’ve heard but even they can have noise issues.
FWIW, when you google Yellow Jacket rectifier, all the hits are a bit sparse on information. This leads me to suspect that they employ silicon rectifiers, which are the mostly likely to have noise issues. So I would not write off solid state rectification until you’ve done more research. In effect, trying the Yellow Jackets, not liking them and then giving up on solid state rectifiers is akin to trying out a tube amplifier, finding you don’t like it and then give up on all tube amps. There’s a lot more than meets the eye with rectifiers!