Why do tubed preamps image better than SS?

No pre-amp images best of all...

generally speaking,tube amps seem to offer more 'front to back depth',while ss throws a larger soundstage... but in all honesty, speakers will make a bigger difference in 'realism' than your pre or power amp, provided the components are more than capable of driving them to their potential.

Mahandave
do you mean Lamm LL-2 or L-1 or L-2 or all of them ?

Imaging is a direct result of low-level detail recovery and proper phase reproduction. Low level detail is a thing that tubes do better because of their better linearity at the low levels in the area where things like ambience and the like reside. One of the direct results of this superior linearity is that tube circuits generally do not have to run as much negative feedback, and also have less stages and devices in the circuit. Negative feedack is easily demonstrated to reduce soundstage depth and width, and generally less stages of gain will result in less places for the signal to get screwed up.

Phase relationships tend to be similar in all preamps so long as bandwidth is a common denominator; good tube designs are capable of the same bandwidth as transistor designs so this is probably not the defining variable.

Atmasphere...Lower feedback in tube amps is usually because the darn thing becomes an oscilator if you increase it any more! (That's my experience). Also, are you forgetting the heavy feedback around the output transformer represented by the taps that are connected to output tube grids. (Of course this doesn't apply to triodes).