why do expensive amplifiers produce a better soundstage

I was led to believe that, expensive amp's had luxuries like silver solder. Rather than tin-lead s**t. Why has no-one mentioned that?

@irjones 

Because it probably has negligible impact on imaging relative to other influences?

Surely, those expensive produce a better soundstage. However, this is not. 

The DIYer's do have passion in building the super amp with top notch performance. 

Adequate power to negate frequency shifts due to speaker impedance variations.  This doesn’t necessarily require that the amplifier be expensive but some things to look for are a robust and quiet power supply, adequate power for the sensitivity of the speakers being driven, and the ability to nearly double power into lower impedances, which is more critical when used with hard to drive speakers.

OP  expensive amplifiers produce a better soundstage

You should be aware that the soundstage here is only in the electronic unnatural sound world term. It’s not the same music we hear from recording studios or concerts. It’s a purely imaginary sound art. To non-a’philes, it’s just ear-hurting distortion noise veiling the real music. Alex/Wavetouch audio