When building say a fuzz face using SI transistors does the hfe of Q1 and Q2 matter like when using germanium? When using germanium I've read Q1 hfe should be + - 75 % of Q2 but does that matter when using SI transistors ? Or is that why there are trimmer pots in most SI fuzz faces to get collector of Q2 to proper voltage ?
IMHO, the relative gains of Q1 and Q2 matter with Si as much as with Ge transistors. Same Hfe targets apply, and as well as the same ratios.
Ideally you want both the correct ratios (Q2 50-75% higher than Q1) and the trimmers to fine tune it. The trimmers don't compensate for the difference in hFE, that's a completely separate thing.