sfdr vs bfdr

[skypilot]

what's scoop on this---finally??????
what did fender change(besides cosmetics) when they went from bf to sf on deluxe reverb???
Some say very little... teagle and sprung say basically unchanged(added 2 capacitors) another said the only thing that didnt get changed was the the bias supply... i know about the pushpull boost,...thanks
http://img.thegearpage.net/board/images/misc/progress.gif

[Swarty]

The very early SF DRs were identical. A few months into '68 they got a different rectifier, a different circuit board to facilitate all wires above the board (increase production/decrease labor) and at least 3 added suppresor caps (to deal with the added noise of the new wiring scheme). The pull boost stuff came mid-late '70s.

[phsyconoodler]

The early silverface amps were basically the same as Swarty mentioned,but as time went on changes popped up.Cheaper pots,different rectifiers,different transformers and very poor lead dress.Then they got really silly with pull boosts and suppression caps,bias balance instead of bias adjust,diferent coupling caps,filter caps,etc,etc....
As they get closer to 1979-1980 they were almost unrecognizable inside.A mess of poorly routed wires,lots of band-aid fixes for oscillations caused mostly by the ill-informed changes.They became increasingly hard to 'blackface' as they got newer.
When bean-counters get involved in amp building everything usually goes to shit in a hurry.