D'après North Coast music, ils auraient été utilisés dans les AC30 jusqu'à 1967, puis remplacés par des Fane à partir de là.
http://www.voxshowroom.com/nor(...)b.htm
Edit : 68/69 serait la date de fin d'utilisation des Silver, d'après les infos glanées là :
http://music-electronics-forum(...)8024/
Et de vintage amps :
"As Don said, they are later silvers...second generation; there was a third generation in late 68 early 69 that had flanges in each basket hole vs. only in one basket hole for the seond generation. You often find third generation silvers on v1143 Beatles and Series 90s amps
The first generation had no flanges, terminals on the basket leg and three screws, as Don noted....and they were a darker gray vs. silver."
"Yesterday today was tomorrow and tomorrow today will be yesterday"