Hello ,
a few years ago , I build this tube preamp with old tubes from WW II . The RC5B is a so called "Napfroehre" ( I don´t know this name in english language ) and was used for radar ? applications .
Data are here :
http://www.tubecollector.org/rc5b.htm
The preamp has an input transformer 1 : 2 from old german studio amplifier V103 and a 4,5 :1 output transformer from Siemens . Power supply is in an extra case . The input connectors are mixed Mini Tuchel , LEMO and Cinch . Input selector is a 2 x 6 Elma and the potentiometer is from Alps .
Distortion is very low , nearly only k2 measured with my UPL from Rohde + Schwarz . Now a few pictures from this little preamp :
Kind regards , Alexander .
a few years ago , I build this tube preamp with old tubes from WW II . The RC5B is a so called "Napfroehre" ( I don´t know this name in english language ) and was used for radar ? applications .
Data are here :
http://www.tubecollector.org/rc5b.htm
The preamp has an input transformer 1 : 2 from old german studio amplifier V103 and a 4,5 :1 output transformer from Siemens . Power supply is in an extra case . The input connectors are mixed Mini Tuchel , LEMO and Cinch . Input selector is a 2 x 6 Elma and the potentiometer is from Alps .
Distortion is very low , nearly only k2 measured with my UPL from Rohde + Schwarz . Now a few pictures from this little preamp :
Kind regards , Alexander .
