Vermes
Advanced Member level 4
It is a phono tube preamplifier with RIAA correction. Housing and style were inspired by tube amplifier from here: LINK. Construction of this design was based on a single tube ECC83 in each channel. Supply of glow circuits of the tubes may cause 50Hz hum. It is good to symmetrize the glow and shield the tubes. Correction is implemented in passive way. System has a poor gain, but it is enough for driving the amplifier. There are additional electrolytic capacitors which shunt cathode resistors so that the gain increased and hum of glow also decreased.
Pictures:
Schematic:
R1= 47Kohm R7= 820Kohm C3= 22nF 400V
R2-3= 220Kohm R8= 27Kohm C4= 10nF 100V
R4-5= 2.2Kohm C5= 3.3nF 100V
R6= 1Mohm C2= 100nF 400V V1= ECC83
Sample of sound:
Link to original thread - Lampowy przedwzmacniacz gramofonowy z korekcją RIAA