Preamplificatore RIAA per testine M.M

Nuovo Preamplificatore correttore RIAA completo, adatto ad essere abbinato a tutti i preamplificatori di Tiger2000. Questo circuito consente di utilizzare giradischi con testina M.M,per l'ascolto dei dischi in vinile su qualsiasi amplificatore sprovvisto di correttore RIAA.

Specifiche tecniche:

A phono input jack connects to the grid of a triode, one half of a 12 A X 7. The shield of the jack is grounded. There is a 47 k ohm resistor from the grid to ground. The cathode goes to ground through a 3.3 k ohm res. We will be coming back to this cathode later. The plate of this triode goes through a 470 k ohm resistor to plus 150 volts. A .01 mike cap goes from the plate of the first triode to the grid of the second triode, other half of the 12 A X 7. A 6.8 meg ohm resistor goes from the grid of this second triode to ground. The cathode of the second triode is grounded. The plate of the second triode goes through a 220 k ohm res to plus 150 v. The plate also goes through a .1 mike cap to point A. From point A there is a 3.3 meg ohm resistor in series with a 100 k ohm resistor to the cathode of the first triode. There is a .0033 mike cap in parallel with the 3.3 meg ohm res. There is a 750 pf cap in parallel with the 100 k ohm res. The positive side of a 1 mike 15 v cap connects to point A, the other end goes to the output. A 3.3 meg ohm resistor goes from the output to ground