Introducing 45/2A3 Single Ended Amplifier drived WE417A by Inter Stage Drive
shemactic diagram for 45/2A3 Inter Stage Transformar Drive
2A3 Single Ended Transformer Drived Amplifier
Order detail:use XE20S for Out Put and Driver Transformer are NC-20S
Tubes Base are Yamamoto Teflon Base.Potentiometer are Kohon Denpa CP2500
2A3/45 compatible single ended Amplifier. Driver tubes are WE417A or 5842S.
220V use for Indonecia. one input for un-balanced.6's Binding Post.
power supply use Black Gate condensors and MUSE Nichikon Japan.
wiring is OFC cord and some parts use siver rith cord.
Filtering chorke is big ISO Tango Chorke.first input line of power supply is
Shizuki 47uF 800V Film Capacitor and signal line of resistanse are AMRG.
Spec: 45: 10Hz from to 60Khz Non NFB and
10Hz from to 80Khz at -2dB NFB
2A3: same as above.
Power : 45 of Max Power is 3.0 W rms and 2A3 of Max Power is 7 W rms.not sure
probalbly getteing more power.45 are old type of valuves and 2A3 are old and
new type 2A3 can be use.off course you can use 245 family too.
S/N is very good and very low noise. Shotkey diode produce miner noise than silicon diode bridge.
I could not hear any noise from speaker.this time I got 4.1 V DC from 3.8V AC.
and 2.5 V DC 2.5A Got from 2.5V AC 50Hz.normally silicon diode bridge produce 1.7V DC
from 2.5 V AC and 2.5 V DC from 3.8V AC 50Hz Transformer.but if using SBD,
3.0 V DC from 2.5V AC 50Hz and 4.1 V DC from 3.8 V AC wound of Transformer.
2.5V for 45 1.5A using 2 serie of silicon diode added one of shotkey diode then
getting 2.5V 1.5A DC. 2 of silicon diode getting 2.5V 2.5A DC.
ripple is very very low than any silicon diode rectifire.so very low noise from
Speaker.I say , can not hear any noise from speaker.
2ndary of NC20F is open ,does not use load resistance.sound is very clear and sound
like good C coupling non NFB sound getting.Non NFB is good for Transformer Drive in
this case.1st I did try to use silmic for 1st cathode bypass but sound is dead so
replaced MUSE Nichicon Green type condensor.and 2A3/45 cathode bypass is added
other 470uF 200V. total is about 1000uF for cathode Bypass.please see circuit diagram
5842/417A plate current is 17mA and +B 185V at non NFB position.
Sound is very clear tight low and mid and high are very clear when using with WE417A only.
so 5842 can use but not useble for this amplfier.2A3 RCA is plays very good and very clear
This Amplifier orderd by Victory Audio ,Jakarta Indonecia. 13th Aug 2010.