As 45 Single Ended Amplifier from Chile with Passive Pre on 25th May 2014
Dr Joaquin from Chile,May 2015 DIY pre(DSD DAC incorporated)
Single Ended 2A3 of AmplifierISO Tango XE20S 2A3/45 Single Ended Amplifier
schematic circuit indicated next,this time use ISO Tango XE20S Transformer with
2A3 Single Ended Amplifier. 3 stages amplifier with SRPP Drive.
2A3 Single Ended Amplifier with Tango orient hi-b core transformer
2A3 Single Ended Amplifier on 1990
frequnecy resonse is within -1dB from 10hz to 100Khz at 1W rms
power is 3.5W rms, max power is 5W rms.I did finished built up 2A3 Single Ended Amplifier
input line are RCA of 2 line and one of Balanced input(Tamura TK-20).
Amplifier can be use both RCA 45 and 2A3. Audio Transformer are ISO Tango XE20S.
point of Test: voltage of +B is around 309(2A3)/320(45) V.Cathode voltage is
45 V for 2A3.plate current are 60mA each valve when use 2A3 Golden Dragon.
RCA 45 single mode is very nice both with NFB and non NFB.power is very low like
original power as 1.5W rms but feel like more than 2A3 single ended mode power.
RCA 45 are using 1936 USA Made but used.still getting good sound from him.
very good boy!!!. noise is around 0.8mV at non NFB position.
recommended use 2A3C or 2A3B china(Golden Dragon Premium) and EH 2A3.
and any old 45 valves.
convination of valves are EF86(telefunken,new tesla or EH)+6CG7(EH or Westighouse)
and any 2A3 made up good sound.+B of plate of 2A3 is 320V getting good sound.
2A3C sound is just like sound of RCA 45 and feel like much power than any 2A3.
very close sound of Sovtek 2A3(old).2A3C is very nice to hear any kind of Music.
very clear and good bass.2A3B(premium Golden Dragon) are good bass and clear.
one thing old chinese 2A3 are very cheap but grid wire are using gold wire.
sound is good too.one thing bad is physical problem inside of Glass painted after
few hour use from brand new valve.but sound is nothing problem.
2A3C is expensive in Japan and 2A3(B)Golden Dragon too. 2A3EH made up good sound
but I like very much sound of Sovtek 2A3. all new type of 2A3 got 4W rms non clip
Max power is around 5W rms.if give more +B for plate sound become a little bit
getting sound tight. 2A3 family is 250V and 60mA dissipation made good confortable
sound than high voltage of Plate.sound quality is depend on Audio Transformer.
2A3C is good .best valve but has physical problem inside of valve.some time getting
noise when cold started play music.still unstable product from China.
2A3C Sound is Best but have big risk.
Rectifier is 274B china and 1st filter capacitor is Sizuki 47uF 800V film capacitor for
getting good condition filterring ripple.big electric capacitor are Nichicon.special
Spec for valve amplifier.
2A3 JJ is not 2A3 .suppose be KR family too.
componets are next picture.power resistance are 5W kiwame and small resistance
3/4W AMRG non inductive carbon resistance.4 of cathode resistance are 10W Dale.
condensor are Nichikon,Shizuki and TO-ICHI.coupling capacitor are TO-ICHI Vitamin Q.
components: Teflon UX 4 Base and 2 of XE20S,chork,chassis,
Perforation of Chassis(Takachi SRDSL9-HS) 穴をあけたところ
Audio Transformer are XE20S but ISO Tango XE20SE.a little bit different charactor
with old type XE20S .old type of XE20S are more bass range is powerfull.realy only
4dB from NFB can get around + 1.5 dB more peak at 20Hz.high frequency range almost
same like ISO Tango XE20S.reach to over 100Khz with some NFB.I will remake 2A3/45
Single Ended Amplifier. same like above 2A3/45 Single Ended Amplifier.will be soon
here on WEB. Chinese Valve Amplifier does not made up good frequecny response.
Japanese Transformer are good.even" I was I Were Tamura"" but very expensive for
for my hobby. Power is 4 W rms( one side clip). DF is 2.5 and Max power is 5.5W rms.
and frequency response is 5Hz to 100Khz at -1dB -3dB over all NFB.0.5mV noise.
another think 2A3's C/P is very good.pair of valves cost less than USD$100 dollars
and Get 5W rms of Power. sound is very good.one thing better than 300B SE.
I never use Metal Clad resistance and Cement resistace. both are bad for rush current.
easy to burn with rush current.and both resitance are almost same type of elements are using
as resistance so not so good for valve amplfier.
I am using Dale non inductive resistance for Cathode resistance.
power resistance are Kiwame Carbon and signal passing parts are using AMRG resistance.
big size electric capacitor are Nichicon for High End Audio.and coupling capacitor are
Vita Q Toichidenki Japansame thing I said above.
TOICHI Denki Vita Q oil parper capacitor
in general use parallel with film capacior for High End Audio,I used 2 positon which are 1st
coupling and 2nd stage with final.0.22uF630V ERO film and 0.47uF630V Vita Q in parallel.
anti magnetic,low noise low distorcion carbon resistance for High End Audio
AMRG MFG isAmtrans Japan.
What built up for this 2A3/45 single ended Amplifier This 2A3/45 Single Ended Amplifier is built up for one of client of AUDIO AERO Capitole user,
and he has Altec high effiency speaker system.
he said super good tone has this amplifier which is connected with Audio Aero Capitole CDP with Balanced output.