Easy drive by 2A3/45 Single Ebded Amplifier Dr Joaquin Chile 2010 Apr
2A3/45 SE
New 2A3/45 Compatible SE
KT88 Single Ended Amplifier brand new on Sep 2011
Mr Tim Williams Plan of KT88 Single Ended Amplifier D.I.Y Step by Step from Australia
Sckematic showing
next very simple
circuit .DF is 2.5 ��depend on NFB EL 34 got power around 8 W to 9.5
W and KT88 is just like same power. 8.5 W and max power
is 10 W.may be
10W power get feel like destortion I am using cheap out put transformer
but sound like
very great.may be good for Cuerda like a chello.this is UL connection. this time use small
size power
transformer 320-0-320 and 180mA .so is not enough to get high power of
6550(KT 88).if you are obtain good 20W -30W output transformer for this amplifier. and good high
capacity of transformer such as 350-420V DC ,280mA DC. probably you may get
more than 15W rms at 6550/KT88 .this time i got 80mA at KT 88 cathode. should be choose 390 ohm
( correct cathode resistanse or fix bias use under negative power supply)
and plate voltage is around 370 - 420 volts better.meanning around plate current are more than 105mA
.when if you would like to get big power, necesary 2 stage driver.this srpp circuit is not
enough to drive high voltages condition.Power
tubes can be use EL34 ,
KT88 , 6L6GC instead of 6550.I will say sound of EL 34 Telefunken is beautiful sound
you can get and EL34 Svetrana too. coupling capacitor are ASC for KT88,
Vita Q for EL34 or any kind of oil capacitor and one thing SE ,
any SE are around 30%--35%(some time 25%) efficient from max dissipation
original tubes. depend on Auido out put Transformar and power supply
are good one.many old japanese builder choose 2 time capacity of transformer
so if would you like to get some 10W power out put. you need 20W output
transformer.It's Class A SE Amplifier.
And let's me tell you about minor distortion of amplifier.we call it's
"Cancel of distortion"from driver tube.if driver tube does not have any
distortion ,will be get major distortion out put stage if are using single
ended Amplifier.it's meanning diver tubes must be made up some distortion
for cancelation of distotion ofoutput tube(ex KT88 etc).any voltage tube amplifier
has 2/3 zone charactor.so startting position are always get non lineal distortion.what
meanning if you are using one of triode amplifier for driver .necesaly to adjust
load resistor for minor distortion of OUT PUT stage.please under stand,
driver tube is very important. if driver has good charactor does not
make good result on output stage minor distortion.so with your ear or connect
distortion meter with your amplifier then adjudt value of load resitor of driver.
if choose SRPP for driver . It is difficult adjust distortion at driver stage.
point of how to change sound: 1st decoupling of cathode capacitor are
using good Audio Capacitor like a MUSE NICHICON , Black Gate etc.
sometime use one of LED(Light Emitting Diode)instead of RC network.
please try to use LED decoupling element for 1st stage of cathode .
explane for Distortion ,please move mouse on the Icon.
Circuit is next.
this circuit is not original SRPP.we call it's "u(mew) follower for a little
more Gain than SRPP normal.
Diode are Kick Back Diode Diode: diode has
some effect ,some one call it's "Kick Back diode".protect
voltage
from your speaker.diode makes cancel voltage from voice coil.
please
try "connect diode "or "with out diode".with diode makes much power and
good response of low range.
and
you can hear something more ??.believe it's? if would like to test how
to function please try to use good diode some of over 20A diode is best.
some time say,Kick Back diode called as stopping diode,this diode can be use
any kind of rectifier diode.voice coil is shown above as L1 and this inductance
produce small voltage when speaker cone is moving,just like same kind of SW( Standing Wave)in RF circuit
signal is
going back from voice coil of your speaker system.so sounding and Df are a little
bit down with normal sound.D2 is old technic with RF power circuit.same kind of
Basically Fujii Amplifier technic.kind of D2 is best to use as same valves of Power tube
connected wired diode and get miner distortion than without D2 diode.
Just try !!! connected one diode on screen grid.you can get sound good.
Diode 2: Many peroson believe direct heating Rectifier tube
make different sound with
tube amplifier.
5V4G and 5Y3 if using , each tube has different charactor ,sound is very
different.
if your transformer has filament voltage please try to use Rectifier
tube like a 5U4G
if you do not enough voltage for 5AR4 Plate is better for use.274B
Golden Dragon is good when
I use the Rectifier tube for power supply.274B
Golden
Dragonis sound very nice bass.
even 5V4G too.if you can get easy 274B
Western Electric much better but very
expensive.
Rectifier tube has 3/2 charactor into your Amplifier.
KT88 Single Ended what kind of OUT PUT Transformer need ? In generally,KT88 SE 10 W means around 15 W(min)capability of Audio transformer
needed and power transformer is at least 170mA 420V from 360V for UL and Triode
connection or bigger.if would like to get more than 10W rms like a 15Wrms
at KT88 SE necesary 20W power output transformer.power transformer is around
250mA DC and Volatege is from 360V to 420V DC.impedance are form 2.5K to 3.5Kohm.
depend on connection mode.10W transformer means appx 8W rms max power.many Japanese
""hobbyst said 2 times out put power transformer use for single ended amplifier.""
and which is better with gap and without gap.with gap is very prety sound high range.
but with out gap is very low side are good.without gap transformer need some
compensation of high frequency range.with RC network etc.Valuve amplifier are depend
on Audio OUT PUT transformer.many people said "size of core".and should be use
Sandwich Wounded.
Most important thing:
If do you have good audio SE transformer with UL. please check frequency response with some
audio generator and AC mili meter.if did you get some ripple odd curve
on around from 40Khz to 60Khz frequency range means not good use for UL connection.
UL connection Amplifier will be oscilated some high frequency with all over NFB.
be carefull to use Single Ended Transformar.if transformar does not have a ripple and
ripple are over 100Khz. does not matter. but many audio transformar has ripple.be care full!!
even OPT-10S has ripple 40-60Khz zone.not good for UL penthode Amplifier with NFB. most 2 type of Transformar .one of EI core general and EI with gap U-808 ,XE-20S and many Tango's transformar are with gap and EI core.but some
Transformar like Harmmond transformar are general EI core.EI with gap and EI
with out Gap are just 2 different tone has.and many with out gap EI transformar
has some ripple on around 40Khz from 60Khz. Harmmond and Touei , noguchi transformar
has some ripple in high frequency range.what is meanning ? probably will be get
some oscilation with UL penthode when if used over all NFB.be carefull to use
with over all NFB.these are charactor of EI with out gap.but with out gap
transformar are very good low frequency response.many D.I.Y Transformar are almost
with out gap transformar. gap transformar is generaly good response on
high frequency range.James Transformar are material Japanese and Made in china.
many american and canadian Transformar are EI with out Gap .probably thay has
ripple at high frequency range.even some high cost europian transformar too.
many transformar type B and type A is Japanese Transformar I Knew and recommended
Tango,Hashimoto(Sansui)and Tamura.even some small transformar factory made too.
please see first frequency response of Transformar if did you get.it's not price
of transformar.some cheap transformar made good and sometime very famouse transformar
does not have good curve.meanning no use for Single Ende Transformar.be carefully
to use SE transformar.
one thing KT88/6550 Load Impedance is depend on high voltage low current
or high current low voltages.so 2 type of impedance.this is not only KT88/6550
valves low and depend on typical amplification mode like a Class A, Classs AB
etc. some one would like to use 2.5K so should be use high current and low voltgae
for plate.some one would like to use triode mode, should be use 3.5K or more
(like a 5K load)and voltages is high ,current is low.so G1 bias is high.thoes
things are depend on what kind of amplifier would like to build.
and size of Single Ended transformer is twice(or more)size of Push Pull
Transformer,so if 10W SE transformers core can make 20W push pull transformer.
small transformer never can get good low response depend on Material of core.
If do you have interesting more "study" for load impedance please see
study site like a please see it's**
Very good "Study" Site from "Valve Wizard from UK"
How can I use valve for Amplifier How to use all about valves
How to caluclate Power and self Bias ?
ex) EL34 how to caluclate Power,distortion and Self bias
so how to caluclate EL34 ,bias and power.
first pluease seek EP-IP charactor curve where get from some data site
like Duncan,K7 site for valves.
just exsample is for EL34.B+ is 350V ,Ib=72mA .point of S is -26V passing 3.5K
load resistance .point A is Ec and 0V, S is point of bias and point of B is
-26V X 2 so -52V lower side.always need charactor curve for calclate
value of valves.we always decided to calclate proper value when start build up
an amplifier.any valves can use any load impedance but have to caluclate each
time. Peak power get when grid reach 26V peak.so RMS value is 26V/1.414= 18.4V rms
so you need 18.4V rms signal into control grid.cathode bias resistance is
Rc = 26V/72mA= 361 ohm. wattage is 1.8W , you have to seek some 5W resistance
for safty.many time use cathode resistance are 390 ohm and +B is around 360V.
when are you would like to work as EL34 triode connection.triode connection
means many time use load impedance is around 3.5K ohm.so you can caluclate
easy for penthode condition.but one thing very importat is audio transformer
is enough to use for Single Ended Amplifier.which do you have.
tsearchesearchrh Hotladiesguide osearchs Wabo x Guide 2searchh Hotladiesguide tasearch.se Hot %search0 Ladies osearchm Places isearch.hao.sex%20hotmail.comosearcha
lsearchc Hot mh
N Places o Places s Cantina asearchc Nao chao.sex%20hotmail.commN Hot P
SsearchPsearch searchi Places hsearchF
u
nsearchysearchW Ladies dsearch Cantina a Guide d Hot DC