300B WE 300B Single Ended Amplifier D.I.Y

this counter started 1st Mar 2012

Please see with Firefox better see on your PC
Real Audiophile no use Push Pull Amplifier
WE 300B Single Ended Amplifier with James JS 6123HS

If would like to build up good amplifier please use Japanese Audio Transformer.

Much better use Japanese Transformer of waste of money for buy cheap Chinese Transformer

Flag Counter

This counter started on 1st June 2015

Version Japanese

Western Electric WE300B

WE300B is only Western Electric not from China

Western Electric Site

Takumi 2021 Feb

Takumi 300B on 2021 in Lampa Chile

Plays Tomomi Concertiste Mizushima 300B Single Ended Amplifier


easy build up CD type RIAA for Record player LP

2020 Mar

hifiberry and 300B Single Ended Amplifier on 2020 lampa chile

300B Single Ended Amplifier

WE 300B Single Ended Amplifier with James Transformer

Schematic is next, very clear sound and more powerfull sound I am getting.
casuse of 3 Stages Amplifier.from low frequency to high response are so nice.
I am using FE86 philips old type of FE86 with mesh plate for input line.
in generaly I am using for Main Amplifier at home from 2004.2 stage of 300B SE
with SRPP drive is a little bit difficult push low efficiency speaker like a my
System NS 300(90db/m/w).but this type of 3 stage amplifier is easy to push
low range.I like 300B with James JS-6123HS. Built up early 2004.
Actually ,,still using this 300B Single Ended Amplifier ,,EF83 + 6N1P + 300B EH ..enough ..good bass and mid and high is very clear.
and position of load impedance is 2.5K and I connected 6 ohms speaker 91dB/m/w so equivalent load impedance is around 2.7K ohms.
plate voltages 420V respecto with ground. coupling capacitor are Del Ritmo Vita Q ,low cost capacitor but getting sound very natural.
Max Power is 8 W rms.nominal power is around 7 W rms. much better than 2A3 but I like 2A3 sound from medium Efficiency speaker system.
Note: Single-ended amplifiers have low output power and require high efficiency speakers.
The efficiency must be at least 91dB/m/w. A full range of 96dB/m/w or better is good.
Some people use a horn type speaker with 100 dB/m/w. Choose high efficiency speakers instead of expensive ones.

300B Single Ended Amplifier with James JS6123HS

James 6123SH

please comparare with some Tango Transformer,James Transformer is narrow BW

tranformer terminal are assigned counter clockwise.so easily find which is primary and secondary.

Good Japanese Transformer

Why Japanese Transformer are good !!!! much wide than any transoformer :FE12 Tango


Hashimoto H20-3.5U

This is H20-3.5U semi universal audio transformer USD $ 600 dollars pair


PMF15WS Budget Transformer Noguchi USD $ 230 dollars pair


James's band width is not wide range, please compare with ISO Tango Transformers.
price is almost same as XE20S but technology does not reach level of ISO Tango Transformers.
if would like to buy James Transformer please see Tango XE-20S and Hashimoto Transformers,
much better for use single ended Amplifier.even FE-12S ISO Tango is good transformer.
often using Touei Transformer for Test and Kasuga Transformer too and budget transformer.
charactor are not so bad,both are small transformer maker.but get good quiality product.
one thing only making small power transformer.

this time a little bit change few things then changed upgrade sound getting with JS-6123HS.
choose 2.5K ohm impedance much better than before.not so bad sound getting from 300B SE.

Recommended Audio Transformer for 300B Single Ended Amplifier:

ISO Tango :FC-30-3.5S,XE-20S,U-808,FE12S,S-2595(40W 2.7K),S-2197(20W 1.5K)=FE-20-1.5S),(Tango are change impedance
secondary tap for universal transformer.a couple years ago quite.but 2016 started again.

Tamura : F-2007,F-5002,F-7002,are almost max 8W and high price.F-5002 is good.
Recently Tamura has new line fpr Single ended amplifier.each one 's weight is 5 Kg.very heavy.
: F913、F912 and F915 are new .very reasonable price but max power is only 8 W.
Hashimoto : H-30-3.5S,H-20-3.5U(2.5K/3.5K 20W)(Hashimoto's transformer are change impedance at primary)
Noguchi Transformer.Noguchi does not have factory but big company made for Noguchi.PFM-15WS (15W)is good.
very nice transformer for single ended amplifier.

300B Spec

WE300B Single Ended Spec table

300B SE + DAC 24bit 2012

EH 300B SE and 24 bit DAC on 1st Mar 2012

Then next circuit is version up circuit on Jan 2012
first stage is ECC82(Ecc802S),12AU7 and 2nd stage es 6N1P or ECC88 then 300B.
much better sound getting from 300B. future I would like to replace other MFG Audio Transformer.

I did small up date of my old 300B single ended Amplifier.
frequency response is 20Hz to 75Khz at -1dB non NFB and 20Hz to 85Khz at -1dB with 5dB NFB.
sound is not so bad than before,more clear and good frequency response which using 2.5K .
Power is 7 W rms. must be use fix bias for more power.but 300B tubes are expensive so
does not need much voltages and power for one's pocket money.that's enough.
some day I will try fixed bias for this 300B single ended amplifier.
coupling capacitor are using Tone Factory Vita Q paper oil capacitor.
sound is very good clear tone from Tone Factory Vita Q.I recommended to use single ended amplifier.
this amplifier using KOA resistance.will be replace AMRS resistace at all.
resistance AMRS are good and good C/P has.just quater of price of AMRG but sound are very good.
there are carbon corted resistance.AMRG is also carbon and surface around tube of alminum then
corted by carbon painted. sound is very good low to high range.AMRG is about USD $ 3.0 dollars
in Japan slightly expensive resistor.AMRS is USD $0.6 dollars in Japan.
economy but sound is just same as AMRG.what kind of resistance is good ? Skelton and
Z201 Vishay resistance are very high cost but very good.

all signal resistor are replaced with AMRS and some parts is AMRG.
so what is matter with this amplifier sound ? very clear sound and female voice is
more feminin like and Pianos touch is very real now.this is carbon resistance sound.
But does not get low ranges, this is world of audio.sound is very clear but does not get low.
I will be back to Matal corting film resistance by Takman Electronics co Japan.
TDO Metal
Takman Matal film Resistance(REY) by Takman and web site is Takman Electronics Co Japan
show above picture is Takman resistance, very budget resistance but sound is best for me.
to get much low range and mid /high is so sweet sound.REX and REY are for Audio resistance.

and this is Metal film resistance RSN1S TDO resistance

Charactor: Sound is good low ranges and good high range . if your amplifier does not get good low(Good Bass).
please try to replace of all resistance of Metal film resistance. You will be get good Bass and high frequency
tone. famous resistance are "KOA metal film MOS1/2C " "Vishay Metal film Z201" "Skelton Fukushima-Furaba"
"TDO, Solist or Takman Metal film" "Vishay MBB0207-50F" "AMRA" "Rikyu RO-25CFK"
"Vishay RN65D" "Takman RLF" "Tokyo Koon denpa RD" "Nikkohm solid resistance RP" "Alfa Electronics FLCX"
"Vishay VSR" "Takman REY" etc etc.

so recently I like sound of "Takman REY" and "Takman RSN1S" to get good bass from
my single ended Amplifiers.Nikkohm RP are good too.
REX and REY resistance Takman

REX Takman Resistance Co Japan

Nikkohm Matal ResistanceNikkohm resistanceuse for High End Audio and RF

so Resistance change sound of your Amplifiers.
probably the carbon resitance are good for pre-amplifier and some parts in power supply circuit.
how about you ? please try to use different resistance into your amplifier D.I.Y

Altec A7 + 300B Single Ended Amplifier by You tube 2016 Aug

Just show , 300B Single Ended Amplifier

WE300B and Amplifier

Western Elctric WE300B Single Ended Amplifier

WE300B 1998 model

WE300B Single Ended Amplifier

Cetron 300B

Cetron 300B Single Ended Amplifier

with Cetron 300B single ended Amplifier

Cetron 300B Single Ended Amplifier

Rechardson Electronicsas Cetron

Powerfull 300B Single Ended Amplifier

same circuit can be use for 300B,45 and 2A3 Single Ended Amplifier

300B/45/2A3 SET

Same circuit can be use for 45,300B,2A3 for Single Ended Amplifier


few components replaced will be use other type of tubes single ended amplifier.

EH 300B Single Ended Amplifier SPL 91dB/m/w (using fladance mp player) take long time for down load!!

Natalie Cole sing by PSVANE 300B Single Ended Amplifier on Jan 2019 shematic is same circuit of Takumi

EH 300B Single Ended Amplifier 2 type of Music (using fladance mp player)

Plays Diana K by Raspberry Pi B+ and Volumio 1.55 ,DAC is I2S PCM5102A and James 300B Single Ended Amplifier

DSD 2.8 Mhz coverted Dop (PCM) ,I2S DAC is very easy to build up by You.

How to get high voltage from low voltage for 300B single amplifier B+

how to get high voltages

Recently many Diyer using this kind of circuit .for getting high voltages from low voltages wind of transformer.
just circuit so if try to test this circuit please test cut and try.will be get high voltages easily.

One of hint for 2A3 and 300B compatible Single Ended Amplifier DIY

About circuit diagram ,,show next

schematic diagram

2A3 and 300B Compatible Single Ended Amplifier circuit

This circuit is just design for Dr Tim Williams in Australis. he made it's and good results.please see Note of how to make one of single ended amplifier.
His Audio System DiY A to Z ,He is using James Transformer for 300B and 2A3. please visit to see.
and just one of idea for compatible amplifier for filaments circuit shown next

5V and 2.5V circuit

Note: I am using EH 300B in general.some time using WE300B and 300B Cetron when some visitor came to house. always using EH 300B. impedance is 2.5 Kohms.
3.5K is very histeric sound of girls .so 2.5 K is much better than 3.5K when connected 6 OHM speaker system.sound is soft and much bass before.
many person said Sheungwan 300B-98 is best. so I have some money I will get one pair of 300B-98.
other one is ,,Akihabara in Tokyo best sold 300B is 300B JJ .many audiophile said same words. 300B JJ is good sound stage.
without expensive 300B tubes.300B-98
and Keiko(NGG) 300B is good.how about ? and what do you think ?

Plays Jazz by Raspberry Pi B+ I2S PCM5102A DAC on 1st June 2015

How about use for sound source from Raspberry Pi B+ This is not toy..High End Audio

Raspberry Pi B+

300B Single Ended Amplifier


My amp production is a product that is produced by prepaying Audiophiles all over the world. We are making and testing with all your heart
Such an amplifier can not be manufactured only by my income. It is a garage maker established by the act of the production client. Please understand it enough
The price of the amplifier costs at least USD $ 3000 dollars. This includes amplifier parts, hassle, and shipping costs is never a profitable job
80% or more is parts cost and use very expensive Japanese parts. The quality of parts made in Japan has fallen and not necessarily made in Japan.

I brew -Hand Made Single Ended Amplifier for you_PRICE LIST of AMPLIFIERSmiz

Western Electric Wsetern Electric Co USACo Still here

Good Bass , mid on 2016 May

HC20-3.5U Hashimoto and 300B Single Ended Amplifier 2016

Hashimoto H20 3.5U 300B Single Ended Amplifier

Hashimoto H20-3.5U

This time will be use H20-3.5U Hashimoto Transformer for 300B Single Ended Amplifier 2016

Mr Audio from South Americain PeruMr Western Electronics

2016 Raspberry Pi Music server

Still using 300B Single Ended Amplifier with Raspberry Pi Volumio Music Server 2016

PSVANE 300B Feb 2016

PSVANE 300B with James Transformer 300B Single Ended Amplifier on Feb 2016

300B Single Ended Amplifier on May 2016

If would like to build up one of 300B Single Ended Amplifier ,very much stable on May 2016

Note: Driver used be use 6DJ8 family but much better use 6CG7/6FQ7 and 6N6P .6N6P is same of Sovtek 6H6N 4.8W dissipation of plate
please adj resistance .12K ~15K .but must at leaset need B+ 420 V.top of plate is 430V ~ 450V respect with ground.
2dry of Power Transformer need at least 360V( recommend to use 380V ~ 400V ) and until ~ 400 V.if you think high getting replace first capacitor of filter to minor value.
if would like to use with James transformer ,nothing problem to use.this circuit.Hashimoto H20-3.5U is very wide frequency response
from 20 Hz to 120 Khz at -6dB NFB. and Non NFB is 20Hz to 90 Khz frequecy response ,just like XE-20S of Tango.
if would like to use PT-220V or PT-220P even PT-220 .please ask dealer of Hashimoto about change spec of transformer.which are replace 0-4-5 3A to 0-4-6.3 V x2 wound.
there are very important ,because 5V AC can not make 5 V DC .4.8V if use shottky diode probably get 6.0 V so it enough to use 300B Single Ended Amplifier.
if use shottky diode will be get around 6 V DC then adjust some sires resistor for adjust voltage of filaments.
PT-220 Hashimoto can not use for 300B Single Ended Amplifier.if would like to buy one of Hashimoto,much better use local transformer at your local.
many small shop can make these kind of transformer for power supply.for ex some motor company, repair shop for motor.small taller repair's motor.
be careful ..... PT-220 Hashimoto can not use any Single Ended Amplifier for Direct heating Single Ended Amplifier which is using DC filament.
Hahimoto does not have any product of Power Transformer for direct heating DC .even Tamura , Noguchi(no own factory,only name).
so have to order to small company. one thing very important ,do not buy PT-220 Hashimoto if would like to get good 300B Single Ended Amplifier.

WE300B use

300B Single Ended Amplifier with WE300B 97 0n July 2016


Hashimoto(Sansui)H20 3.5U 300B Single Ended Amplifier + JBL L40 on Aug 2016 Santiago Chile


Altec A7 + 300B Single Ended Amplifier by You tube 2016 Aug


Altec A7 with Guitarist Chileno plays ,took on 3rd Sep 2016 by Mr H C

By Shuguang 300B-98 Mesh

Power transformer detail
Transformer asignment

transformer voltage asignment ,just you need this kind of power transformer

My Audio System

I like Direct Heating Triode Single Ended Amplifier


Tama OHM

Real Made in Japan for 300B Single Ended Amplifier

This product is New product from TAMAOHM Japan. they make only resistance .photo is 880 OHM 20 W wound resistance .
TRH Type and they has from 5W to 1KW products.type of product is "Power-type non-flammable paint-coated wire wound resistors"
Special made for 300B Single Ended Amplifier.each one price is 1300 Yen(Japanese Yen) ,sales shop name is Seta Musen.
in Akihabara Japan.if would like to make contact Mr Fukunaga fukunaga(a)mars.dti.ne.jp
(a) is instead of @ . a part of e-mail address.and Tamaohm 's Site is TAMAOHM .
for catalogue

ISO (ex ISO TANGO)is re-Started
ISO Transformers Japan

Started from 2nd OCT 2016 as ISO TRANSFORMERS CO Japan

they have FC-20S instead of XE20S only name of transformer is different.and Name of company is no more TANGO.
New company re-started by ex employee of ISO TANGO.real new company of ex ISO TANGO.and New Name of company is

I am using Kester solder for all amplifier of mine

Kester solder

As you know many guitar Amp maker is using Kester Solder for build up his Amplifier.
long time I am using this Kester Solder. LOT# W121307 .Kester USA why I am using?
because good.more than 10 years using this one.

2016 Nov 300B single ended amplifier

Just before Burn in 300B Single Ended Amplifier on 26th Nov 2016

2019 New 300B Kanade

300B Single Ended Amplifier on APR 2019 Name is KANADE

300B is very good valve,even China product QC is going up and PSVANE 300B 's sound is very close to WE300B made in USA.
and getting enough power at home.personally I like 2A3 Single Ended Amplifier with good audio transformer,but sometime
not enough power to get.first amplifier for one is EL84/6BQ5 Single Ended Amplifier.2nd Amplifier is 2A3 SET.then 300B SET.
these line are very useful at small room.

300B is Best

Very good sounding from 300B Amplifier on Jan 2017

300B Single Ended Amplifier Hashimoto

Schematic diagram is above and getting 9 W rms

And 2017

HO-808 Using 300B Single Ended Amplifier

Hatt Audio Lab HO-808 300B Single Ended Amplifier 20th Mar 2017

with Cetron 300B

with Cetron 300B just seem like original western 300B sound is great than EH300B

XE20S ( Hirata ) using 300B Single Ended Amplifier on Nov 2017

Encore by 300B with Hirata Tango XE20-S

Schematic Diagram is here ,, EF86 is very difficult to get country side so choose ECC802 in parallel

If going up voltage of B+ ,can be use 10uF 630V at first capacity of power supply after 5U4.will be get B+ 435 V .this transformer capacity is
400V x 2 and 280 mA.so if your amplifier 350V x 2 AC ,can be use 10uF 630V for going up B+ around 400 V.a little more power than 47uF 500V.
just try.

Solen Made in France

10uF 630V film capacitor for first cap for power supply

This Encore 300B Single Ended Amplifier ,replaced 5814A Sylvania instead of ECC802.very clear and getting tight bass than 12AU7 family.5814A is
one of family of ECC82/12AU7 but different rate of them .sound is very stable and thinking good for Jazz. Piano solo.Sylvania 5814A is good.

sylvania 5814A  NOS

first stage of 300B Eingle Ended Amplifier


In Santiago Chile on Feb 2018 with Altec VOT"he said very good match with ATC100 Speaker System

By YouTube,,,up loaded on 25th Nov 2017 ,ES9023 I2S DIY DAC Using 300B Single Ended Amplifier

which 300B Valve's Sound is Best

1 PSVANE 300B Made in China
2 JJ 300B Made in Czech Republic
3 Gold Lion DX 300B made in Russia
4 CCI 300B-98 Made in China
5 WE 300 B Made in USA 1997
6 WE 300 B Made in USA 1987
7 Takatsuki TA-300B Made in Japan
8 EH 300 made in Russia

It is based on the result of voting by 30 Audiophiles some day in Tokyo , it seems that it was "blind test" to exclude prejudice, so let's make a great deal of mind.
so most low price of PSVANE 300B is best to get good sound.I prefer too. actually I am using PSVANE 300B.sound is very good and enough to use my room.
and very much enjoy listen Music every day. very cheapest PSVANE 300B is best price and best sound.
WE 300 B is not necessarily good in the world.
I also feel that the sound is also clear and if used it sounds better. PSVANE 300B is a very good reasonable vacuum tube.

The LM78T05 5V 3A IC has been discontinued

I realized that I hadn't bought the LM78T05, but I thought it would be somewhere. I understood that I was not in Japan and I was asked by an IC importer.
If you check the distribution route, it turns out that there is no, compatible IC is called LT323AT. To be precise, it is a regulator of the LT323AT LDO. It is around 700 yen for 1 piece.
There was other compatibility. MIC29300-5.0WT ◆ The name is 3A, 5V. Therefore, two kinds were hit. I ordered several pieces because each store seems to have stock.

The first 300 B single amp in 2019

The power transformer has been made one rank higher. As you can see from the circuit diagram, it is 430 V even if the B + voltage is loaded. That would have increased the plate current.
The low range has improved considerably. I also feel the same feeling of power, I can create an unmistakable sound either listening to Jazz or listening to an orchestra.
The power supply transformer is a special-purpose transformer for general transformers and sales stocks. The price was also reasonable. I have not measured it, but I think it is within the rating. Various until it produces a result
I tried a transformer. It is change of the existing transformer and the power supply capacitor. The rectifier is 5U4. I was asked to wind 5V 4A from the request to use this vacuum tube overwhelmingly.
I do not understand only the sound of youtube below, but I feel that it is clearly improved when listening to modern music etc.

cocoliso v2 2019

big size of power transformer using new 300B Single Ended Amplifier on June 2019

Kanade 2019 June

Kanade 300B on 7th June 2019

Sound getting from NanoPi-Neo Music Server ES9023 DIY DAC on 7th June 2019

By Pianist Tomomi Concertiste sound get Kanade 300B

in chile

Mr Hugo's room in Lampa Chile on 15th June 2019


Hirata Tango XE20S made on 2018

cetron 300B

by Encore Cetron 300B picture came from chile .14th Aug 2019

The sound of these classic 300B tubes, which are a copy of the Western Electric and made in the USA,
is very similar to the Western Electric 300B: medium-range, high-definition range, with a touch of sweetness that does not affect the naturalness of the sound .
The response of the low frequencies is of great presence, perhaps more pronounced than the Western Electic.
The average frequencies go on the air with the same fidelity of the recording: if the recording is bad the sound is horrible, but with high-resolution recordings or high-quality CDs the sound is sublime,
you can distinguish even the different timbres of different violins , and even the timbres of the different strings of the violin ... is the extreme high fidelity.
With these tubes and this amplifier you have to have the entire audio chain with the same high quality. And if the source is not up to the tube and amplifier better forget ...
It is a privilege to enjoy vintage audio jewelry like these Cetron 300B tubes.
It is difficult to imagine that the musicality of the 300B tubes of the Cetron and Western Electric brands can be overcome.
Audiophile greetings,


Takumi 2019 chile

at home in Lampa Chile Takumi 2019

Kanade update version July 2019

on July 2019 update model of 300B Single Ended Amplifier.

Kanade 300B

Kanade 300B Single-Ended Amplifier on 30th Oct 2019

Kanade 300B in Chile

Kanade 300B on 30th Sep 2019 in Chile

Mizushima 300B Single Ended Amplifier Play Piano

This music use is with permission from the person.

300B Kanade parafeed drive Single Ended Amplifier on 2019 only circuit diagram

V3 parafeed 300B 2019 Nov

Parafeed 300B Single Ended Amplifier on 2019 Nov design (only plan)

Cocoliso 300B Single Ended Amplifier has new owner in Chicureo Chile by Mr Pablo Prado Nov 2020

so 300B cocoliso has new owner is very good things

His system with 300B Amplifier Speaker is Diapason Adamantes 6 Ω 91dB/m/w

The Cocoliso 300B has changed owners twice a times and eventually to Mr Pablo Prado of Chicureo, Chile, and about three weeks ago I received an email and asked for a picture
I received the image via email on November 30, 2020, and here it is. The speakers are made in Italy by Diapason Adamantes.he listened to them before using them.
First of all, I'm very happy with them. I'm sure you will take good care of it.

Nobsound mono 300B Single Ended Amplifier USD $ 1000 dollars

Recently I am doing repair Nobsound amplifier's for part time.this amplifier came from them Nobsound Japan for repair.just introduce you inside of amplifier.
quite good .circuit is same as sun audio circuit and triode.com audio amplifier 's circuit. looks very good ,inside is not so bad too, just show you inside.
then what do you think ? USD $ 1000 dollars may be out of Japan 's cost is a little bit high cost because shipping cost is not same.well I love these amplifier.

cocoliso 300B Single Ended Amplifier in Chile Dic 2020


Nobsound power supply circuit not an ordinary circuit


This circuit uses a diode bridge, which is very common these days. The rectifier tube is not used as a rectifier tube, it is just used as a damper for the voltage drop of about 60V. The rectifier tube is not used as a rectifier tube.
If you look at Amazon's website, you will see that the PSVANE factory in Shenzhen burned down last year in 2020, and they were unable to get good vacuum tubes, so they made this circuit as a result.
But the rectifier tube does not play the role of rectifier in this circuit.If use normal circuit and normal Japanese transformr will be come good amplifier.these thing is problem of Made in Chaina.
It's a shame, but I think it's a good amp for educational purposes.

Tested Nothing problem at all .only has problem of 300B valve was bad


MIC29300-5 Microtip Tech

LT323AT Analog Devices

blue note


mizushima 300B

Raspberry Pi B+



Hatt Audio

Hatt Audio Laboratory Japan --Audio Transformer Factory--

David Foster

Perfectus Audio from Queensland Australia show as friendship site link By Mr Ben Johnson

Go to pther side of 300B Amplifier


300B and 45 Compatible SET by SwitchJust plan for build up

HORN Speaker

211 Single Low High Volt Set

Soya WE91 300B SET

Show you Jeff's Place what they said

NewXE-20S Old Tango 300B Single Ended Amplifier 2017

Bifu V3 300B Single Ended Amplifier for 2017 HO-808 by Hatt Audio Lab

Cocoliso 300B Single Ended Amplifier on Dec 2016

Low Cost Model of Mizushima 300B for sale 2021

ELrog ER300B //From 2A3 SET to 300B SET modification

Vlave search

duncan amp


this is Youtube List for my site please viste


this is 2A3/45 Single Ended Amplifier Bohemia .owner live in Tacoma.WA USA 2021

Last Up Date 26th Feb 2021

Takman where you can buyREX out of Japan

Takman where you can buyREX from Acoustic-Dimension

Since 300B SE Amplifier circuit on July 2004 Sakura Chiba Japan

7th Avenue

©  Mizushima Audio Laboratory Japan 


How to build up Amplifier Single Ended Amplifier 2003 - 2021