Germanium investigations

[analog_sa]

This movie brings back memories of the hundreds of Ge transistors i have decapped. Some decapitations were done for science as it was an easy way to create a phototransistor. No idea why those were fascinating but i am sure they were. Other of the fallen Ge heroes were full of thermal grease which i used to squeeze mercilessly down to the last drop whenever a heatsink needed greasing. The cruelty of young age. At least i left snails alone.

 

[Soundhappy]

Imagine Ge's 2SB206 etc. green light curve traces show on the screen of Mr. MR Tektronix 577 Germanium investigations

 

[Soundhappy]

Curious what amplifier Mr. Pass friend swear about desirable audio germanium output power stage quality.
Guesses high level of expectations with such long audiophile experience.
Intriguing message

 

[Soundhappy]

Sziklai Germanium Transistor Leakage and Gain - YouTube

 

[OldDIY]

Anyone who has a pair of power Ge can listen to the 60x sound
Bias and co. in a 1960s SS amp Hohner Electra Piano
Amplifier Lin (RCA) with Shaw diode.
Усилитель на германиевых транзисторах Радио 1970 №2 Иванов - YouTube

 

[OldDIY]

Class A amplifier.
Германиевый усилитель класса А. - Усилители на транзисторах - Звуковоспроизведение - В помощь радиолюбителю

 

[Soundhappy]

@ Old DIY

Thanks for the links
Germanium from old Soviet Union are interesting semiconductors:
unique sound character and " build like a military tank " manufacturing quality.
Home made heatsink for small signal Ge on the photo.
Source : Простой германиевый усилитель мощности - Усилители на транзисторах -
Звуковоспроизведение - В помощь радиолюбителю

 

[OldDIY]

Amplifier without GNFB
Усилитель без ОС (3). Токовый шунт. - YouTube

 

[alexberg]

With all do respect. There are Ge transistors with decent frequency response. I quit using old МПхх transistors being 13 years old. Newer ГТ series are much better. I would doubt "the quality" of transistors mentioned, mostly used in Royer oscillators and linear regulators, made at times when the trees were high.
Try find like ГТ703/ГТ705 with ft of 10 kHz. Complementary pair. Really shines in megaphones.
http://forumimage.ru/uploads/20171030/150938171845856984.jpg
http://forumimage.ru/uploads/20171030/150938303618235764.jpg

 

[Soundhappy]

Ge transistors tests in proper class A circuits with the Audio Precision tool can bring a lots of aswers.

BTW one Shindengen 2SB206 auction Dissipateur thermique avec Sanyo 2SB206 transistor de puissance | eBay

Good luck

 

[vsmusic]

Phono preamps with germanium transistors .

 

[vsmusic]

...

 

[Soundhappy]

@ Vsmusic

Fantastic work! Congratulations
Could You write more informations about specyfications and audio performance ?
Best regards

 

[vsmusic]

Soundhappy The first product is an upgraded version of the 1972 scheme . Measurements using RMAA showed this result-the noise level is minus 73 dB . Harmonics - 0.044% . The measurement was made at the signal level at the preamp output of 2 volts from peak to peak . Gain greater than 40 dB . The product is powered by a VRLA - 24 V battery (2x12 V / 0.8 a / h). The scheme has a rumble filter .The indicator shows the signal level and battery level. The battery receives a charge from an external automatic device .... The sound of this product is good . I use it in conjunction with the Kenwood KP-770d player and the Empire Broadcast one cartridge .

 

[vsmusic]

Soundhappy - The second device is an upgraded Telefunken TV-206 scheme . One transistor is added at the output . The gain is about 42 dB . The noise level is minus 73 dB ( at the output of 2 volts from peak to peak). Harmonics-0.016 % . RMAA . Power can be supplied from an external stabilizer 32 volts .

 

[vsmusic]

The third device is also made according to the Telefunken TV-206 scheme . Differs from the second product - a different type of capacitors in the correction circuits . This copy was made for a friend of mine .

 

[vsmusic]

Preamps on germanium transistors provide a very good sound-three-dimensional, with a beautiful transmission of voice and acoustic instruments . I like these preamps . I have been using one of them for about 5 years . I have preamps on both silicon transistors ( BC149C / BC550C/ BC560C) and JFET transistors (2SK170 ) . But I like the germanium preamps better ....These were experiments , and they are still ongoing - I am building another preamp . And this will be another germanium scheme .But there is still a lot of work to be done .

 

[vsmusic]

Soundhappy - Thank you for a good review of my work !

 

[Soundhappy]

Preamps on germanium transistors provide a very good sound-three-dimensional,
with a beautiful transmission of voice and acoustic instruments . I like these preamps.

@ Vsmusic

Thanks for sharing Your wonderful interesting DIY work. Very kind.

Yes me too i like it , after limited audio experiences they surprise me by his own amazing sound character.
Germaniums a semiconductors from " another planet " Scanned and cleaned up Wireless World Articles
https://www.keith-snook.info/wirele...rld-1961/Transistor Audio Power Amplifier.pdf
https://www.keith-snook.info/wirele...5/Transistor High Quality Audio Amplifier.pdf

 

[poynton]

Showing my age!!

I remember these when they came out.
Just when I first became interested in electronics.

Andy