Germanium investigations

[Soundhappy]

direct download: https://ia600804.us.archive.org/1/i...etry_audio_transistors_circ_20170807_0044.pdf
source:Complementary symmetry audio transistors circuits and data, from Amperex: : Free Download, Borrow, and Streaming : Internet Archive
Thanks to Archive.org 🙂

 

[Soundhappy]

Phono 2N185 preamplifier https://ia801903.us.archive.org/6/i...Transistorized_Hi-Fi_Preamplifier_Aug1959.pdf
You can try find some equivalents of the original https://ia801904.us.archive.org/14/items/bitsavers_tidiscrete_1123234/2N185.pdf
Edit: Power Ge + https://ia803201.us.archive.org/10/...5132N514_13950654/2N511_2N512_2N513_2N514.pdf

 

[indra1]

Special for Germanium soldering ...

These days we also have Temperature controlled soldering iron and Low temperature bismuth solder.

 

[poynton]

Phono 2N185 preamplifier https://ia801903.us.archive.org/6/i...Transistorized_Hi-Fi_Preamplifier_Aug1959.pdf

I built many preamps using circuits just like this !!!

The third stage could be added to increase the gain or to add a microphone section.

Andy

 

[Soundhappy]

These days we also have Temperature controlled soldering iron and Low temperature bismuth solder.

Thanks for the suggestion,
but low temperature bismuth solder is not my cup of tea, go for it if you like it.

My soldering station temperature is adjusted to the solder melting point, made hot and very quick soldering.
Use crocodile clip on the transistor lead to not overheat germanium chip is easy to implement solution for me.

Your choice is different and can be similarly good 🙂 Have a nice day

 

[Zoran]

Hi 🙂
just to add nice Germaium RIAA circuit:
Germanium DIN Entzerrer auf RIAA trimmen, Analogtechnik/Plattenspieler - HIFI-FORUM
looks very interesting to me

 

[analog_sa]

Hi 🙂
just to add nice Germaium RIAA circuit:

It's certainly interesting but i have no idea what is "iec nr. 98". Are these standard time constants?

 

[poynton]

.
.
.4 transistors as opposed to 2 in the TI circuit

.More noise unless you choose them carefully

.

 

[Zoran]

It's certainly interesting but i have no idea what is "iec nr. 98". Are these standard time constants?

Probably some of numerous LP eq-s? But I think that is not the big deal to exchange time constants within the pasive components to acheive stnadard riaa eq?
(I think that I am remember that I was checking circuit with spice and with silicium devices and EQ can be adjusted to riaa slope?)

 

[OldDIY]

RCA Victor & IEC No.98
refers to this "New Orthophonic" standard since 1952.
Recommendation of 1953 by NARTB, of 1955 by IEC No.98, and B.S. No. 128. World standard since 1964.
Time Constants: 3180 µs (50 Hz), 318 µs (500 Hz), and 75 µs (2,120 Hz).

TELDEC
Telefunken and Decca founded a record company that used a characteristic proposed for German DIN-Standard on July 1957: DIN45533, DIN45536, DIN45537.
Time Constants: 3180 µs (50 Hz), 318 µs (500 Hz), and 50 µs (3,180 Hz).

#366 Will work great on SI BJT.

 

[vsmusic]

Broadcast phono preamp GATES M-6169 .

 

[vsmusic]

Phono preamp SABA Telewatt

 

[vsmusic]

Preamp General Electric & chinese clone ...

 

[astouffer]

The Amperex book is amusing. They boast about operating in class B instead of wasteful class A.

 

[Soundhappy]

@ Astouffer

Yes but for consummer audio products, too lazy make heatsinks metal work..
This old Amperex book example makes build modern class A Ge amplifiers more interesting challenge.
Something to discovering or re-discovering in XXI Century

 

[Soundhappy]

Remember the time in the 60´s
word "transistor" means in popular language class B small size pocket radio more than semiconductor component.. 🙂

 

[drjbf1]

On my shelf is this old secondhand book published in 1969. I thought it may be of interest.

Keep up the good work Soundhappy

 

[poynton]

.
.
Some of the older books still have good ideas.


.

 

[Charm]

Translate the famous John Linsley-Hood's scheme to Germanium, at the output of GT806 and 1T813, changing the polarity in the scheme, a little finalizing you can get a wonderful sound. With amazing meander in 200 kHz.

 

[Soundhappy]

On my shelf is this old secondhand book published in 1969. I thought it may be of interest.

Thanks for sharing and kind words Have a good time

..Some of the older books still have good ideas.

This sophisticated one + 1K pages included on the list. Public domain from Archive.org
Amplification with tubes and transistors, bunch of circuits examples and lots of deep knowledge..Highly recommended!
direct download : https://ia801904.us.archive.org/32/...s and Low-Pass Amplifier Design (1968)-RR.pdf
source:
Cherry, Hooper Amplifying Devices And Low Pass Amplifier Design ( 1968) RR : Free Download, Borrow, and Streaming : Internet Archive
Probably Papa book he was young student at University ?