TEWA Germanium Transistors from Poland are great !!!

[M23Bomber]

Hello All,

TEWA Germanium Transistors from Poland are great !!!

ASY34, ASY35 and ASY36 are PNP Germanium transistors made by an extinct polish company called TEWA, I bought a pair of each of them from an old worker that I met in the Wolumen street market. They are equivalent to AC128, but with better voltage ratting in the datasheet.

http://www.mif.pg.gda.pl/homepages/jasiu/oldtr/ASY34.html
(Use google Translate )

I made a simple test by building a booster, without making any bench testing, and they seem to be consistent to my ears.

I was impressed with the quality.   Who knew that Poland still had these little surprises.

Regards,
M.

[M23Bomber]

 k

[tjdracz]

They are not the most popular ones unfortunately and quite expensive to the point when you can get better ones for half the price.
The most popular TEWA ones were TGx series, mainly TG3 i think but they had miserable gains.
I'm from Poland and I got some of them going to find a untapped germanium gold mine but was sorely disappointed.
My dad was an electronic engineer and couple of years back, threw away loads of old junk electronics, all full of germanium transistors. Little did he know how obscenely valuable they would become. Back then it was just junk and everyone thought that silicon was just better. I guess from non-mojo chasing pedal builder perspective it was as simple as that.
Hell, they even had some of the ac128 and Mullard oc44 in these first transistor radios!
Went to the electronics market around December and found some of those TEWA's in electronic junk boxes. Still, they wanted around £1-1.50 a piece. Gave it a miss then

[tjdracz]

Actually, I've just looked and found ASY34 for about £4 for 10 NOS with shipping in Poland. Only see two packs of them advertised, but the seller might have some more. I can haul some over to the UK and distribute them further if anyone was interested. If you are, give me a shout.
Mind you, they are HF ones. Thought we liked our germaniums for their low Ft and inability to serve those harsh high frequencies, right?

[M23Bomber]

Witam!

These ASY34 an 35 in the data sheet seem to be fast switchers, only a bit more that the AC128, but compared to silicon PNP, the ASY having to 2 to 4 MHZ  Ft is much less than 150MHZ of a silicon . And they sound good. Setting a low pass filter in the input is enough to solve it 

Regards,
M.

[Mario44]

The most popular TEWA ones were TGx series, mainly TG3 i think but they had miserable gains.

I've tried to build a simple treble booster with TG3 but it was very weak and the "boosted" signal was below bypassed signal

pozdro

[tjdracz]

The most popular TEWA ones were TGx series, mainly TG3 i think but they had miserable gains.

I've tried to build a simple treble booster with TG3 but it was very weak and the "boosted" signal was below bypassed signal

pozdro

Exactly my point!

Pozdrawiam

[M23Bomber]

Witam, 

Post the original schematic here and I bread board. record the result and put it here.

Pozdro
M.

[M23Bomber]

TG3 has arround 4k of CE resistance   while the ASY34 has much less, arround 200ohm, this will affect the gain, just recalculate the base bias and it will amplify better. But did you test the leakage current and hfe of the transistors that you used for the project? And more important where did you put the ground of the leads from the jacks in 9v or the 0v?

M.

[Mario44]

I guess this is the schematic i used

Well, I didn't look to datasheets. Just had few trannies so I put them into board without chaning anything else.
Maybe thats the point and chaning base bias resistor would fix the gain problem

[M23Bomber]

Hello Mario,

Try it like this for the TG3.



or

http://postimg.org/image/6ro4qcirh/

BR
M.

[M23Bomber]

Hello All,

After getting a few  a few more ASY35, I tested them, while monitoring their temperature

Out of 10 NOS ASY35:
Highest HFE: 206(?)
Lowest HFE: 51
Highest Current Leakage : 505 uA
Lowest Current Leakage : 157 uA

Regards,
M.

[darron]

i know of some ge transistors that are really amazing. but i don't tell people about them so there's more for me

[Digital Larry]

If you are going to bias your transistors to make them behave linearly, what possible benefit do you hope to get from Germanium?

"My theory" (it's just that) is that Ge is ideal for use in grounded emitter designs (i.e. fuzz) because the output voltage of most guitars is just better suited for the lower turn on voltage, and the medium gain gives an appealing range of sounds that can be adjusted via volume knob. 

But if you want it to just be a booster, why not use silicon?  Reduced frequency response is easily accomplished using cheap capacitors.

I haven't built any boosters one way or the other so I'm probably missing some obvious point.

[M23Bomber]

Hello Darron

I understand your point of view if you are someone building pedals with the intent to sell them. Secrets are the soul of any business. Polish Germanium PNP Transistors also  

But since Im only an enthusiast and I believe that sharing this type of information is useful for a few reasons:

- Good things need to be recognized and people should know about them. If only one person knows, then it only has value for a single element of our community, and other people will not have confidence in them due to the lack of this information. Such as in this case with the PNP Germanium transistors.

-Here in Poland, there was a for many years a semi-conductor industry,brands like Tewa or Unitra, when the USSR in 89  disintegrated,  the new polish government sold lots of assets, also stock from many companies, to get quick cashflow, also there was some "stock redirecting" by some workers Some of the items were traded right after, but an almost equal amount was simply left in an attic or storage rooms in the buildings ,and, forgotten. These forgotten items,(Alsp PNP Germanium Transistors) quite often can be found in the electronic street markets, such as Wolumen in Warsaw, or polish auction websites.

- It is quite unpredictable when ordering any kind of transistors online, thats why Im sharing my finding, so that Polish Audio DIYers are aware of what they have at home, and how cool would it be to build fully polish Effect pedal, only vintage polish parts. The challenge is launched to my self and others

I hope this is a good explanation of my point of view.

Regards,
M.

[tjdracz]

Some of the items were traded right after, but an almost equal amount was simply left in an attic or storage rooms in the buildings ,and, forgotten. These forgotten items,(Alsp PNP Germanium Transistors) quite often can be found in the electronic street markets, such as Wolumen in Warsaw, or polish auction websites.

Do they still sell those at Wolumen? Going back to Poland quite.soon and wanted to go to electronic markets to find some stuff but wanted to know first whether they are still there and if it's worth checking out

[M23Bomber]

As you might know the best day to find any electronic component is Sunday, when all the once a week salesman appear, you know all "table storess",not really in shops, like RCS or Soltronik. Just go on a Saturday or Sunday look around carefully and you will find it in one of the tables. Also there is Allegro and Tablica, there you will find them but you need to search for the specific transistor by its name, it wont pop up just by writing "Tranzystor Germanowy". Most of the time it doesnt anyway

M.

[M23Bomber]

Hello all 

Here is a fresh report about the PNP Germanium transistors from poland, this time its the very polish ASY 34.

ASY Germanium transistors features: They are easily affected by temperature changes, as any germanium transistor . In general they have very low leakage and a very constant gain under stable temperature and voltage, and they have low leakage and a good gain ( HFE). According to the fabrication serial number we can more or less have an educated guess about its features. this can be verified by the number or letter under the transistors name. After my testing with RGs germanium tester circuit at a stable temperature of 24 degrees celsius with a stable 9v power supply, and I reached some conclusions. I could have used different testing methods that would be much more precise, but I decided to use this one because it can be easily replicated by anyone , anywhere, and this will allow the sharing of results more equivalent.

Here goes:

ASY34S 6 and ASY34S 7- Low leakage current, the hightest I found was around 200uA. The Hfe was quite constant around 50 - 70.

ASY34S 9 - Very low leakeage current, between 20uA and 50uA but an Hfe from my own testing from 20 to 45.

I will test later the ASY35 3D and 5F.

Regards,
M.

[M23Bomber]

Hello All 

Here goes some info about the ASY35 3D and 5F. I got 10 units of each.

ASY35 3D - Average Hfe 70 to 90, leakage current averaged arround 150uA.

ASY35 5F - Average Hfe 90 to 130, leakage current averaged arround 100-200uA.

Soon I will prototype a tone bender with these guys. And post the info here.

M.