question about germanium transistor

[slim_blues_boy]

hi, this is  my first post  .

A month ago, I decided to make some stuff using germanium transistor, and that would be Rangemaster, Tone Bender, and Fuzz Face.
so I started looking for germanium transistor on some local store.
and I these what I found so far:

Type      |hFE   |Leak(uV)    
-------------------------------   
OC75   |120   |230            
AC128   |-   |very high         
2SB22   |33   |110            
2SB22   |33   |50            
2SB22   |7   |20            
2SB22   |21   |50            
2SB22   |36   |100            
2SB22   |32   |60            
2SB22   |-   |very high         
2SB22   |-   |very high         
2SB22   |-   |very high         
2SB22   |-   |very high         
2SB22   |-   |very high         
2SB22   |7   |50            
2SB22   |25.5   |750            
2SB22   |147   |170            
2SB22   |237   |500            
2SB22   |95   |230                  
2SB54   |221   |270            
2SB54   |140   |150            
2SB54   |-   |very high         
2SB172   |91   |170
2SB175   |60   |110
2SB175   |72   |170
2SB175   |53   |100
2SB175   |72   |130
2SB175   |64   |100
AC125   |92   |170
AC125   |215   |260
AC125   |-   |very high
AC125   |-   |broke transistor
AC125   |-   |broke transistor
AC127   |-   |very high
AC127   |-   |very high
AC127   |13   |180
AC127   |16   |180
AC127   |-   |broke transistor
2SB178   |122   |560
2SB178   |60   |150
AC188   |-   |very high
AC188   |24   |110

as you all can see I'm a little bit unlucky when choosing germanium transistor.
from total 41 transistor, I only got 7 transistor with 'good' hFE (70-140).

my question, is there anything I can do with the rest of transistors?
what can I do with low hFE (between 7-64) transistor, is there any other project that suited with those transistors?
and what can I do with high hFE (between 215-221) transistor?

thanks for all helps  .

[rnfr]

the hi ones are great for boosters. 


you can use the others too if you bias right.

[slim_blues_boy]

the hi ones are great for boosters. 


you can use the others too if you bias right.

ok, so I still can use transistor with hFE 20 or 30 in Rangemaster, Tone Bender or Fuzz Face?

[Dai H.]

hi, check out the calculator for fuzz faces:

http://www.diystompboxes.com/analogalchemy/emh/emh.html

(if memory serves there was another one by someone else but memory is a bit foggy on who--marcelo from argentina??)

[rnfr]

the hi ones are great for boosters. 


you can use the others too if you bias right.

ok, so I still can use transistor with hFE 20 or 30 in Rangemaster, Tone Bender or Fuzz Face?

you can, if you bias it correctly.  although you might not get the amount of gain that you normally might think of getting in this type of design.  20-30 might be a bit low for that.  i do know that there are manufacturers pedals that have recently been measured using a trans with as low as 50 Hfe in Q1 of a fuzzface design. 

[smallbearelec]

I wouldn't say that you are "unlucky." You got some devices in the "gold" range for Fuzz Faces, and I see a few others that would work with correct biasing. The three in the 90s will be good for Q1, and the ones in the 200s with reasonable leakage will work for Q2. The devices in the 50s and 60s can be made to work for Rangemasters, or use them as Q1 of the TB Pro MKII. Very low gain devices? Check out my Bear Boost Plus.

http://www.smallbearelec.com/Projects/BearBoostPlus/BearBoostPlus.htm

Your yield doesn't look so bad now, right?

Regards
SD

[frank_p]

(if memory serves there was another one by someone else but memory is a bit foggy on who--marcelo from argentina??)

Exactly.

http://www.diystompboxes.com/smfforum/index.php?topic=52716.0
http://www.diystompboxes.com/smfforum/index.php?topic=47040.0

[petemoore]

  It's nice to see the 2SB's doing well in your tests, I like my Q1 which is a 2SB type.

[frank_p]

  It's nice to see the 2SB's doing well in your tests, I like my Q1 which is a 2SB type.

Why are you saying that Peter ?  I don't understand the sense of the phrase...  Should 2SBs have some issues or are they overlooked ?  Or is it because they are Japanese ?  They are also good for Q2...
I like mines...  I ask these question because I have more Japanese transistors than European or American ones, and the ones I have do not tend to leak a lot.

[slim_blues_boy]

I wouldn't say that you are "unlucky." You got some devices in the "gold" range for Fuzz Faces, and I see a few others that would work with correct biasing. The three in the 90s will be good for Q1, and the ones in the 200s with reasonable leakage will work for Q2. The devices in the 50s and 60s can be made to work for Rangemasters, or use them as Q1 of the TB Pro MKII. Very low gain devices? Check out my Bear Boost Plus.

http://www.smallbearelec.com/Projects/BearBoostPlus/BearBoostPlus.htm

Your yield doesn't look so bad now, right?

Regards
SD

that's interesting project to do.
I hope I can find all the components, I don't know whether all parts are available in my country.
if I can't find some of them, maybe I will buy them from you place .
I already have plant to buy components from your place, but I'm still waiting for the money coz I want to buy some components at one time to save some from shipping fee.
shipping fee is big issue for me coz it will cost me a lot  .

thanks for your info  .

[slim_blues_boy]

(if memory serves there was another one by someone else but memory is a bit foggy on who--marcelo from argentina??)

Exactly.

http://www.diystompboxes.com/smfforum/index.php?topic=52716.0
http://www.diystompboxes.com/smfforum/index.php?topic=47040.0

too bad that I can't download the calculators.

but thanks anyway .

[slim_blues_boy]

  It's nice to see the 2SB's doing well in your tests, I like my Q1 which is a 2SB type.

  It's nice to see the 2SB's doing well in your tests, I like my Q1 which is a 2SB type.

Why are you saying that Peter ?  I don't understand the sense of the phrase...  Should 2SBs have some issues or are they overlooked ?  Or is it because they are Japanese ?  They are also good for Q2...
I like mines...  I ask these question because I have more Japanese transistors than European or American ones, and the ones I have do not tend to leak a lot.

in my place, I only can find European and Japanese transistor.
I can't find the American one.
even the European are very-very rare.
Japanese transistor is the common one here.

[slim_blues_boy]

I have another question  .

I think somehow I'm obsessed with germanium transistor.
so I think will buy another germanium transistors when I have the money.

there are 2 stores that sell germanium transistor in my city.

the first store still have AC125, AC127, AC187, 2SB173 and other type transistors, European and Japanese type.
the price is cheap, only 0.2 US$ for one transistor, all type.

the other store have 2SB172, 2SB175, 2SB178 and other Japanese germanium transistors.
but the price are a little bit expensive, between 0.6 - 1 US$.

I have read some transistor that would be suited in Fuzz Face on Small Bear website.

Code Select Expand

http://www.smallbearelec.com/HowTos/FuzzFaceFAQ/FFFAQ.htm

so my question is, can I work with other type of germanium transistor beside transistors that mentioned on Small Bear?

[frank_p]

Absolutely,
read in the data books and and spot the ones where the gain will "match" what you are searching for.  The gains will probably vary compared to the datasheets but you'll have less chance of having trannies with gains that you don't want.

A good place to look for data:
http://www.classiccmp.org/rtellason/   

[darron]

is there any other project that suited with those transistors?

and you can always use a crappy one for this:
http://www.muzique.com/news/leaky-transistor-buffer/
http://www.muzique.com/news/leaky-ac128-buffer-redux/ (positive ground version)

[Solidhex]

Yo

  There are some circuits that thrive on a decent amount of leakage. Say 400-500ua. Like the early Tonebender and Maestro fuzz.

--Brad

[slim_blues_boy]

Absolutely,
read in the data books and and spot the ones where the gain will "match" what you are searching for.  The gains will probably vary compared to the datasheets but you'll have less chance of having trannies with gains that you don't want.

A good place to look for data:
http://www.classiccmp.org/rtellason/   

ok, thanks for the info.
I will hunt for germanium transistors soon  .

[slim_blues_boy]

is there any other project that suited with those transistors?

and you can always use a crappy one for this:
http://www.muzique.com/news/leaky-transistor-buffer/
http://www.muzique.com/news/leaky-ac128-buffer-redux/ (positive ground version)

ah, thanks for the info.
I almost throw those leaky transistors to my garbage.
I always try to use all components that I have, and now I can use those leaky transistors as a buffers.

[slim_blues_boy]

Yo

  There are some circuits that thrive on a decent amount of leakage. Say 400-500ua. Like the early Tonebender and Maestro fuzz.

--Brad

ow really?
I think I will do some experiment with those transistors that have leakage 400-500uA.
thanks for the info.