About Transistors in Sansui Schematic

[Kale]

I have one question about labeling transistor in Sansui schematic diagrams, what means these letters in parentheses beside the name of transistor?

Regards!

 

[EchoWars]

Usually refers to the gain class or hfe grouping. Different letters for different groupings.

For instance, the data sheet for the C2238 says a group 'O' device sould have a gain of between 70 and 140, and a 'Y' device bewteen 120 and 240.

 

[kcollins4]

Also, be careful not to mix the (O,Y) transistors with the (V,E,Y) The result will be the rare, oy vey Yiddish transistor. Sorry...couldn't lay off that one

 

[BrandXRC]

Good one, KC

 

[nosirrah]

Kc

ahhh you tinkin they speaka da yiddish in Croatia? You silly man...
C

 

[Kale]

Usually refers to the gain class or hfe grouping. Different letters for different groupings.

For instance, the data sheet for the C2238 says a group 'O' device sould have a gain of between 70 and 140, and a 'Y' device bewteen 120 and 240.

Thank you EW, but I have another question; why is STV3H bias diode marked as (Y,G), or in some another case 2SC1775 is marked as (E,D) and 2SD357 (D,E) why, is it the same?

Also, be careful not to mix the (O,Y) transistors with the (V,E,Y) The result will be the rare, oy vey Yiddish transistor. Sorry...couldn't lay off that one

I don’t understand what you trying to say; I see that something is funny, but I don’t understand what


Regards!

 

[kcollins4]

Sorry Kale, I didn't mean to confuse you. It was a not very good joke.

 

[EchoWars]

Thank you EW, but I have another question; why is STV3H bias diode marked as (Y,G), or in some another case 2SC1775 is marked as (E,D) and 2SD357 (D,E) why, is it the same?

Each transistor manufacturer decides what gain grouping their transistors will have, and assigns an arbitrary letter to the different grouping. I don't know how that is decided, and it really isn't important.

The bias diodes are assigned letters not for gain, but for the forward voltage drop, and the rate at which that drop changes according to temperature. Again, I don't know the criteria used to decide what letter is used. If the original manufacturer's data sheet could be obtained it might help explain what the letters mean, but it won't tell you why they used a 'G' instead of an 'O', and it isn't worth losing sleep over.

 

[Karl vd Berg]

Gain Class of Transistors - P, Q, R, S, Y, O, etc.....

I have one question about labeling transistor in Sansui schematic diagrams, what means these letters in parentheses beside the name of transistor?

Regards!

Actually this subject - gain class of transistors - tends to become still important as people will lately look for the proper part in order to replace the originals.

This is a thread from 2006. For many it's still a tough task in finding replacements or "good equivalents" for an old amp, for instance. Some manufacturers don't make anymore that 2SCxxxx type anymore. Putting a "modern equivalent" in some cases would perhaps require to modify other parts in the circuit?

 

[markn2wae]

Are they LOCATION coordinates?

Is it possible these are LOCATION (X,Y) coordinates from the schematic to a parts diagram of the PCB? :scratch2:

The pictorial of the PCB would have numbers\letters along the edges so you could find the part on the board and relate it to the schematic, sort of looking up the location of street names on a map.

Mark T.

 

[Kico]

Also, be careful not to mix the (O,Y) transistors with the (V,E,Y) The result will be the rare, oy vey Yiddish transistor. Sorry...couldn't lay off that one

ROFL and LAMO...we certainly have some creative thinkers here

 

[clinic-audio]

hello !

No , the letters are sometime for Hfe classification and some Japanese manufacturer use color abreviation
For example : 2SA970 (V,Y) mean Yellow and violin acceptable
2SC2240 (GR) mean green only
etc ...
Everything is normally ON the semi-conductor and IN the data-sheet !

:thmbsp:

 

[Hyperion]

Thanks clinic-audio - nice to have your expertise in the Exclusively Sansui forum. :thmbsp:

Your explanation is what I thought it was too - but was not sure.

 

[ghazzer]

Karl: Thanks for reviving this thread. Some of my recent efforts to find suitable subs for old transistors have been stymied when I am unable to find original data sheets to decipher the class codes. They must not be consecutive because I have seen too many like "(E,Y)".

www.alltransistors.com has an extensive data base. I can even find a data sheet for a 2SA1106, but it does not list any of the gain classes that are shown on the Sansui schematics. In situations like this I tend to go with a mid to higher gain because I have assumed that using a lower gain will adversely affect the performance.

Are there any guidelines for this????

 

[Karl vd Berg]

Karl: Thanks for reviving this thread. Some of my recent efforts to find suitable subs for old transistors have been stymied when I am unable to find original data sheets to decipher the class codes. They must not be consecutive because I have seen too many like "(E,Y)"

That's the idea, Steve. :thmbsp: