I am in the process of restoring my Sansui 9090 driver board (F-2436 late production). This may be a dumb question but here it is. TR07 and TR08 are I believe bias transistors. They are both 2SC984 s but one has a ‘B’ inside a circle and the other has a ‘C’. I have the ones with ‘C’. My question is do I need a ‘B’ for TR08? I seem to remember reading that the C means the collector is attached to the can and I suppose B would be attached on the ‘B’ can and if they aren’t correct can wreak havoc on the circuit. Is this true? TIA
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Welcome to the forum.
The B & C labels indicate the beta (Hfe) groups.
It may or may not be important for this particular application but a schematic is needed.
I included the transistor datasheet. You will find A, B, C and D groups.
Hugo
The B & C labels indicate the beta (Hfe) groups.
It may or may not be important for this particular application but a schematic is needed.
I included the transistor datasheet. You will find A, B, C and D groups.
Hugo
First thing: why would you change these transistors? Are they broken?
Second: They both do the same job, one in the left, the other in the right channel.
They've probably been there for ages so it doen't matter if you would exchange them for the C-types. Both types seem to have worked well.
Also, the schematic indicates that both B & C types can be used.
Hugo
Second: They both do the same job, one in the left, the other in the right channel.
They've probably been there for ages so it doen't matter if you would exchange them for the C-types. Both types seem to have worked well.
Also, the schematic indicates that both B & C types can be used.
Hugo
TR08 is the Vbe multiplier. Since they specified either B or C , B would at least give a slightly negative global tempco.
C with its higher gain , would be a little more aggressive in the negative direction. Either would be safe.
BTW , that is quite the reliable little amp circuit. Similar to the forum's "Badger".
Bet they use little disk ceramics for C5-6 ,17-18 - an upgrade would be 1% 3-500V silver mica's.
And , C7-8 - 25-35V NP "MUSE". It lives forever.
OS
C with its higher gain , would be a little more aggressive in the negative direction. Either would be safe.
BTW , that is quite the reliable little amp circuit. Similar to the forum's "Badger".
Bet they use little disk ceramics for C5-6 ,17-18 - an upgrade would be 1% 3-500V silver mica's.
And , C7-8 - 25-35V NP "MUSE". It lives forever.
OS