Replace Sanken SAP16 with STD03

[yano]

Hello everybody, I'm a new user from Italy.

I'm trying to repair a SAP-16 equipped amplifier. I know SAP series darlingtons are discontinued, and I can replace both of them (sap16p & sap16n) with a couple of STD03.

I learned from this forum that STD03 doesn't have the emitter resistor onboard... so, I downloaded the datasheets, but I really can't figure out how to connect the emitter resistor. I know, it's a very basic operation, but I'm a little confused 😕...

Does anybody of you ever done this before?

Thanks in advance!

 

[jan.didden]

Yes I did. What you need to do is connect an external emitter resistor between the emitter and the amp output. Use 0.22ohms 3W or so.

Jan

 

[yano]

Great! Now It's clear... I was confused by equivalent schematics on the datasheets.

Thanks a lot!

 

[jan.didden]

BTW Do you know why they went from the SAP to the STD types? The internal R would blow before the transistor would blow, making it pretty useless 😀

Jan

 

[yano]

Yeah, I read about that 😀 (maybe in this forum...).
Pretty embarassing for Sanken 😱

 

[snootypoo]

Yes I did. What you need to do is connect an external emitter resistor between the emitter and the amp output. Use 0.22ohms 3W or so.

Jan

Hi, Im getting confused as well, more about the sence pin. Im replacing SAP16n with STD03N in an old amplifier.

I gather the circuit still wants to see the sence pin, SO:
Should I:
Solder the emitter leg of the STD03N into where the sense pin used to go on the circuit and the tap off the emitter leg and run the 0.22 resistor to the original emitter hole on the circuit?

THanks