Pioneer SA7800 stv2h diode

[PTSOUNDLAB]

Hello,
I search 2 Sanken STV2H for an old Pioneer SA7800. Does somebody know where I can find these spare parts or know a good substitute.
I despair to find.
Thank you
Best Regards
Pascal

[PTSOUNDLAB]

the schematic

[destroyer X]

This is only to produce a voltage reference.... also you have adjustments...so....not needed to use the same.... so... if the new diode reference voltage (the voltage that will appear when measuring into the leads) results sligtly different... the trimpots are there to compensate.

Other diode will work.... same work... it is alike Coke inside the bottle and Coke inside the glass...both are Coke....tastes Coke, smells Coke...because it is Coke!

Se parrait...parce que c'est le même chose.

C'a marche!... allons enfants de la eletronique!

Carlos

[anatech]

Hi Pascal,
Did you break yours? If not, the bias control (VR5) is probably bad as well.

That part was discontinued many years ago. Look for those in scrap amps and receivers from the same time era as yours.

Now, for a new solution you would put together a VBE multiplier. This part is used as a temperature sensor to compensate the bias current. Using a pair of diodes is risky as they need to be mounted on the heat sink directly. The transistor in a VBE multiplier can mount in the same place with a small PCB.

A "VBE multiplier" is simply the standard type of bias control circuit that has been used in newer equipment. Look at some newer schematics and you'll see what I'm talking about.

-Chris

[destroyer X]

......so..... as a consequence, my single diodes substitution may not be a good idea.... to use my idea the diodes may need some kind of insulation (schrink tubing) and to be glued into the heatsink.

Thank you Anatech.

regards,

Carlos