Fisher 1210X

[waltr]

Thank you very much, here I was digging through old box looking for 2.5 volt zener, guess what, I have a million zener diodes, but not a single one around 2.5volts! Its probably the only one I DON'T have! What rotten luck. Now I can use your circuit as substitute, thanks again.

Which is another reason why the Shut regulator was used.

This 2.5V is a 'Virtual ground' for the Op-amps so there are many ways to produce this. Also, there are many part numbers for shunt regulators.
I use ZR431 or LT1009.
Here are ones that Mouser has in through hole, many more in SM (maybe one of these is available locally).
https://www.mouser.com/Semiconductor...ulator&FS=True

Here are Voltage References:
https://www.mouser.com/Semiconductor...z0wa2kZ1z0z63x

Or build the circuit posted above.
Or use a resistor divider into an Op-amp Follower.

[dbanner]

Yes, I see, Hmmm, seems like many options available for power supply. It is not problem for me. Was trying to avoid building a little piggy back circuit just for power supply. But no problem, I can use rimatron PS circuit.