Voltage clamp using transistor?

[Electric-Gecko]

Hello;  I am designing a new pedal (which I should post when finished).
For part of the pedal, I need to have a voltage slightly lower than the reference voltage (by roughly 1V).  So I designed this:
]
But I would like to know how to achieve this with transistors; just to save parts and space.  But I can't figure it out.  Please note that where it says "Shunt" it is only shunting higher voltages.
There must be a way to do this with either a MOSFET or a BJT.  But I figure that a FET would be preferable as it would draw less current from Vref.

[anotherjim]

NPN transistor. +V to collector, Vref to base, output from emitter will be base-emitter junction drop (Vbe) below Vref. Is that what you want?
Essentially this circuit but Vref replaces the zener and bias resistor...

[Gus]

If I understand your post
Make the Vref part with three resistors. Make R2 two resistors that add up to R1 with the node between the two R2 resistors being at Vref -1VDC. Remove R3 and D1
use ohms law to work this out
Is Vcc 9VDC?

[Rob Strand]

There's not enough information to optimize the circuit:
- Does the "shunt" terminal need to source current, sink current, or both?
- How accurate does the 0.8V need to be?

(Same as anotherjims)
For a source (current out of the shunt terminal):
- 1x NPN transistor:  collector to +V, base to Vref, emitter = output
- the output will be 0.6V to 0.7V below Vref

For a sink (current out of the shunt terminal):
- Take the 33k+diode you have but add an extra diode
- 1xPNP transistor: collector to GND, base to the 33k+diode junction,emitter = output
- the output will be Vref - 2*Vdiode + Vbe
You might need to change the 33k to suit the current draw.

For both source and sink you are better off with an opamp.  However you can connect a dummy load to ground in the first case and +V in the second case to get a small degree of current in the other direction.

You say it the shunt terminal is to shunt high voltages.   What are you doing exactly?

[PRR]

[antonis]

Or just add a series Si + Schotky diodes to your existing Vref..
(more soldering joints than Gus proposal..)

Is there any need for current passing transistor..??