Developing a Regulated Dual Rail Power Supply For FirstWatt Amps

Developing a Regulated Dual Rail Power Supply For Pass DIY Amps

Why did I choose bipolar transistors?

1) Smaller voltage drop across transistors compared with mosfets, which means less heat generated/wasted
2) A larger variety of suitably matching npn and pnp devices
3) I have a stack of bipolar transistors in my stash of parts that will probably never be used in an amp circuit.

I have not had the chance to test this circuit in the lab as yet, and would appreciate advice on improvements that aren't radical changes to the original circuit.

Here is the positive half of the circuit

Sorry about photobucket no longer showing images.
I will update here later with full documentation eg pdf or similar

Last edited:
Given that most people are usually satisfied by a CRC supply I'm starting to think that the highest priority here is ripple reduction, followed by decent output impedance, with regulation being at the bottom of the priority list. So I'll also do a straight Capacitance multiplier supply as well, which has the advantage of an even smaller voltage drop.

Just thinking out loud.

I'll post up all the potential circuits
Joined 2002
Paid Member
What about a cap multiplier with a mosfet but adding a battery in the 3 to 6v range in series with the gate . This way you could have the voltage on the gate about 3 volts higher than the drain voltage so you wouldn't lose but a volt or so in the mosfet.
you need bloody reservoir cap on output

build it , then listen with and without

then choose

I have held off from doing that because you get a rising impedance response with decreasing frequency ie higher impedance in bass region as opposed to flat impedance.

If I add a reservoir cap it's gonna be 200,000uF to reduce this effect. Do you think there will be any problem with such a large capacitor on output?
I'm quite happy adding more bipolar transinstors if require.

Burning Capacitance Multiplier 1