The Cathode Follower triode and the 10k load resistor also define a voltage divider; therefore, if the AC resistance of the sum of the tube's rp and cathode resistor equals 10k, the voltage division will be one

half. The math is simple enough: AC resistance  =  rp + (µ + 1)Rk, e.g. 3,200 + (33 + 1)200 = 10,000. Once again, one half of  AC +1 and -1 is 0. Thus the use of a split rail power supply results in an even greater PSRR figure than the already good figure the Cathode Follower normally exhibits.

What about the phase splitter half of the circuit? Here is where the Split-Load Phase Splitter comes in to play. This phase splitter has a great PSRR figure relative to its cathode and a very poor to non-existent one at its plate. This discrepancy can be used to our advantage. Because we are using a split rail power supply, the phase splitter's cathode resistor will see virtually no noise at the cathode connection and all of the noise of the

negative power supply rail at the other end. This AC voltage will define an AC current through this resistor and the triode and its plate resistor. This means that the pulsing noise voltage across the cathode resistor will define a pulsing voltage across the plate resistor. We have already stated that the PSRR at the plate is nil, which means that what noise exists at the positive rail, will also appear at the plate of the triode. So if the rails pulse a total of 2 volts away from each other, the plate resistor will move up 1 volt and develop 1 volt across its resistance, which will cancel the 1 volt upward movement and result in 0 volts movement at the triode's plate. Magic? Not really, just good engineering.

Why a 6922?
The tube chosen was a 6DJ8 type dual triode, as it boasts both a relatively high gain and high transconductance and it works well with only 66 volts across it. If the rail voltages are increased, other tubes could have been used in building this line stage. For 9 pin fans, the choices are many: 6AQ8, 6FQ7, 12AU7, 12AT7, 12BH7, 5687, 5963, 5965, 7119, and don't forget the dissimilar mu triodes, such as the 6CY7, 6DR7, and 7247. For octal fans, the best choices are the 6SN7, 6EM7, and 6DN7. 

Which sort of power supply should be used?
Because this circuit has been optimized for PSRR, the power supply does not need to be regulated. The split rail supply is easy to realize, as center-tapped transformers are readily available. One such transformer is made by Hammond and is available from Antique Electronics: P-T263AX. It comes with three secondary windings: 100-0-100 VAC @100 mA, 5 VAC @ 2 A, and 6.3 VAC @ 2 A. If the 200 CT secondary is hooked up to a silicon bridge rectifier, it will put out about +/- 140 VDC. This voltage can be dropped down to =/- 100 volts by including a 5 watt, 1,275 ohm resistor in each rail.