This PSU takes a single 15-18VAC input and gives dual 15VDC output.
It is dead simple, has excellent performance, and consists of the following stages:
- Single 15-18VAC input
- Two half-wave rectifiers
- Voltage doublers
- LM317/337 voltage regulators
- Filter capacitors
- +/- 15VDC and ground output.
By using a wallwart, there is no risk of electrocution or fires.
The PSU performs superbly. Used together with the Muffsy Phono Preamp PP-2, it has only 0.1 mV ripple on the DC output. Well below the Power Supply Rejection Rate (PSRR) of any operational amplifier, and very suitable for discrete circuits.
The PSU gives up to 100 mA of current when used without heatsinks. That's enough to power four phono stages.
Mount heatsinks on the LM317/337 components and replace the 10R/1W resistors with 4.7R/1W if you need more current than this.
If you need exactly the same positive and negative output power, match the 300R and 3k3 resistors. With no matching, you can expect a maximum deviation of ~10 mV.
These AC to AC wall transformer are suitable for use with this PSU: