Build the Muffsy PSU v2 | Muffsy Phono Kits

Build the Muffsy Hifi Dual Power Supply

Please note that the Muffsy Hifi Dual Power Supply is delivered as a printed circuit board only. You need to buy the components listed in the bill of materials below.

A 15-18 volts AC wall adapter is needed to make this power supply work. Here is some more information about what you need to build the Muffsy Phono Preamp and Power supply.

You can also have a look at the schematics for the Muffsy products under the Modify It page.

Illustrations Explained

The picture below is a larger version of your printed circuit board. For each step, this will be used to show you which components you will be adding to the board.

This picture shows you where you are in the build process. It also shows what each component looks like, and it will contain special instructions or information.

Bill of Materials

These are the components needed to build the power supply.

There are lots of options available, alternatives from Mouser and Farnell are given where applicable:

Quantity	Component	Mouser Alternatives	Farnell Alternatives
7	Diodes, 1N4004	583-1N4004-T	12T2303
2	Resistors, 0.25W Metal Film, 300 ohm	603-MFR-25FRF52-300R	38K5327
3	Resistors, 0.25W Metal Film, 3300 ohm	603-MFR-25FRF52-3K3	38K5334
2	Resistors, 1W, 4.7 ohm	660-SPR1CT52R4R7J	59T0018
5	Ceramic Capacitors, 100 nF	140-50V5-104Z-RC	97K4396
2	Electrolytic Capacitors, 25V or higher, 10 uF	647-UVR1H100MDD1TD	33K2335
1	Electrolytic Capacitor 35V or higher, 220 uF (Grid: 5.8 mm, Diameter: 10 mm)	647-UVR1H221MPD1TD	09J5056
4	Electrolytic Capacitors, 50V, 2200 uF (Grid: 7.5 mm, Diameter: 16 mm)	647-UVK1H222MHD	55K2543
1	Voltage Regulator, LM317T	511-LM317T	58K8936
1	Voltage Regulator, LM337T	512-LM337T	58K8937
1	Wall Adapter, 15-18V AC	Suitable wall adapters	Suitable wall adapters
1	Male Power Jack, 2.1 mm	According to project requirements *)	According to project requirements *)
1	Screw Terminal, DG301, 2 Positions (Grid: 5 mm)	710-691102710002	04R6852
1	Screw Terminal, DG301, 3 Positions (Grid: 5 mm)	710-691102710003	04R6853

*) It's hard to give a good suggestion of a power jack, as this will depend on your requirements. Please note that a power jack is included with the Muffsy Back Panel.

Before you move on, you might want to have a look at how to modify the Muffsy Hifi Dual Power Supply and its AUX Power, so you can get the component values you need.

Step 1: Solder the Diodes

There are seven 1N4004 diodes on the board. They have to be oriented correctly. The silver band on each diode matches the symbol on the printed circuit board.

Step 2: Solder the 0.25W Resistors

There are five of the 0.25W resistors, they can be oriented whichever way you want. It is a good idea to measure them before they are soldered in place.

If you need the exact same positive and negative output voltage, you should match the four resistors on the right side of the board. If you don't, the voltages will only differ by 20-30 mV maximum.

Step 3: Solder 1W Resistors and Ceramic Capacitors

The two 1W resistors and the five ceramic capacitors can be mounted either way. I like to mount the capacitors so the text can be seen.

Step 4: Solder 10 uF Electrolytic Capacitors

There are two of these small electrolytic capacitors. Make sure that the white band (negative) is pointing upwards when the board is oriented as on the pictures.

Step 5: Solder the Voltage Regulators

There are two voltage regulators. One positive and one negative. The positive is the uppermost one on the pictures, the negative is the lower one.

Make sure that the regulators are mounted the right way. The metal "backside" must point to the right, when the board is oriented as on the pictures below. If they are placed wrong, the power supply will not work at all.

Step 6: Solder the 220 uF and 2200 uF Capacitors

The smaller 220 uF capacitor must be oriented with the white band pointing upwards. If you have decided to improve the voltage ripple, substitute this capacitor with the new one.

The four larger 2200 uF capacitors must have the white band pointing downwards.

Step 7: Solder Screw Terminals

The last components to go on the board are the two screw terminals.

The screw terminal with two connections is for the 15-18V AC input, from the wall adapter. The screw terminal with three holes is for the +/- 15V DC output and ground.

Orientation of the Screw Terminals

B0905 Cabinet: If you are using a B0905 cabinet, you really want the holes of the screw terminals pointing inwards. If you don't, you risk shorting the power cables against the wall of the cabinet.

If you have a lot of space in your cabinet, having the holes of the screw terminals pointing outwards from the board is normally the way to go.