Check all exposed metal for less than 1 ohm of resistance to the center terminal of the power connector. Leaky insulation in a transformer, or capacitor could put lethal amounts of electricity on the case, the volume control, the speaker wires, or the input jacks (electrifying the case of your CD player). A shorted transformer could be LETHAL if not grounded, there could be hundreds of volts on the case. VERIFY this connection with an ohm meter BEFORE powering up the amplifier. Any metal object that can be touched MUST be connected to the GROUND terminal on the power receptacle. The grounding is very important to make the amplifier safe and eliminate hum. Input connections without a volume control. The switch must be rated for operation on the power line in use in your location.Īdding a supplemental capacitor to the power supplyĪdding a switch to choose SS or tube rectifier. This diagram requires the use of a fused IEC power receptacle. The standard wiring connections are shown.

The black wires are the primary connections. These terminals are located on the rear of the board to keep the AC away from the sensitive areas of the PC board. They are connected to the T1-grn terminals. The green wires are the 6.3 volt filament wires. It is connected to either of the T1-red-yel terminals, or to the standby switch if one is used. The red and yellow wire is the center tap for the high voltage winding. The center terminal on this connector is not used. They are connected to the terminals marked T1-RED. This circuit is connected to B+ and can not be used to power anything else. Make no other connection to these wires or terminals. They are connected to the terminals marked 'T1-YEL'. The yellow wires are the 5 volt rectifier filament winding. Most power transformers use this standard color code for the wires. The above diagram shows how to connect up the power transformer. The optional components (standby switch, rectifier switch, choke, supplemental capacitor, UL / triode switch, and CFB switch) can be used individually or in combination. I have added two diagrams as viewed from under the chassis at the bottom of this page. This is how everything would look if you were using above the chassis mounting. These are all shown as viewed from the top of the PC board. The following diagrams illustrate how the individual external connections to the PC board are made. Several popular hookup configurations for the completed amplifier are presented as well. Wiring for each external component is covered. In many cases this can be completed without soldering. This page contains pictorial wiring diagrams for the connections from the PC board to the external components.

Transformer wires color coding