Make suplay power circuit diagram for the best guitar

The power supply is again nice and simple, and does not even use traditional regulators for the preamp. The power transformer should be a toroidal for best performance, but a convention tranny will do just fine if you cannot get the toroidal.
power suplay for guitar

Do not use a higher voltage than shown – the amplifier is designed for a maximum loaded supply voltage of +/-35V, and this must not be exceeded. Normal tolerance for mains variations is +/-10%, and this is allowed for. The transformer must be rated for a nominal 25-0-25 volt output, and no more. Less is Ok if the full 100W is not needed.

The transformer rating should be 150VA (3A) minimum – there is no maximum, but the larger sizes start to get seriously expensive. Anything over 250VA is overkill, and will provide no benefit. The slow-blow fuse is needed if a toroidal transformer is used, because these have a much higher “inrush” current at power-on than a conventional transformer. Note that the 2 Amp rating is for operation from 220 to 240 Volt mains and as shown is suitable for a 200VA transformer – you will need an 4 or 5 Amp fuse here for operation at 115 Volts. Smaller transformers can use a smaller fuse – I am using a 2A slow blow fuse in my prototype (160VA transformer at 240V mains input), which seems to be fine – it allows for a maximum load of 480VA which will never be achieved except under fault conditions.