Building Compact F5 Amplifier (Part 1) Case And Power Supply

Having the compact case like this, I speed up my amplifier project to be starting soon. I look around what amp can I make with this kind of case and the result is will be no other than the F5 amplifier from Nelson Pass. It is class A, 2-stages amp, and running hot. Although this is not the typical big F5 amp cases, hopefully the heat is not an issue.

I checking the components lying around my shelves and take whatever it takes to make this amp. I also reparing the board for the capacitors rack.

Measure all components position before soldering.

The resistors on the side of the caps are the filter resistors. See also the bleeder resistors are hide between the caps. They are 5 watt 2,2k ohm each.

At the bottom side is the simple point-to-point wiring made from the lead of the resistors.

On my hand, I have 225 Va toroidal transformer. I think it is quite small for stereo F5 amp but I will using this transformer for awhile.

I finished wiring up the input AC voltage to the fuse and to the power switch.

This original Halfer case using power switch from Shinden Japan. The quality is awesome. Looking by how long it service in this amp and until today it still working flawlessly.

I also look no other rectifier bridge then using from the original Hafler case. I believe the quality are also the best.

Apply the thermal grease is not necessary anyway.

The next step is put the toroidal inside the case and hook up the primary winding to the AC power line.

Then I hook up the secondary winding to the rectifier bridge and continue to the capacitor board.

It is now I can check DC power output.

Preparing for the next step is for speakers output and grounding.

See how messy under the board. Full of cables.

Until the board is flip to its place, now the cables are hidden and all power supply steps are finished.

Part 2 can be find here

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