Eico HF12 Restoration
I was sent in 2 HF12's for a complete restoration-which included complete removal of everything-similar to the HF81 page and completely clean and install all new tube sockets, components and a complete rewire.
In the pix you will see the original units shipped to me and then some pix showing progression of the restoration.
Since the HF12 on/off switch is mounted to the treble control similar to the HF81, it will eventually wear out as it did in one of these plus it takes a lot of wear on the pot.
So I first off removed the old ac receptacle at the back and enlarged it and installed a modern IEC AC female plug. Moved the Hum pot to the front , installed an on/off switch in the back and also a fuse holder.
Similar to the HF81 restoration a 6x2 input selector switch was installed. Filter cap was replaced with a 33uf/450 for the first section and then a can cap of 50uf/50uf @500v.
The resistors in the signal path are all carbon film, and Kiwame 2 watt on the plates. Coupling caps are PIO K40 Russian. The rca jack plate was constructed with gold jacks and gold binding posts for the speakers connections with
GRND, 4 and 8 ohm connected. The RIAA components were installed around the phono tube.
Very nice looking amps now and sound amazing....