Here are some pics of a recent restoration project carried out on a classic Oz amp, the Goldentone Six. It is one of those rare beasts, a genuine stereo amp.
This is the amp as it was found, after spending ten years under a house. A previous owner had painted the original vinyl black, and had varnished over the paint. The original vinyl colour can be seen at the back left. The circular swirls on the grill cloth appear to be original, but the diamond pattern has been painted later - the paint has gone through to the speakers. The handle is definitely not original.
The cabinet is 19.25" H, 22.25" W, 7" D.
The owner's brief was to check the amp, and make it electrically safe, but to leave the character of the amp as it was found.
The name of the amp is now obvious - Goldentone Six. Six x 8" Rola speakers. The top panel has been removed to show the open chassis design (a major electrical hazard, since there is no bottom side to the chassis). Note the separate power supply connected by an umbilical. Apart from the Marshall style LCR blue capacitor on the power supply, all components are original.
Hammond two-spring reverb tank on the left hand side. The reverb tank is connected in parallel with one set of three speakers, and then feeds into the second channel.
The amp could be run as a stereo amp, with the guitar plugged into the tremolo channel, which also fed the reverb. The reverb then went into the second "clean" channel.
Alternatively, the two channels could be "mono'd" together at the inputs, using a pull switch on the front panel.
This is a stereo 20 watt + 20 watt amp, with each power stage driving three of the speakers.
Genuine coffee cup stain, but I don't know what happened to the paint and finish just above the handle. But it's now a permanent feature!
The amp's control panel shows promise.
The amp after a good dust and a clean. The original grill pattern can be clearly seen, as well as the added diamond pattern.
At the owner's request, the amp has been cleaned up but no cosmetic restoration has been done.
The amp's internals, after the clean up. A clear perspex panel has been added to make the amp safe. Speaker sockets, a footswitch socket and tremolo switch have been added to the perspex panel.
The only components that needed to be replaced were the main 47uf + 47uf cap on the power supply, and two power caps (the blue ones seen here).
Each speaker has a new Rola label.
This is the cleaned up control panel. The artwork was painted in reverse on to a clear perspex panel. The quality of the art-work is extraordinary, and the art deco design is certainly unusual.
The amp has volume controls for both channels, bass and treble controls for each channel (dual log pots), and a pull switch on the left side Volume control to connect the inputs of the two channels together.
The Tremolo Speed knob is also the power-on switch
This is the Goldentone badge.
RM is Rose Morris, a Melbourne company.
Here's the top view of the amp and power supply with 4 x 6GW8 pentode/triode power valves (cathode bias) and 2 x 12AX7 input valves.
Solid state power supply.
Two twenty-watt amps, with reverb and tremolo.
Here is a close up of the tower build technique. No component board to be seen.
A bolt was passed througth the centre of each valve socket, with a second valve socket mounted on the top of the bolt. This allows a 3D construction style, with reasonably short component lead lengths. Access to replace the components on the valve nearest the pots is not the best, but on the other hand, none of the components has suffered any heat damage.
The component quality can be seen, as well as the dual pots for the treble and bass controls.
Goldentone Six Schematic