Some photos of an amplifier that uses all directly heated triodes:
This amp can be used with 45 or 2A3 output triodes. The settings for the tube are selected by a switch. Also different input tubes can be used, either 801A and similar (10Y, VT25, VT62 ) or 26 (also UX226). In the picture above 45s and VT25s are plugged in.
This picture shows the amp with globe 45s (UX245) and globe UX226. The amp is not finally fixed to the frame, so some screws are missing. Also the bottom plate with feet is not attached yet.
For easy handling the metal plate which carries all parts is mounting into an assembly fixture. This allows to turn the whole assembly upside down or sideways without the danger of scratching the transformers or capacitors.
Then the capacitors and transformers are mounted. The second picture shows how the capacitors are fixed to the plate. The transformers used are Tango XE20S for the output and the Tango NC20F interstage.
This picture shows the wiring of the first level. All signal wiring is done with teflon insulated solid core silver. For mechanical protection of the fragile silver wire it is pulled through an extra insulation sleve.
The parts have been arranged for short signal paths. Therefor the input tubes are at the back, nearby the input jacks.
The driver tubes filaments are supplied with DC. The output tubes are AC heated. Therefor a filament transformer for the output tubes is placed inside the chassis (in the back row, center).
All the wiring is completed and the amp is ready to be tested.
The power supply still needs to be built. It will be placed in an extra chassis and built up in a similar style.
Here are a few more shots of the amplifier: