Making of a 801A / 211 Amplifier, Part 3: Signal Chassis Assembly

Hi!

In the last post about these mono blocks I showed the assembly of the power supply chassis. Now we will see how the amplifier section gets constructed.

The metal plate with sockets and connectors:

The red jacks above the tube sockets are bias test points. At these the bias current of the tubes can be measured with a DVM.

The back side:

Mounting the transformers and oil capacitors:

Output and interstage transformers are original Hirata Tango production:

All signal wiring is done with solid core silver wire, protected by additional sleeves:

Adding some B+ and filament wiring:

Chokes, additional oil caps  and bias resistors are added on a tier which is mounted below the metal plate:

Below the driver tube socket in the top right corner there is space left to add an input transformer if needed. These amplifiers will be used with a preamp which has very high gain, so the input transformers are left out, but can be easily added later if needed.


The amp is ready to be tested:

After testing the amplifier will be inserted into it's wooden frame.

Impressions of the finished amplifiers will be shown next. Stay tuned!


Best regards


Thomas