The New 45 Drives 45 Mono Amplifiers

Hi!

It's been a while since I built 45 power amps with 45 as driver tube.

Here a pair of newly finished amplifiers in that configuration.

About to be shipped to their new owner in the US.

The amplifiers use a 45 in the single ended output stage, delivering about 2W.

The output tube is driven by another 45 through an interstage transformer.

The input transformer offers the possibility to have a balanced XLR input.

The amps have been constructed in the tower style chassis using all the latest construction techniques which evolved over the years.

A few photos showing the construction process, starting with the raw top plate.

Sockets and meter mounted:

Some components are mounted underside of the top plate via threaded blind holes:

Initial wiring:

Adding the capacitors which are closest in the signal path:

Interstage and output transformers reside on a separate sub assembly along with more capacitors and chokes:

The power supply section:

LCL filtered filament supplies for zero noise operation even on the most efficient speakers.

Adding the sub assemblies layer by layer, with additional plates in between for mechanical ruggedness:

The completely assembled amp, without enclosure, ready for testing:

Some more pics

Best regards

Thomas