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Saturday, May 4, 2013

Two Single Ended 45 / 2A3 Amplifiers


Two more 45 / 2A3 amplifiers finished. A two chassis amp (stereo with external PSU) using a directly heated driver tube, either a 26 or 10Y. And a single chassis amp with indirectly heated driver stage.

Both amps can be configured for using either a 45 or a 2A3 as output tube.

The two chassis amp uses Tango interstage and output transformers.

The PSU uses my usual bridge rectifier configuration with 4 6AX4 TV dampers working into a choke input filter.

The single chassis amp uses Lundahl interstage and output transformers.

This amp uses a bit simpler power supply with 2 6AX4 TV dampers.

The circuit is similar to the one of a 46 amplifier which I presented some time ago.

Some close up shots of the amps:

Best regards



  1. how much does the 2 chassis version cost ? Thanks

    1. There are different options for the two chassis version. Please contact me by email or phone for pricing. The contact information can be found here: