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Sunday, August 9, 2015

211 -The Next Generation- Part 5 : 211 Drives 211 Amp Assembly


In the last post about the 211/211 amplifiers I showed the construction of the power supply. In the meantime the amplifiers are finished as well.

Assembly was done top down, starting with the top plate, here shown with the tube sockets, resistors and input transformer attached:

Next level with some capacitors:

Interstage and output transformers are mounted on a sub assembly along with the high voltage paper in oil capacitors:

The sub assembly mounted to the main assembly and wired up:

Filament and B+ chokes are on a separate plate:

They are at the bottom of the amplifier:

The terminal plate with separate power supply connectors for high voltage and filament, Speaker terminals and input connectors:

The terminal gets provisionally mounted to the amp for testing:

The amp with tubes pugged in:

Now only waiting for the wooden enclosures to be finished.

Stay tuned for the next part which will show the amps and power supplies in their enclosures.

Best regards



  1. many thanks....please advise what voltage you are driving the 211 valve with and your aimed ma bias for the valve.........love your 211 projects...
    .....compliments for your knowledge, your craftsmanship and your skill

    regards Frank

  2. Hi Frank, you need to chose your op point so that it matches the design choices entire amp, especially the output transformer. see my post about operating points here for my philosophy on this topic: