Both 6U5 and 6E5 tubes (NOS or good, bright used) seem to be very scarce at the moment – and very expensive when they are available. Have you considered a 1629 with a voltage doubler for the heater in the tube socket – works well. There are some suppliers of adapters on the internet, but it is very easy to do it yourself (see article on ‘Nostalgia Air’). I recently converted an EM34 eye tube in a Pye tuner to a 1629 (NOS at $14) – see photos.
- This reply was modified 9 months, 2 weeks ago by Gerry O'Hara.