One of the first valves I traced with my curve tracer was the 6E5P/6Э5П. It has a very good reputation when triode-strapped. I did many tests and found this one being a superb driver given is one of the most linear valves out there. Many use them as a 300B driver. I will probably implement Rod Coleman’s shunt cascode topology in my 45 SE or in a 6C4C/4P1L PSE design.
Over the weekend I traced many valves as managed to recalibrate the oscilloscope and tracer and wanted to play with some samples I had around.
Here is the 6E5P/6Э5П in triode mode:
Now, let’s have a look at it’s close brother the 6E6P-E/6Э6П-E in triode mode. It has a long life (10,000 hours against only 500hours):
Many praise the 6e6p-DR tetrode over these two, I haven’t tried it yet myself but here are the minor differences between 6E5P/6Э5П and 6E6P-E/6Э6П-E to highlight:
- Both 6E5P/6Э5П and 6E6P-E/6Э6П-E have very linear curves!
- 6E5P/6Э5П: less anode resistance and higher transconductance compared to 6E6P-E/6Э6П-E which seems to have a tad more of gain