All about electronic valves and hi-fi
I think a gain of about 130-140 should be ok. Perhaps if I get around in adding the 6SF5 stage then it may be good enough.
So this got me thinking. Of course I have on my list 2 driver tests:
Rod Coleman came up with a brilliant design recently which baptised as “shunt cascode” driver. For those who cannot stand a pinch of sand in their circuits, I suggest you skip this post now. This hybrid circuit is actually a folded cascode if we consider the book terminology. What makes attractive of this design is its outstanding performance against the classic multistage designs aimed at achieving a large drive signal for output stages such as 300B, 6C4C/2A3, etc. I personally haven’t build it yet but according to Rod the sound is superb.
Before building a stage which will replace my current 45 SE driver, I thought it made sense to analyse the circuit and understand why is claimed to be such a great alternative for today’s designs.