Day 030/17. Dedicated to sound.....

One of the photographic benefits of working in a technology company is that whenever I run out of 365 ideas, I just wander around in the software developers area and usually find something.
Today I found this..... It's an amplifier.... but not just any old amplifier...... This uses a single valve (the glass thing to the left)...... and I am totally convinced if I asked exactly the benefits of it, I would be there for an hour at least, probably with a white board diagram to assist my understanding.