This is my first non-Triode project. I was intrigued by the 807 tube, which is a Tetrode and decided to make one. The first 807 tube I got was a Westinghouse brand which sounded weird. It's so thin and lean and doesn't impress me at all. I thought that it's the 807's character. Fortunately, I was able to get my hands on a pair of RCA 807 and that sounded real good! However, my prototype is not optimized as I have problems in stabilizing the voltage for G2. I used a voltage divider, a string of zener but still there's something missing (bottom end) from this amp.
Here's the picture of the 807 prototype-
It was at this point that I pulled out a Hammond 1628 that I purchased from another friend. I wanted to try using the UL tap and decided to make an implementation of Gordon Rankin's 807 amplifier as featured in Sound Practices.
Building the amp was relatively easy as it has very few parts. Here's the underside of the amp with the wiring and parts reasonably visible.
Here it is playing some music in my system. I really like the purple glow of the VR tubes!
