finished my last build inspired in the schematic of Doug over http://www.dougcircuits.com/neon.html
It also has a tremolo, but opamp based. The neon lamp wasn't working properly.
I'm using a greenback 10" speaker in this small cab, which used to have a transistor amp with two 6" speakers.
The schematic started with the AC4 with an extra 12ax7 for extra gain and ended with 4 different preamp configurations:
The series configurations EF86->12ax7->12ax7->EL84 really has a nice gain.
![Image](http://i.imgur.com/3clwYDS.png)
some pictures of the finished build:
![Image](http://i.imgur.com/d6D10C3l.jpg)
![Image](http://i.imgur.com/aWJM0vll.jpg)
![Image](http://i.imgur.com/K7t4B7pl.jpg)
![Image](http://i.imgur.com/udasCBJl.jpg)
![Image](http://i.imgur.com/UyJZtz9l.jpg)