In the past few weeks I have made progress on by OTL amps. The wooden bases are finished, and I am very happy with the finish.

I reformed and tested all the big can caps. The Nippon Chemi Caps are fine. The big old Samgmo caps make me too nervous to consider using them. They may be serviceable, but have a high leakage current compared to the Nippons and do not seem to hold a charge. Perhaps I'll use them in some other project. I will buy 2 x 2200 caps for each rail. 4 per mono and 8 in total. This caused yet another redesign of the top plate. I have now got room to place a big heat sink on top. It will disipate heat from bridge rectifiers and big resistors used for soft start.

Finally I started to build. While all point to point wired, the amps will be modular. I am using wood blocks as the base for each power supply circuit. I laid out the supply for the small tube anodes and wired them up. This way the caps are well supported and vibration damped....

I am starting this blog to create a record of my first tube amp project. The project is to build a pair of 110W 6c33c OTL monoblocks based on Bruce Rosenblit's patent. I am starting the blog at the stage that I am well into the project. I started planning and collecting parts well over a year ago and am at the stage where execution is under way.

So how did I end up with this choice? My DIY audio experience got under way with a Peter Daniel chip amp which I enjoy to this day. Along the way I discovered the Lampizator site leading to the creation of a 1541A DAC with 6np2 tube output. When this sprang to life I was hooked on the idea of building a tube amp. I have never actually heard a tube amp. The look is very fundamental. I want to experience the additional nuances in the music reported by tube amp fans.

I wanted to start with something simple but good quality for my first project. I also wanted to keep costs in check. I figured that good quality...