Discontinued, but hopefully will return in a new form.

This is a design based on the original UA1.0 The very first UA amp or ugly amp as we called it, looked more like a high school science project than a properly made audio tube amplifier. It's output was 4.5watts of power into 8Ω. The switch closest to the black volume control knob was a global negative feedback switch. This increased the damping factor allowing this amp to drive more difficult load in speakers with more complex crossovers.

The tubes used in this amp were a Russian EL84 variant the 6P15P, this is the most dynamic tube I have ever heard or worked with in pentode mode. The 6P15P pair of tubes were driven by a 6N6P dual triode, which has a balanced neutral, yet lively sound. The most difficult aspect of this design was taming the 6P15P tube beast. It was wildly dynamic, but along with this came a huge amount of distortion, causing the amp to sound really harsh. On some recordings of guitar and a single vocalist it was so dynamic that is sounded so real you wondered what it would be like with other music if we could just tame that harshness. As time when on little by little I was able to lower the distortion to the point that it barely if at all had a harsh or shrill character. That is when the UA1.5 amp was born, a sweet but dynamic amplifier.

Its only draw back was that the tube with the required output transformer's primary impedance for lower distortion produced less bass at below 80Hz, even though the transformers were made to go as low as 40Hz at full power of 10watts. Meaning that the amp at 4.5 watts of power should go to 30Hz or lower. And although it measured well above 80Hz still it sounded a bit on the lean side. So you end up with a tube that has a sound leaning toward the thin side, but some may find the dynamics and realism so compelling they don't even notice or care. Building and having multiple tube amplifiers is fun and exciting as you can make a song or music in general sound completely different because of the distortion signature of the amplifier. Each tube has its own sound, and each way you set it up in a circuit has its own sound, and each output transformers has its sound, and this coupled with the speakers impedance plot, you have a seemingly endless amount of sonic possibilities. Add to that switchable feedback loops, and things get really fun and interesting.