I first announced this SET on September 18th, 2020. It’s only taken me about 19 months to get to this point. To be fair, that 19 months was fairly eventful, including both my retirement and much of the COVID madness. But tomorrow, the slow methodical process of testing can finally begin.
Continue readingAlthough sometimes it may take a little disturbance to the system, as it turns out, you can teach an old dog new tricks.
Continue readingWith all the distractions this week, I’m not quite as far along as I would have hoped. But all the top plate wiring is done, the power supply sections are complete, and the 6AS7 power stage is complete.
Continue readingI just posted the project page for the 12AU7 “Color” Preamp which I completed a couple of months ago. Why don’t you go check it out.
I really haven’t had as much free time this week as I thought I would. But, in spite of other tasks taking priority, I’ve managed to get the iron for the SET all wired into the top plate.
Continue readingI managed to make good progress on the assembly of the 6AS7 SET today. In addition to getting all the hardware and iron mounted in the chassis and on the top plate, I’ve actually started wiring.
Continue readingI managed to eke out a little time to work on the 6AS7 SET top plate this afternoon. I didn’t get a lot done but at least I’ve finally started.
Continue readingAfter many delays and distractions I have finally finished the 6AS7 SET chassis and have begun assembly.
Continue readingI currently have a couple of major projects on the workbench and a few other minor tube circuit investigations underway. When this happens I find myself pulling things off of shelves, moving other things around, and generally creating quite the mess until I’m having problems finding just about anything. When this happens I generally step back and take some time to get everything organized again. But this time, I wasn’t quite prepared for what I found.
Continue readingIt’s been a productive few days. Two different amp projects are coming along nicely and today I’ve reached a milestone.
Continue readingThese last few days I’ve been working on the driver stage and overall schematic for the new 6L6 SE-UL amplifier. While drawing up the schematic yesterday, I inserted a 250kΩ volume control at the input without much thought. While performing some preliminary analysis, I realized my mistake.
Continue readingFor the last few days I’ve been applying oil to the SET chassis. It now has four coats of oil, cured and buffed out. There’s only one decision left for the chassis.
Continue readingToday I was once again reminded of the perilous state of human fallibility and the risks of personal hubris. The cost of today’s lesson? One ruined KT-88. And a little smoke in the office.
Continue readingThis morning as I sat down in my office to check email and the like, I looked over at the amp in the corner of the room and made a snap decision. It was time to perform a SET swap.
Continue readingThis afternoon I’ve been working on another amplifier project. This particular one is the 6L6 SE-UL for which some readers have been looking since I published my Optimization of the 6L6 SE-UL page back in March of 2019. I recently realized that it had been three years since I published that data set and that it was probably time for me to get the project started. So this afternoon I’ve been investigating driver stages for the amp.
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