The arrival of the output transformers today gave me the impetus to finalize a few things in the 6AS7 SET design. So now I have a complete schematic with all the important information noted on it.
Continue readingSET – Step One
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No More Excuses
One simple sight that really gets me excited is to see that very heavy box sitting on the front porch. Today, the output transformers for the 6AS7 SET amp arrived from Edcor.
Continue readingOther Projects
There is one thing about vacuum tube amplifiers that sometimes gets in the way. They are not exactly what one might call portable.
Continue readingNew SET Coming
As I discussed in my last post, there is a new SET amplifier on the horizon. This SET will sit midway in power and performance between the little SETs (6CY7, 6CY7 V2, and the 6EM7) and the big 6336 SET Amplifier.
Continue readingDesign Decisions
So with the 6CY7 V2.0 Zebrawood amp finished and my 6L6UL project on the back burner, I’ve been working on a new SET amplifier. I have been thinking about an amp somewhere between my small SETs and the big 6336 SET amp. But I’ve run into a hiccough.
Continue readingA/B Testing
I was arranging some things today in preparation for an event this evening and happened to have a little Class-D amp in my office that I normally use in my wood shop. So I decided to try a little A/B testing.
Continue reading“Experts”
So I was reading one of the tube forums recently and I saw an amp builder who, when talking about his latest build, said “To my ears sounds nice but I am not an expert”. Now I read or hear variations on this theme all the time. And frankly, it upsets me greatly.
Continue readingIntroducing the 6CY7 Zebrawood
So it’s been a while since I first grabbed the plank of Zebrawood in my shop and envisioned it wrapped around an amplifier. That was June 13th. Here it is a little over two months later and I now actually have a functioning amplifier. I have to say I’m pretty happy with how it turned out.
Continue readingSlow Progress
As some may already know, I’ve been working on a new version of the 6CY7 amplifier. There is a new chassis specifically designed for this amp and some circuit changes to improve performance. But here’s the issue, I can’t seem to get much done. Let me explain.
Continue readingA Small Change
I have made a small change to the website which I hope will be helpful.
Continue readingWaiting for Paint
So I’ve had the chassis and metal done for the 6CY7 V2 amp since the 4th of July. It has now been a full 13 days and… the paint is not yet fully cured. It is hard for me to remember it ever taking this long for a semi-gloss enamel on metal to cure hard enough to begin assembly work. Obviously the manufacturer has changed the solvent makeup of the paint I use. Time to find another manufacturer. In the mean time, I’ve been working on other things.
Continue readingTube Tools
Like everyone else all over the world, for the last four months I’ve been working from home and limiting my trips out out of the house. But the situation these last four months has not been entirely unwelcome (except of course for people getting sick). For one thing, the view from my home office of trees and mountains is immensely better than the windowless building in which I was working. And for another thing with no commutes and flexible schedules, I have gained several additional hours in my day for doing things I want to do. With all I new found time, I did what any responsible technical person would do in such uncertain times. I’ve been teaching myself some new skills.
Continue readingWood and Metal
Well, the new version of the 6CY7 amp is coming together. The wood for the amp has gone from a raw 11″ x 58″ plank of Zebra Wood {Microberlinia brazzavillensis} into a finished amplifier chassis complete with four coats of Tru-Oil finish. I think it looks pretty good.
Continue readingChange is Good
I want to start by rolling the clock all the way back to March 6th of this year. It was Friday and I had just returned from a business trip the night before. That afternoon (Thursday) my employer had decided that everyone was to start working from home immediately. Not wanting to try performing complex engineering tasks with only a laptop screen, I immediately ordered two nice high definition 24″ monitors. But the question was where to put them. The “answer” was, on my office desk where I usually do tube work, including prototyping and assembly. This gave me a good spot to do my job, but with two large monitors and their ample stands, it left little space for power supplies, oscilloscopes, signal generators, and other such trappings of my vacuum tube amplifier work.
Continue readingA Productive Day
So I usually have multiple amp projects going on at any one time. There is a rather large project that I’ve been working on but it’s going rather slowly and I was hungry to make some progress on something. As such, I decided to tackle a smaller project I first prototyped in 2011 and that has been on hold since 2015. I spent the better part of today turning an 11″ x 58″ plank of Zebra Wood {Microberlinia brazzavillensis} into an amp chassis.
Continue reading