![]() ![]() For me, Butler captures something incredibly important, a trajectory for our tired and bruised little species, and the Parable books (there are two), offer up one that I think Carl Sagan would be proud of - that our destiny (if it makes sense to say that we have one) lies out there, among the stars. I’m always looking for more pieces to add, more colors to draw with, more big ideas, more history, more this and that - anything, really - anything that would add more life to the words I’m trying to summon out of the fog of daily life. My day job is something of a puzzle, to be fair. Especially when my head gets yanked around by change. It’s a good book, for the record, and one I quote from often in my day job. Her Parable of the Sowerwas published back in 1993 and has the distinction of coining the phrase “Make America Great Again” and using it in a presidential campaign. Octavia Butler once wrote that “the only lasting truth is change”. So, with that said, lemme tell you about my problem. I think there are lots of you out there trying to do truly dumb stuff - dumb stuff exactly like what I’m trying to do here. Maybe an audiophile-adjacent problem, but I don’t believe so. Just want to be clear.Īll of this is me trying to solve a problem. UL operation requires either a UL transformer, or more complex circuitry.Īnd that is just another part of the continuing story of tradeoffs.What follows is not a typical audio review of the Naim Uniti Atom, or, of anything really. It is a function of the cathode impedance versus the self bias resistance. The disadvantage is that the tube does not control its own current as well as it would when all the bias voltage comes from only self bias circuitry. Using a combination of Adjustable Fixed Bias, plus some self bias also works.īut the resistors for the self bias have lower resistance, since most of the bias voltage is from the adjustable fixed bias circuit, and not from the self bias resistors. But you have to adjust by going back and forth to match all 4, unless the B+ is Regulated. Individual Adjustable Fixed Bias also works, as long as you can adjust each individual tube current. There also was no easy way to notice if one 6V6 was very weak, or if instead all 4 6V6s were each a little weak.Ĭhanging to individual self bias resistors changes all of that, but does work.Ģ4V / 37.5mA per 6V6 = 640 Ohms for each 6V6 cathode resistor (less watts / resistor).Īnd you have to find room for 4 bypass capacitors (modern ones are smaller now for the same voltage and capacitance ratings than they were when the A300 was produced).īut now you also have to provide 12.6 VDC 300mA for the two 12AX7 filaments The relatively small output transformer that had one strong 6V6 and one weak 6V6 was near saturation even before any bass signals were applied, due to the two un-balanced plate currents. None of the crowd noticed that the Casket almost tipped over.ģ strong 6V6s, and 1 weak old 6V6 were biased with a common cathode resistor, consisting of two 12AX7s filaments in series. The 3 strong ones had to make up for the 1 weak one. One, on the Left front of the Casket was 95 years old, and very frail. The output stage bias circuitry makes me think of the following analogy:Ĥ persons were honored to carry a small Casket of their good friend who passed away.ģ were young and strong. I do not have a schematic of the XAM either, so I can not comment on its bias circuitry. I do not have a schematic of an HK500, so I can not comment on its bias circuitry. ![]()
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