Archive for February, 2014

Oh Sheesh (school, guitar amp, dogecoin, etc.)

February 5, 2014

I don’t seem to blog much right now. Since school has started again maybe my routine will work out so that it happens more. School is dumb this semester. I was too anxious to talk to all the right people to get signed up for the difficult things I need to do to graduate, so I’m just doing the easy things. Despite the things being easy, I am currently writing this post while procrastinating on something due at 8AM tomorrow. Such is life, I guess.

I finished the amp from last post. It is wonderful and it is loud. It still needs a tiny bit of troubleshooting:

  • Hum, probably from heater current. DC elevation didn’t fix it, nor did switching out the center-tap ground for a virtual ground. The heater wiring can be shortened but I haven’t gotten around to doing it. I could also reduce the total current.
  • The preamp plate-starve control does nothing. It varies the preamp supply voltage from 300V down to 150V as I planned–however this doesn’t affect the sound AT ALL. Apparently none of the amp’s distortion is actually coming from lack of plate headroom. It’s also possible that this control is bleeding hum into the signal, but it seems unlikely. This control will be removed, but I might put a master volume in its place.
  • The “snappiness” control is wired backwards, it seems. I’m gonna leave it.
  • If the second boost switch is enabled and the volume or tone is set at 8 or higher, very loud crackling and feedback occurs, in addition to small white sparks visible at the top of the power tube. Adding series resistance to the bypass capacitors didn’t fix the problem. I’m thinking about adding series resistance to the power tube grid to see if that helps. If it doesn’t, I’ll just rewire the knobs so that 8 is the new 10. :)

Soon I will take pictures and possibly video and make audio recordings, but I’d kind of like to fix these issues first.

The other thing I have been “into” recently is dogecoin mining. I’m getting about 100KH/s but I only made a $50 investment into gear, so whatever. So far I’ve made back about $15 (actually Ɖ11,000)  but I’m planning on holding until the price goes up. The inflation rate is going to halve in almost exactly a week, so that’s interesting.

What have you guys been “into” recently?

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