Electronics

Here you can find information and schematics for some of the projects I've done.  They are categorized, as follows:

• Automotive Electronics - calibrations and toys
• Electron Tube Audio - tunes via fire bottles
• Home Automation - make your house kinda smart

Tubelab SE Breadboard

Posted on March 16, 2009.

So I've finally built-up this Tubelab SE, a small, single-ended, 2 watt amp.  It's currently in breadboard form, but it sounds amazing.  Awesome detail, impressive bass, and something warm about the sound.

Tube Fluorescence

Posted on February 04, 2009.

These are the output tubes on my Thomas amp.  You can see the blue glow against the glass from stray electrons.  This is very common with Sylvania tubes.  Behind the blue glow, is the red glowing line from the electron beam hitting the plates (I can’t get the bias to go any lower with this amp).  The two together look purple to the camera.

I have read contradictory discussions about blue glow against the glass envelope.  Blue glow coming from inside or near the anode or other structures is normal, but some say that blue glow outside of that means a soft vacuum.  Sylvania claims the opposite and that fluorescent glow inside the envelope is normal for some tubes.  It results from stray electrons bombarding near the glass envelope and will change in brightness depending on the intensity of the signal passing through the tube.  This is exactly what I see with these Philips JAN tubes, which are basically Sylvania.  In fact when I push the amp really hard well into cut-off, the tubes will flash brightly signaling me to back-off

The "Winged-C" SED EL34s in the Dynakit seem to fluoresce at the screen behind the plate:

Made in Chian

Posted on January 29, 2009.

All the best stuff comes from Chian.

Blueberry 60.17

Posted on September 16, 2008.

09/16/2008: Version 60.17 (based on "Blueberry60") - Add timing back to AdvanceFromMapWarmFull so that retard window is from 2.5 - 10psi.  Also add a couple of degrees before and after that.  Scale FuelMonitorScaling down instead of up (duh) to try to match observed mileage.  Set StartFuelCompBaro back to stock to try to address insufficient fuel at cold start.  Change AdvanceFromRpms under 1500 back to original BB60.

Blueberry 60.16

Posted on July 07, 2008.

07/07/2008: Version 60.16 (based on "Blueberry60") - Revert ColdEnrichmentFuelCurveA back to stock since AIS changes seemed to address part of lean startup conditions.  Remove more timing from AdvanceFromMapWarmFull to widen range down to -2psi.