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 Simple PP

Posted on April 29, 2010.

George from Tubelab was kind enough to send me his latest PCB and some iron for a test build.  Easy build and the result was tossed into a disused lock box.

Simple SE - Fire in the Bottles

Posted on May 05, 2009.

It's finally done.

more

Tubelab Simple SE Chassis Fitting

Posted on April 17, 2009.

All of the cutting and milling and drilling is finally done.

Here are all the various bits and pieces, made mostly from scraps, all put together:

More about the build here. Next step is paint....

Tubelab SE Breadboard with 300Bs

Posted on April 15, 2009.

With a custom power transformer from Edcor, I could finally try this amp with some borrowed 300Bs.  This transformer's primary is tapped so that it can be used with either 300Bs or 45s:

XPWR131 - 330-260-0-260-330 @ 175mA, 6.3 V CT @ 4A, 5V @ 3A

Voltages came in a bit high, even under load.  The top row is the Tubelab SE in "45 mode", with about 25mA per tube.  Meters are reading: 660VAC winding, 520VAC winding, B+ at the filter cap.  Bottom row is in "300B mode", running Shuguang 300Bs (not mine) at about 28mA per tube.  First two meters got swapped: 520VAC winding, 660VAC winding, B+.

With the 300Bs biased to 80mA, the 660VAC winding gets pulled down exactly to spec: 660VAC.  B+ sags to around 370-375 VDC.  Supposedly this is the ideal spot for the 300B.  These tubes are Shuguang's aptly-named "300BS", which have mesh plates and globe-shaped glass.  They have a weird blue glow on the glass, presumably from electrons flying through the gaps in the mesh.

Tubelab Simple SE Breadboard

Posted on March 22, 2009.

With the right iron, the Tubelab Simple SE comes to life.  After a sanity-check with cheap Chinese tubes, here is the amp running with JJ 6L6GCs strapped as triodes.  The amp sounds sweet with a bit more power than the Tubelab SE.

This coincides with the new speakers that I recently got off of Craigslist: a pair of Klipsch KLF-10s.  The horns on these do cause ear fatigue on the Dynaco, but with this amp it is more subdued.  I am hoping that the DHTs in the Tubelab SE will be even better.

The basement in currently under construction, so the setup is a bit MacGyver.