Seven-valve amplifier

This is from the same spot (Makezine) that hosted Mr Still’s unicycle snow-chains article; it’s a seven-valve (counting the dual-half-wave rectifier valve as one valve, and counting a dual valve as one valve) monauraul audio amplifier built for Albert Einstein’s 70th birthday.

It’s a very simple, clean design (uses many dual valves, appears to have ClassB power output) but I shudder to think about items like intermodulation distortion, not to mention basics like hum, total harmonic distortion and pure efficiency.

It’s here because it makes an interesting contrast with (say) a fingernail-sized Flash media player or a tiny sound-card which not only does the same thing — in stereo or quad, at least — but almost certainly at a much higher quality.

(Possibly except for the actual music itself) it’s a reminder that the good ol’ days are good primarily because they’re old, so we don’t have to put up with them any more. Imagine how large your Athlon-powered... um, laptop would be with this techology in it!

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new life for an old (FTX) PSU, improved life for one human

the LEDs on this 5m strip happen to emit light centred on a red that does unexpectedly helpful things to (and surprisingly deeply within) a human routinely exposed to it. it has been soldered to a Molex connector, plugged into a TFX power supply from a (retired: the MoBo is cactus) Small Form Factor PC, the assorted PSU connectors (and loose end from the strip) have been taped over. the LED strip cost $10.24 including postage, the rest cost $0, the PSU is running at 12½% of capacity, consumes less power than a laptop plug-pack despite running a fan. trial runs begin today.

every-application-is-part-of-a-toolkit at work

I have a LibreOffice Impress slideshow that I wish to turn into a narrated video. 1. export the slideshow as PNG images (if that is partially broken — as at now — at higher resolutions, Export Directly as PDF then use ‘pdftoppm’ (from the poppler-utils package) to do the same). 2. write a small C program (63 lines including comments) to display those images one at a time, writing a config file entry for Imagination (default transition: ‘cross fade’) based on when the image-viewer application (‘display,’ from the GraphicsMagick suite) is closed on each one; run that, read each image aloud, then close each image in turn. 3. run ‘Imagination’ over the config file to produce a silent MP4 video with the correct timings. 4. run ‘Audacity’ to record speech while using ‘SMPlayer’ to display the silent video, then export that recording as a WAV file. 4a. optionally, use ‘TiMIDIty’ to convert a non-copyright-encumbered MIDI tune to WAV, then import that and blend it with the speech (as a quiet b...

boundaries

pushing the actual boundaries of the physical (not extremes, the boundaries themselves) can often remove barriers not otherwise perceived. one can then often resolve an issue itself, rather than merely stonewalling at the physical consequences of the issue.

Plantagenet Penguinista

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