MAKE Flickr photo pool member Tsangal made a nifty switchbox with volume knob and jammed it in an Altoids (the project box of choice for Makers). The title of the project is passive pre-amp, but I’m not sure where the amping is being amped – Link.
- Altoids and tin cases Archives – Link.
From the pages of MAKE:
- Mint-Tin Amp – Pocket amplifier punches up headphones, this one I know exactly where it’s ampin’. MAKE 04 – Page 131. Subscribers–read this article now in your digital edition!
8 thoughts on “Altoids switchbox”
It has input selection and a potentiometer, presumably audio ramp. I’m not entirely clear on the wiring, but it looks like it might have switchable input and output. A slightly odd way to do it, but I’m sure there’s a reason.
“Passive preamps have gained popularity in high-end audio circles. Provided that a high quality volume control is used, a passive preamp is often the easiest and cheapest way to reach high-end sound quality.
Actually, the term “passive preamp” is slightly misleading. The word preamp or preamplifier is not supposed to be a passive device, as a passive device may not provide amplification. So a better term than passive preamp would be passive volume control or passive control center.”
yeah, it looks like input and output selectors, with a potentiometer. I guess that could be useful, especially if you’re testing speakers and sources.
The ‘passive pre-amp’ name means it just makes line-level adjustments to the signal before it gets to an amplifier. In this case it’s just a volume control, but you could also have various filters or equalizers. If it’s got no ‘active’ parts requiring power, i.e. no transistors or op-amps (or tubes!), then it’s ‘passive’.
Yeah, I threw in an extra output switch even though I didn’t really need it. I’m currently using it to control the volume from my DVD player’s line out into my computer speakers (I also have a desktop and sometimes a laptop all hooked up to the speakers).
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