Find all your DIY electronics in the MakerShed. 3D Printing, Kits, Arduino, Raspberry Pi, Books & more!

276956384 Bc38B3C397

276956378 3D459C3E6B
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.

Related:

  • Altoids and tin cases Archives – Link.

Img413 1255
From the pages of MAKE:

Phillip Torrone

Editor at large – Make magazine. Creative director – Adafruit Industries, contributing editor – Popular Science. Previously: Founded – Hack-a-Day, how-to editor – Engadget, Director of product development – Fallon Worldwide, Technology Director – Braincraft.


Related

Comments

  1. dyfrgi says:

    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.

  2. ryanwm says:

    “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.”

  3. afaust says:

    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’.

  4. tsangal says:

    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).