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Half a century ago, vacuum tubes were very common in audio amplifiers. A small voltage applied to the grid of a vacuum tube controls a relatively large current that drives the electromagnet in a speaker, creating movement and thereby sound. Modern solid-state amps are superior in cost, size and reliability, but many people still prefer the warm sound and mesmerizing orange-yellow glow of a tube amp.

Fortunately, there’s a way to combine the distinct sound and look of tubes with the utility of an iPod dock. I’ve seen a few commercial and DIY tube-amp docks, but they’re expensive, uninspired or both. So I’ve come up with a version that anyone can build for about $400.

It uses a number of off-the-shelf components, including the dock itself and an easy-to-assemble tube-amp kit for the heart of the system. I used the 16LS kit from s5electronics.com, but there are many options depending on how much money you want to spend and how loud you want the amp to be. I built my dock into an aluminum enclosure from Hammond Manufacturing. You can replicate mine or design your own.

Once you’ve made those choices, the most time-consuming part of the project is putting holes in the enclosure and mounting the components. Add a set of speakers, and you’ll have a functional and cool-looking amp you can control with a remote. It isn’t outrageously loud, but it will easily fill a living room with fantastic sound.
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Here’s how to build your own tube amp._ Complete build instructions and diagrams are available here.

<strong>Step 1</strong> Assemble the 16LS tube-amp kit. <strong>Step 2</strong> Connect leads to the amplifier. Modify the audio cable that comes with the iPod dock, and solder leads to the amplifier inputs. Connect leads between the volume control and the circuit board.

Audio Cable

Step 1 Assemble the 16LS tube-amp kit. Step 2 Connect leads to the amplifier. Modify the audio cable that comes with the iPod dock, and solder leads to the amplifier inputs. Connect leads between the volume control and the circuit board.
<strong>Step 3</strong> Prepare the enclosure. Lay out and machine holes, and mount the iPod dock and power supply with epoxy. Extend the leads on all the transformers and mount them on top of the enclosure, passing the wires through grometted holes.

Enclosure

Step 3 Prepare the enclosure. Lay out and machine holes, and mount the iPod dock and power supply with epoxy. Extend the leads on all the transformers and mount them on top of the enclosure, passing the wires through grometted holes.
<strong>Step 4</strong> Install the board in the enclosure. Note where the power and transformer leads connect on the underside of the board so that you can wire in the transformers after the circuit board is installed in the enclosure.

Top of Side Board

Step 4 Install the board in the enclosure. Note where the power and transformer leads connect on the underside of the board so that you can wire in the transformers after the circuit board is installed in the enclosure.
<strong>Step 5</strong> Mount the remaining parts: the volume control, audio cable, USB charging cable, neon light and on/off switch. <strong>Step 6</strong> Finish wiring. Solder the transformer leads, and wire the AC power. <strong>Step 7</strong> Install the tubes. Support the board from below as you wiggle the tubes in place.

Mounting Components

Step 5 Mount the remaining parts: the volume control, audio cable, USB charging cable, neon light and on/off switch. Step 6 Finish wiring. Solder the transformer leads, and wire the AC power. Step 7 Install the tubes. Support the board from below as you wiggle the tubes in place.
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