HeadRoom Headphone Amplifier & Digital-Analog Converter Micro Amp Panel Descriptions

The Micro Amp

Packing HeadRoom’s mobile electronics module, two nine-volt batteries, and all the knobs and switches you need into an all but bullet proof aluminum enclosure is pushing it a bit, but you won’t care because your head will be thanking you for the lovely tunes.

				5.
1.		3.		Volume
				Control
Line		Crossfeed
					6.
Input	2.	Switch
				4.	Power
Headphone				Gain	Source
	Out		Switch		Switch

7.

External Power Input

	8.
2	Thumb Screws

The Micro Amp Panel Descriptions

Front Panel

1.Line Input The line input is where you plug in the source. Preferably the Micro DAC; but it could be the line out of your iRiver or the headphone out of an iPod. You will need a mini-to-mini cable to hook up your Micro Amp.

2.Headphone Out The headphone out is where you plug in your headphones. There isn’t room for a full sized jack, but this 1/8th inch mini-plug will take the small plug of all 1/8” headphone jacks. We also sell a short flexible Grado 1/4”-1/8” adaptor for your big cans; and you can get a replacable Cardas headphone cable with a mini connector for many types of headphones, call us or consult our website for details.

3.Crossfeed Switch This switch engages the crossfeed circuit. The audio image on headphones is often not very good; typically the image is a blob on the left, a blob on the right, and a blob in the middle. The HeadRoom crossfeed provides the natural acoustic cross-feed normally heard at the left and right ear as heard from the left and right speaker. Adding back the normally occurring cross-feed signal gives your brain enough information to build the stable and natural audio image needed to have a quality listening experience. See pg.8 for more info on the HeadRoom crossfeed.

4.Gain Switch The 3-position Gain Switch accomodates various headphones’ power needs. For instance, the Low Gain setting would be used for in-ear monitors, allowing a larger range on the volume control pot. Experiementing with your headphones and the gain switch may help you to determine which setting you prefer. If have any questions regarding your headphones, feel free to call and ask us.

5.Volume Control You never know where the volume control should be set as different headphones often have widely different impedances and efficiencies, so use your ears to choose your listening level, not the level on the dial. (We recommend you choose a moderate level so as not to blow out your ears.) You also need to turn the amp OFF or ALL THE WAY DOWN before plugging in or unplugging your headphones to avoid short-circuiting the amp. As you turn the volume control knob clockwise, the volume increases.

6.Power Source Switch Immediately to the right of the volume control is the power source switch. It will run on either the two internal 9-Volt batteries or an external power supply. If the batteries are in and external supply is attached, the only way you can turn it off is by selecting ‘external’ and then unplugging the connector. We offer two power supplies: the less expensive, lovingly known as “brick”, power supply comes with the amp, the more expensive Desktop Power Supply will give you cleaner juice, and therefore cleaner, more dynamic sound.

Rear Panel

7.External Power Input Connect either your brick or Desktop Power Supply here.

8.Thumb Screws To change your batteries, unscrew the screws and remove the rear panel. Orientation of 2 nine-volt batteries is indicated by the illustrations on

the rear panel. 3