"This minuscule pocket amp (2.5 by 1 by 0.6 inches, and just 1 ounce) has full, warm, and accurate sound quality. We were disappointed by battery life—the one triple-A lasted only 7 to 9 hours—and the music quality degraded before the power light indicated that the battery was going. For a mobile listener, though, this is the best choice."
Many thanks to PC Magarzine and Mr. Matthew D. Sarrel, PC Magazine Labs' technical director.
Note that the SuperMicro reviewed was an earlier version and the latest versions have been improved with better battery life.
Note that you need an mini-to-mini interconnect cable to use this amp (connected to the volume control side). You may add the OFC cable into your shopping cart when you buy this amp. You can buy such cable from others such as Radio Shack, but our cable is very flexible - the best for portable use. You don't need anything else and this amp is truly plug-and-play.
The following picture shows how to connect it with a Sharp MD player and a pair of ER4S headphones. From the top to the bottom: input jack, power switch, power LED, XinFeed switch, volume control buttons and output jack. For how to use the switches, see the FAQ below.
Press or hold the up button to increase volume; press or hold the down button to decrease volume. The first time you use the amp, hold the up button until you hear. The last volume position is usually remembered even after you changed battery. The best way to set volume is to leave the source volume between 1/3 and 2/3 or so and use the amp buttons for volume adjustment. If you turn the source level to too low, the S/N (signal-to-noise ratio) becomes worse.
As showing in above picture, move the slide switch to right to enable XinFeed; move to left to bypass it.
In order to set the switch, you must open the case cover. The switch is located on the output jack. Looking at above picture, push the slider down to bypass it (for HD580 etc.) or push it up (toward the input jack) to enable it (for ER4P etc.). When you use low-impedance headphones such as ER4P and Grado 60, you should enable this switch for the amp to work properly. This switch is no longer available.
Absolutely yes, even the most power-hungry AKG 1000 is no problem.
The Koss KSC-50 available from BestBuy for only $17 is THE headphone everybody should get a pair. Very portable, comfortable and affordable. They sound so good with portables that you may not even want an amp for them. If they sound too bassy to you, then drill a hole in the center of the foam pads. If you want to know what's the best sound you can hear, then get the HD580 for $130 online.
Under some conditions, you may try unplug the headphones and re-plug them. For amps with a ER4P-to-S switch, enable the switch, especially while using low-impedance headphones such as ER4P and Grado 60.
Yes. You can buy an automatic pencil from Wal-Mart, cut off its tip and glue it to this amp as showing in this picture. You should glue it to the case cover; so you can replace the cover (buy a battery case, 270-414, from Radio Shack) in case you don't want the clip later.
Yes, if the followings are your concern:
The SuperMicro amp's battery life seems short at first, especially if you have been spoiled by the super long battery life of super mini. But remember, now you only need a single AAA battery. With just one more AAA in your pocket as a backup (you needed three before), your music never stop!
The following pictures show tested noise level for Micro (top) and Mini (bottom). Both amps are set to the highest volume (both have gain 11), open input (not shorted) and 100 ohm load at output. As you see, the switching circuit used in Micro to boost voltage adds no extra noise.
Copyright © 2005
Xin Feng Company