|Fringe with Greg Smith
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Computer-Sound Antacid from AMC
It was September of 1986, and I wanted a new computer bad. The Apple IIgs hit the stores, and it had everything I wanted: a fancy new 16-bit processor, compatibility with all the Apple II software I'd bought and written myself in the previous few years, and enhanced graphics and sound. (The "gs" designation certainly wasn't in my honor.) The Ensoniq wavetable sound was certainly a big selling point, and all the store demos coupled the computer with a set of powered Bose speakers that I think were around $250 per pair. I wanted a set of those pretty bad too. Lucky for me, my father knew better. What I got instead was an old solid-state Marantz receiver (left over from his last upgrade) and a little set of EPI speakers. That combination kicked butt. The lesson I learned from this experience continues to hold true today: Audio systems with little powered speakers aimed strictly at computer use usually stink, both from a performance and value standpoint. Sure, the dirt-cheap stuff from Labtec is decent for your dollar, and you can get some nice systems from Cambridge Soundworks, but the majority of "computer speakers" make me sick to my stomach. What's an audiophile to do? The last two months I've been solving this problem quite nicely by using an inexpensive integrated amplifier. The AMC 3020 offers a compact, moderately powerful amplifier with a couple of features that make it particularly well-suited for computer use. But it's no slouch in a more traditional audio system either. Mating the amp with a CD player like AMC's CD9 and some budget speakers makes for quite a musical setup at little more than a rack-system price.
I don't know what AMC stands for, but I can tell you a bit about the company. As is typical for international companies nowadays, it's a bit complicated to follow AMC's products around the world. The company's manufacturing facilities are in Taiwan, but the main design work is done in Los Angeles in cooperation with Weltronics, who also happen to be AMC's US distributor. There's an office in London involved in the whole process as well, but I got lost before I figured out what they did. The important part is that you can buy AMC products all over the world; I counted 35 countries on their home page.
From the front, the AMC 3020 looks like your run-of-the-mill integrated amp. You get the usual balance, bass, and treble controls with a nice center stop for each. The big volume-control knob has a decent feel considering the 3020's modest $279 price tag. There's a selector for using the tape loop and a choice of five inputs (the "phono/aux" jack does not feature a phono preamp; it's a regular line-level input). Wait, what's this? "Mix"? Does this tune into one of those boring "Best mix of the [insert decade here]" radio stations? Nope. When you switch to that position, the 3020 turns into a mini five-channel mixing board. All the inputs play at once, and there are small volume controls for adjusting the relative levels of the inputs on the back.
This is the key to the multimedia applications for this component. While many people listen to music CDs on their computer, using either headphones or speakers, doing so requires that you have a free CD-ROM drive available. Worse, as an uncontrollable programmer, I'm constantly rebooting my computer. This stops any computer CD I was listening to dead, leaving uncomfortable silence right during the time I'd like to be comforted by some music. Those of you who frequently fight battles against General Protection Fault and his army of minions have a similar experience. For all these reasons, and to get better sound, I usually have a separate CD player connected to the amplifier my computer feeds.
But what you lose out on with this configuration is the sound your computer is making. While I'm not so distressed that I can't hear the beep and chirps that go along with the daily error messages I receive, when I switch to playing games I'm kind of stuck. Even the best game soundtrack gets kind of monotonous after you've been playing something for dozens of hours. It used to be fairly straightforward to start a game, switch to an audio CD in your CD-ROM drive, and combine the soundtrack with some other music. But today's data-laden programs can't run without the game CD-ROM stuck firmly in the drive. When I'm battling smugglers in HardWar, I like to have appropriately soothing music in the background -- like Metallica. (Ride the Lightening goes particularly well with space flight, I've always thought). With a traditional preamp, I'm stuck with either hearing the game (absolutely a necessity for many modern titles) or listening to my CD player. Using the AMC 3020, I can mix the two together seamlessly. The volume differences between sources can easily be adjusted either with the computer's control panel or with the potentiometers on the back of the 3020.
Sure, it's a cool feature, but it's not worth having unless the amp is nice to listen to. The 3020 sounds far better than you'd expect for a $279. Driving the Audes 105 speakers I looked at last month, the amplifier section sounded clean and powerful, and it didn't exhibit any of the glaring treble that plagues mass-market receivers in this price range. It seems kind of cliché'd to talk about how a small amplifier sounds more powerful than you'd expect, but the specs for the AMC 3020 back that up. Nominally rated at 20Wpc, the peak power at clipping is a more beefy 33W. Even better, the peak power into 4 ohms is 42W. While it's not quite a power-doubling monster like some more serious amplifiers (where there's twice as much wattage at 4 ohms as there is at 8), this increase of power into lower-impedance loads bodes well for the 3020's ability to drive real-world speakers. A typical $279 receiver will come with stickers issuing grave warnings against using anything lower than an 8-ohm speaker. In comparison, AMC's literature claims that the 3020 is capable of +/-17A into a 1-ohm load!
With that encouragement, I decided to give the 3020 a more serious workout. I unboxed my Magnepan MMG speakers in my office, where they don't quite fit. The 10'x10' space isn't really the right kind of environment for them, but they still sound rather nice if I move to the other end of the room. Driving the 4-ohm, inefficient Magnepans to a reasonable volume level is a task few amplifiers at the 3020's price are capable of. At any volume level, this AMC didn't really give commendable control over the bass part of the panels, but that's to be expected. In my experience, those don't really come alive until you've got at least 50W driving them. But other than that, there was little my more expensive amplifiers do that the AMC isn't competitive with. Sure, there's compression as the volume goes up, and the 3020 clips well before these speakers start to sound loud (even in this small room). But the overall balance was excellent.
I used the Magnepan speakers with the AMC amp for over a month without incident. This apparently made me a bit too relaxed. One Sunday when I was working late and no one was around, I was cranking up the Eric Woolfson/Alan Parsons rock musical Freudiana [EMI CDP 79 5415 2] to volumes well into the amp's clipping area. After about half an hour of this cruel abuse, the amp finally gave up. Out of nowhere, a crackling noise started. Yes, I'd blown something up, probably an output transistor or two. While I don't want to totally dismiss it, you should factor in that I was using a speaker far more difficult to drive than most 3020 users will ever connect, and I'm merciless when it comes to pounding power amps. Sure, my sadistic rituals were a bit too much for the amp to handle, but to be honest I was amazed it had lasted as long as it did. The 3020 is not a totally bulletproof powerhouse, but it goes well beyond my expectations for an integrated amp at its price.
Using the two different pairs of speakers, I got more than acceptable results. Switching to the other side, I decided to see what the source side of the equation revealed. AMC's CD9 retails for $299, making it one of the more affordable units on the market with a coaxial digital output. Recently I've been seeing street prices as low as $200 for this player, which makes it even a better value. You'd think that these two AMC components would be designed to work well together; add a decent set of $200 speakers that will run with a modest amount of power, and you're off and running with a whole system for under $700. I compared the CD9 with a CEC 2100 CD player (full review in the works). That unit's $399 retail price and coax output make it similar in several respects to the AMC player, but the sound was quite different. I used two pairs of 3' Belden 89259 cables with Radio Shack gold RCA plugs to connect the players, per my Fringe column on DIY interconnects.
Using my recent review favorite, Dead Can Dance's Into the Labyrinth [Warner Bros. 9 45384-2], I found the AMC CD9 to give unexpected deep and controlled bass. The CEC player seemed a bit warmer on the bottom-end in comparison, making the bass seem not quite as tight. But it more than made up for it with a much improved sense of the recording space. The tinkling bells and other percussion were clearly better on the CEC 2100; it's the obvious champ in terms of recorded detail. The cool, laid-back CD9 output made "Come to My Aid" from Simply Red's Picture Book [Elektra E2-60452] sound more like the work of a smooth jazz band. Meanwhile, the more aggressive CEC 2100 moved the synthesizer and guitar parts forward a bit, emphasizing the band's rock side.
The forgiving CD9 DAC section will mate well with a system that already tends toward being overly bright, which makes it a good match for many inexpensive systems. Its coaxial digital output suggests use as an inexpensive transport as well, but that's where I found the player performed below my expectations. With the Pierre Verany test suite, the 1mm defect of track 31 was handled with ease, but the 1.25mm hole on track 32 caused frequent skipping. Even worse, the CD9 wasn't able to track even the 0.375mm defect on track 2 of CD Check. Proving this isn't just a test-bench issue, the AMC player didn't do very well on my torture test set of scratched music CDs I keep around either. If error correction is an important concern for you, the AMC CD9 is probably not the transport you want. Where the CD9 gets back some points is in the area of build quality. The tray mechanism and buttons feel quite solid for a player in this price range. Sure, it's all plastic, but at least it's not super-cheap, thin plastic.
If the CD9 is solid, the AMC 3020 is downright sturdy. It weighs in at 11 pounds, a substantial power transformer connecting to a clean-looking circuit board. There are real speaker binding posts on the back; the spade connectors on the home-terminated AudioQuest Type 4 I used slid right in and held firmly. Yes, the posts have plastic parts, but they seem to work quite well.
Less impressive are the run-of-the-mill jumpers you'll find on the back panel. The 3020 features separate preamp and power-amp sections that you can utilize separately. As with most inexpensive integrated setups, these are connected together externally with U-shaped metal bars. I found that replacing those bars with a good set of interconnects gave a very worthwhile improvement in the 3020's sound. I cued Dead Can Dance again, this time "The Ubiquitous Mr. Lovegrove." Grabbing some of the DIY designs I mentioned a few months ago, the Copper Signal Tape with Radio Shack gold connectors gave a different balance on the top end compared to the factory jumpers. It was more detailed, but a bit rougher in some respects. The big win was getting considerably more deep bass. Switching instead to Belden 89259-based cable gave me more what I was looking for. The treble was smooth yet detailed, easily besting either of the other methods of connecting the amplifier's two sections. The fact that the Signal Tape interconnects do a little better on the really low-end notes doesn't really matter when we're talking about a relatively low-powered amp and inexpensive speakers. You can get a free sample of the Belden cable that's long enough to make some little jumpers and have enough left over to make a short set of interconnects, so I highly recommend that AMC 3020 owners consider this upgrade. Anybody with an integrated amp using the usual metal bars to connect its sections should investigate using short cables instead.
While I'm suggesting performance tune-ups, one old-time tweak takes on a particularly valid application with the 3020. One way to improve just about any preamp is to make shorting plugs for the inputs you're not using. Pick up some cheap RCA connectors and wire together the two pins you'd normally connect wires to. Place these shorting plugs in the place of any input jack you're not using; they can help reduce the amount of noise the unused sections pick up when they're a floating ground. With the AMC 3020, this takes on a new importance. Instead of just producing stray noise, the extra inputs can be actively mixed into the music. Making sure they're as quiet as possible can't help but improve how the amp sounds.
The mix feature enables all kinds of other tricks I didn't think of until I'd used the 3020 for a while. Like most preamps, the 3020 gets a bit unbalanced when the volume control is at a very low setting. While this wasn't an issue with the Magnepans, I found it difficult to play the more sensitive Audes speakers during the day at work. When I turned down the volume enough that I wasn't disturbing the rest of the office, I was into the range of the potentiometer where it doesn't track left and right equally. With a normal preamp, there's nothing you can about this. With the 3020, I suddenly found myself with a new option. By switching the input source to "mix," I could attenuate the CD player input signal a bit using the control on the back of the amp. Then the front-panel volume could be turned up louder, getting out of the non-linear part at the bottom of its range. Quite a handy solution to a very common problem.
Similarly, I found the mixer controls handy for comparing components. The AMC CD9 has a higher output voltage than the CEC 2100, which meant the AMC player always sounded better when I compared the two directly -- at first. By switching to "mix" and attenuating the CD9, I was able to use a voltmeter to match the two players' volumes almost perfectly. It certainly made for a fairer comparison.
AMC's budget-priced equipment makes for a quite nice little system. With careful attention paid to cabling and speaker matching, the CD9/3020 combination far exceeded my expectations for what a budget system in this price range was capable of. While the CD9's tracking issues prevent me from recommending it too strongly, the 3020 was flawless while I had it here (right until I blew it up, that is). When you consider all of the features this integrated amp has, including use as both a preamp and a power amp, the mix capability and tone controls, the retail price would be a bargain even if the unit was otherwise mediocre. The excellent sound quality makes it a no-brainer. I suspect that you can probably find an integrated amp around this price that might sound a little bit better or be slightly more powerful. But I highly doubt that that piece would even come close to including all the goodies that the 3020 has. If you can't find a local dealer, AMC products are available with hefty discounts from mail-order companies like Audio Advisor and Sound City. While I've had some trouble in the past with availability when buying from Sound City, they have an interesting special running now that is fully authorized by Weltronics. The combination of AMC's 1100 preamp, which has the same basic features as the 3020 but without any power, is bundled with the AMC 2100 power amp, delivering 100Wpc, at a considerable savings.
As for me, I think I'm going to get an Apple II emulator running and mix together a game of Autoduel with one of those Rock of the 80s discs. Next stop 1986, but with much better sound this time around!
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