Product Review - Aragon 8008x3 Three-Channel Power Amplifier - June, 1999
8008x3 Three Channel Power Amplifier
Rated Power: 200 watts/channel @8 ohms, all channels driven, 400 watts/channel @4 ohms, all channels driven.
FR: 5 Hz - 20 kHz (Flat)
THD: < 0.05%
Size: 8"H x 19"W x 15 1/2"D
Weight: 68 Pounds
MSRP: $2,499 USA
Mondial Designs Ltd., 20 Livingstone Avenue, Dobbs Ferry, New York 10522; Phone 914-693-8008; Fax 914-693-7199; E-Mail [email protected]; Web http://www.mondialdesigns.com.
"Dont get crazy," said Paul at Mondial. I had just asked whether or not somebody, implying myself, could supplement the already hefty power supply of the 8008x3 by connecting additional storage capacitors in parallel. After all, even though 96,000 µF (micro Farads) is a heap for three channels, gosh darn it, theres a little space left inside! Paul then assured me that, coupled with the large 2,000VA transformer, the abilities of the power supply would easily accommodate three channels. Also, since the additional capacitors would affect the output impedance of the supply that the rest of the amp was designed around, Id be best off leaving things as there were. He also pointed out, the single power supply could direct all of its efforts into a single channel if need be, a feature my dual-mono BB version didnt offer. Okay, okay. Ill leave it alone.
The amplifier chassis is essentially a heavy gauge black box with a nicely finished, thick faceplate. Three amplifier modules mount to heat sinks on the sides and rear. The sturdy unbalanced RCA style inputs correspond to the same number of outputs, and standard gold-plated binding posts accept banana plugs, spades, or bare wire. The power cord is detachable.
Only after my daughter Maggie demonstrated the powerfully rugged styling of the amplifier, pointing out its finer aesthetic values, was I allowed to remove the top so that I could take a look inside. The power supply sits in the middle, a hub of the three modules, occupying the majority of the internal volume. The layout is simple and neat. Good job with the wire ties guys.
I measured the DC rails, very carefully, as +/- 77 volts (with a 121 volt rms AC main.) This is substantially higher than an amplifier needs to spec 200 watts at eight Ohms, but not excessively so. 200 watts/channel on an eight Ohm load equates to 40 volts RMS, requiring a theoretical DC rail voltage of about 57 volts (peak voltage based on 40 volts rms is calculated by multiplying 40 by the square root of 2.)
This carries two implications. One, because the power supply isnt regulated, the rail voltage available to the output stage will be limited only by the filter capacitance, the transformer, and the wall socket. I include the wall socket because, yes, the big boys will draw enough juice under extreme circumstances to tax the AC line. Ive watched the meter measuring a residential AC wall socket drop from 120 volts to 105 volts in a particular occasion when an amplifier equipped with an 1,800 VA transformer went head first into a load that took a healthy dip to 1.6 Ohms. Since 8 Ohm loads pull relatively little current, the output capabilities of the 8008x3 will far exceed the 200 watt/channel rating into eight Ohms, possibly on the order of 300 watts, even if the main rails drop to 70 volts due to the aforementioned. So its conservatively rated at eight Ohms to say the least.
Secondly, take into consideration that the impedance of a power supply will inevitably cause any rail voltage to sag when the circuit drives at higher output levels, either due to higher signal levels or a lower impedance load. The greater the VA capability of the transformer, and the greater the step-down ratio (and hence lower rail voltage), the less it will likely happen, but it will eventually happen. Because of this, no amp that Im aware of truly "doubles down," as the impedance halves (i.e., 200 watts at 8 Ohms, 400 watts at 4 Ohms, 800 watts at 2 Ohms). Every amplifier I've run into that claims this simply reduces the published power specs at 8 Ohms. Such is the case with the 8008x3. That said, so long as the wall socket itself holds up, the rail voltage will remain sufficient to maintain the promised 40 volts rms into almost any single load short of a stray hair pin. What does a 2000VA transformer with moderately high 77 volt rails mean? Everybody say it at once, "THAT MEANS CURRENT!" At least 30 amps to go around, continuously. Im not referring to that useless peak to peak nonsense. This means real, unflinching power. Ribbons? ESLs? Step up to the plate.
The single power supply of the 8008x3 feeds all three channels, as opposed to a triple-monaural configuration with dedicated power supplies for each channel. The reasoning behind this is that a single power supply can better serve the fluctuating demands between channels. Mondial alludes to this fact, pointing out that stereo may benefit from increased channel separation, but separate power supplies do not provide significant separation of the audio between channels. Power demands between stereo channels remain pretty much equal, contrasting situations, such as home theater, where a center channel is used. Although I think the 8008x3 functions very well in stereo, if ultimate channel separation were an issue, one could certainly put the amp on center/rear duty. Then let either a dual-mono amp, or a pair of monoblocks, take care of the front left and right, maintaining ideal separation across the front soundstage. True, there might be theoretical cross-talk between the rear and center, but at that point, who cares? If you do, get five monoblocks, but expect to pay through the nose for similar drive capability. If youre willing to drop a ton of green paper or plastic on the counter, Aragon has five fully balanced, class A biased, Palladium II mono amplifiers, each easily capable of cruising at over a kilowatt into two Ohms, ready and waiting. I do like the idea, but at $12,500 for a matching set . . . .
The standard 8008x3 uses the same modular gain stages as the 8008BB, sharing the same 10 kHz square wave response and bandwidth characteristics. With an upper -3 dB limit of 500 kHz, few can challenge the "speed" of this amplifier, except rare drag racers such as Spectral or Goldmund, who get into the MegaHertz before loosening up. How relevant this is to audio frequencies is questionable, but its safe to say that when it comes to bandwidth or phase response, the amplifier is far from the weakest link in any chain. In addition, the gradual taper of high-frequency response, and lack of ringing in the square wave, indicates very good phase stability. At least its not going to oscillate into a reactive load and blow up because some trendy CD player leaks RF into the analog outputs!
Like the 8008BB, the input circuit is balanced until the output stage, providing low level gain stages with excellent common mode noise rejection. However, unlike the BB version, the x3 doesnt offer balanced inputs. If, perchance, you require the benefits of balanced interconnect hookup, Mondial has recently begun shipping the 8008x3b, for another $250. Upgrades to convert the 8008x3 to the version with balanced inputs will run $350 for those interested.
Each output stage uses twelve bipolar transistors in a standard push-pull configuration. According to an article by Henry Pasternack, push-pull circuits do a bang up job of rejecting ripple in the power supply (AC components on the DC rails caused by charging and draining the filter capacitors). More filter capacitance results in less ripple, although the only way to really eliminate it is through very heavy regulation. Neither the 8008BB or 8008x3 regulate the power supply for the output stage. Power supplies with minimal draw can be regulated quite cheaply with zener diodes or a transistor or two. However, because the regulation transistors must handle as much current as the output devices themselves, this simply isnt practical with big power amps. The output stages can compensate for the varying rail voltage, and the push-pull makes it even easier.
So, after a thorough examination inside and out, I concluded that, yes, it is built well, very well. It resembles, in some ways, a piece of lab equipment. Very functional, but not very fancy-looking. Well, the faceplate itself has some exotic cosmetic appeal. On the other hand, while the cost isnt exorbitant by high-end standards, neither is it cheeseburger change. A sensible question arises when you add up the 8008BB with the 8008x3 and come up with about five grand ($4,500 if you get the ST version instead of the BB) for five channels. Why not look into a powerful, less expensive, single-chassis, 5-channel amplifier? There are plenty of good ones out there, to be sure. Take your pick. Krell, Sunfire, Parasound, Cinepro, ATI, and a few other companies build relatively compact, affordable powerhouses.
I thought about bolting the two separate amplifiers together to form a single entity with two power cords. That thought weighs 144 pounds. I cant speak for anyone else, but until I actually own a house, I dont want any audio equipment Im going to have trouble moving. I hauled a stereo Krell FPB-300 up one flight of stairs for a friend, which weighs slightly less, and almost broke something that is permanently attached to my body. At the same time, the backbone of any amplifier is the power supply, and good power supplies are heavy. For anyone who really wants a relatively small single box (100 pounds or less, for all five channels, but lots of power, for a little less money), its out there, but I couldnt honestly claim that its the same thing. Theres something to say about grace through the careful bridling of brute force. Ever look at a ballet dancers legs? Surely, a couple of medium-large 2 and 3 channel amps arent the ultimate expression of that philosophy, but theyre a prancing leap in that direction.
I began my affair with the 8008x3 in stereo. Bass pulsed like the heart beat of a large healthy mammal - solid, stout, and like most of us hope, consistently. Midrange and treble floated and pounced following the curves of program material as an excited kitten would a length of darting yarn. Not harsh, strident, overbearing, or congested like stereotypical "muscle amps," occasionally a little dry and resolved compared to more exuberant or euphonic audiophile favorites of similar caliber. Strangely enough, this trait attracted me to the Aragon family in the first place, just as Im sure it has caused others to keep browsing. In comparison, the Sunfire stereo amplifier, rated at 300 watts/channel, took a more political, appeasing stance. Smooth, warm, and easy-going, more recordings made it through the CD player driving the Sunfire without raising the hair on my neck. It may always be more inherently ear-friendly, but sometimes I like my neck hair to rise. Leonard Cohens "I Take This Waltz," and "Tower of Song" rode the Sunfires voltage source output like a luxury car - slick, almost visibly present, but definitely cozy. I tried the current source output and found the presentation leaner, in that the combination of the 1 Ohm resistor and the impedance of the speaker caused a dip in the mid-bass, and a shelving boost above 500 Hz with the Infinitys. The M&K satellites had a similar effect except that the lower mid-bass became accentuated, contributing to a fatter character. Fat, yet lean? You betcha.
Next to the Sunfires voltage source outputs, which I heavily preferred between the other hookup options available with that amplifier, the 8008x3 carried a bit more weight in the bass, presenting a slightly more convincing sense of mass and body. The 8008x3 opened the top-end open like gauze from an oozing wound (is it time for lunch yet?) While that did benefit the resolved detail, perception of airiness and ambiance, it also laid bare the ribs of the roast. Leonard sounded more recorded - the short distance to the microphone, artificial reverb, and other mixing/mastering tactics became readily apparent. Similarly, the utter lack of vocal ambient information on Tori Amos "Boys for Pele" CD, contrasted her richly open piano, hanging in the air like a thumbtack in a heel. Still enjoyable, but with the Aragon, more obviously unnatural. Is that type of accuracy desirable? I dont think it is for everyone. I certainly appreciate the characteristic, though I also enjoy dissecting sound as much as bathing in it.
While following the lead of Dolby-Digital and DTS soundtracks, the 8008x3 performed as well as I could ask. It is funny that most of the listening material we get in showrooms when it comes to 5.1 material consists of a lot of crashing, gunshots, explosions, and fist fights. While it is neat, and may prove a good test for output levels, its neither real nor familiar. The best tests for fidelity usually involve things were exposed to such as dialog, instrumental or vocal music, rain, lapping water, and even slopping mud. I watched "A Bug's Life" and "Armageddon" on DVD, and the 8008x3 did deliver the wow factor, but more importantly didn't draw attention to itself. My focus stayed on the movies, never distracted by a lack of intelligibility or distortion at the high side of dynamic range.
Regardless of how much I enjoy the 8008x3 in my own home, whether or not it will benefit any given situation depends precisely on the particulars. As far as speakers are concerned, those that demand torrents of current will benefit most from the 8008x3s power supply. The voltage swing is significant, but many amplifiers out there can swing large amounts of voltage, especially those capable of bridging channels. From my own experience with this amp in my own system and others, it mates especially well with less efficient conventional speakers, good ribbon or quasi-ribbon designs, as well as electrostatic panels, eliciting life that would otherwise lie mute. Thats not to say that more forgiving loads wont work well. The refined character will certainly benefit an amplifier-friendly loudspeaker. More forgiving loads just work well with a wider variety of amplifiers. The 8008x3 is simply oblivious to almost any impedance, although it could be argued, I suppose, that the REALLY big amplifiers, such as the monolithic Krell FPB-650M monoblocks, are more indifferent. But that in itself doesn't guarantee superior sound, it only allows it. The 8008x3 is a practical implementation based on the virtue of indifference.
Speakers that I've noticed which don't tend to fare well with Aragon amps in general (based on listening with the 8008BB and Palladium II's which share the same circuitry) tended to have crispy, slightly accentuated treble, which the top-end extension of the amplifier will in no way complement. Even though I found the amplifier itself just a little on the smooth and sweet side, if the goal is to soften the higher side of the spectrum, this is the wrong amp for the job.
As far as electronics go, the 8008x3s rather low input impedance of 22 kOhms does raise minor concern, mainly that some less expensive preamps, or receivers with pre-outs, may have difficulty driving the inputs. The possibility that the 8008x3 would meet a component of such dismal quality is unlikely, but possible, and should be mentioned. Although I don't think that the Yamaha RX-V995 used during the review brought out the ultimate potential of the entire system, it did a very good job for a $1,000 mass market receiver, and the raw drive capability of the preamp outputs had nothing to do with any shortcomings. I would have liked to have a Lexicon MC-1 available, but we make due with dealt cards.
Also, a weird feature of the amplifier makes it incompatible with directly connected passive attenuators. Because the input stages are balanced, fed by an unbalanced jack, if a substantial impedance is placed between the hot side of the input and ground, and the hot input and the hot output simultaneously, the situation causes an irritating buzz, much like a ground loop. I've noticed the same thing with Bryston 7-B monoblocks when configured for a balanced input. When the input directly connects to an active output, or a shorting plug, the electronic background falls into a dead quiet. Go figure. Thats not a real issue in a home theater situation, or even most two-channel applications. But, if you turn the amplifier on with speakers connected but no source, its going to buzz. Its not broken, it just does that, so be aware of it.
One more thing. If the above issue is addressed, the output is as quiet as any other amplifier Ive heard yet. However, the 2,000 VA transformer does generate a little mechanical noise. It's difficult to pick out under most normal circumstances, but in the middle of the night when everyone else is asleep, and traffic dies away for miles, an attentive ear can lock onto it from across the room. Not as bad as a relatively noisy cooling fan, but there. You probably know how audiophiles can be picky. Reality is that transformers hum. Big transformers hum more. Ever listen to the bionic alien step-down bees the power company uses? If that kind of thing bothers you, consider building the amplifier into a cabinet or something, but since the amplifier runs a substantial idle current, generating a good portion of heat, make sure its well ventilated, perhaps with some really loud cooling fans! Potting the transformer with some gooey compound might offer some benefit, although I dont think that it would help the warranty at all.
Overall, the 8008x3 operates with a complete lack of etiquette, and does so exceedingly well. It lets bad recordings sound just as bad as they wanna be. It wont do any favors for deficiencies in electronic performance upstream, nor "synergistically" compensate for loudspeakers. While not harsh or fatiguing in itself, this amplifier is in no way euphemistically musical, soft, warm, or pleasant. Its downright unforgiving. Not what I go looking for in a mate, but exactly what I want from an amplifier in a long-term relationship. I wouldnt say its perfect. I dont have a reference for a perfect amplifier. (One might point to live music as such. If so, one should look into how a microphone works.) What I would venture to say is that the 8008x3 is one of the few amplifiers that cannot only engage me with the overwhelming experience of well-recorded music, but show me clearly the facets of the recording itself, pleasant or not.
Bottom line: I like this amplifier. I like it a lot. Princess Maggie - my daughter (shown below) - officially approves too!
For the Record, components used during review
Aragon 8008BB Power Amplifier
Sunfire Stereo Power Amplifier
Yamaha RX-V995 Receiver
M&K THX-Select Loudspeaker System
Infinity Renaissance 90 Loudspeakers
JVC XL-Z1050 CD player
Pioneer DV-414 DVD Player
Audio Control C-101SE EQ
Bybee/Curl Prototype AC Purifiers & Power Cords
M'Dor Power Cord
DH Labs Silver Sonic Interconnects
AudioQuest Diamond Interconnects
Liberty Emerald 14-4 Speaker cable, custom terminated.
© Copyright 1999 Secrets of Home Theater & High Fidelity
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