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Aragon 2004 MK II Review (Vintage Amplifier)

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 50 31.8%
  • 2. Not terrible (postman panther)

    Votes: 76 48.4%
  • 3. Fine (happy panther)

    Votes: 20 12.7%
  • 4. Great (golfing panther)

    Votes: 11 7.0%

  • Total voters
    157

AudioTodd

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I still have my 4004 MKII, but I don’t think it’s been plugged in since 2004 and it was probably only used a total of 4-5 years between its purchase in 1994 and it being retired. It resides in its original packaging but I took it out of its storage place as I’d like to revisit it and see if I can actually hear the differences I used to think I could hear. I’ve been wondering about those caps, though…

And the very insistent opinions on both sides of the debate about them aging. Some claim it is a audiofoolery but I do know people who have had big problems fixed with new caps.

Back in the day, it was a “go-to” for difficult to drive speakers with very low impedance dips like my couple pairs of Martin-Logans without paying the full Krell, et al freight. I was certain I could hear it clean up my Aerius speakers when it replaced my Hafler DH220. I was certain it was from the enormous current delivery ability rather than any “magic” because I think the high frequency impedance dipped to less than 2 ohms IIRC.

Can’t say I was ever certain I could hear improvement when the Aragon was replaced with Clayton Audio M70 Class A monoblocks driving my ReQuest speakers - at least that wouldn’t show up in measurements, including those affecting amp/speaker interactions.
 

Remlab

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Jaimo

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High voltage electrolytic capacitors simply do not last 30 years… In industrial applications, (AC variable frequency drives) the preventative maintenance recommendation for capacitor replacement is around five years. Given the heat generated by class A/B amplifiers, it is not unreasonable to see capacitor performance deteriorate. Replacing the psu caps in an amp of this vintage is a must.

This does not explain the HF noise however so this suggests that there is more than the power supply caps that require replacement.

I would really like to get my hands on an amp like this to analyze the measurable effects of component degradation.
 

jcarys

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Now I'd like to see how one of the highly reviewed Bryston amps would measure. Something like the 4B or 4BST. I see lots of them around used and have been tempted, but always consider how it would compare to something modern that is well engineered. Thanks for the review, Amir.
 

tjf

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a bit of history of Aragon electronics, and it's genesis as "Mondial Designs" -- copied from a post on the Klipsch Forums:

"Courtesy of the home theater / hifi website, we have:
Acurus was founded in 1992 as the value brand of Mondial Designs. Mondial was started with the Aragon brand, well know for its high end electronics in audiophile circles. Mondial was founded in 1986 by Paul Rosenberg and Anthony Federici, the latter of whom has since left the business. In December of 2000 Mondial was bought out by Klipsch of speaker fame. Paul Rosenberg is still with Mondial as the Director of Marketing and New Product Development.
The initial Aragon products were actually designed by Dan D'Agostino of Krell. About 11 years ago, Mike Kusiak joined Mondial as Chief Designer and is responsible for all products since, including the DIA150. All Mondial amplifiers have the same design philosophy, i.e., no integrated circuits, motorized volume pots, glass-epoxy circuit boards, large transformers, lots of capacitance and bipolar output devices.

Also, check out the review of the Acurus DIA150 at http://www.hometheaterhifi.com/volume_8_3/acurus-dia-150-integrated-amplifier-7-2001.html"

From my own memory -- As I was in the high end audio business back in the 80's and 90's -- Mondial came about as the brainchild of "Tony" Federici, who had been importing an Italian speaker line into the U.S. -- "ESB", and started Mondial as a marketing company -- he having had many contacts amongst the east coast major Hi End dealers of the 80's (Lyric in NYC, Sound Components in FL, etc.) as a Mfgrs. "Rep" and started Aragon with the assitance of Dan D' Agostino of Krell fame doing the electronics designs as a sub-contractor with Mondial.

(The name "Mondial" chosen for it's association with Ferrari and all things Italian, hence the importation of the Italian ESB speakers -- these being a visual copy of the very popular ADS large cabinet speaker designs)

Anyway, I'm not sure of which OEM mfgr. was making the Aragon amps at the time, but as we move into the early 90's, Mondial starts it's less expensive "Acurus" electronics line, made in So. Calif. by ATI (yes, that ATI -- who in the 70's and early 80's were known as "S.A.E" electronics -- owned by Morris Kessler -- I think Acurus is still made by ATI for Klipsch)

And so with Aragon at the "High end" and Acurus as the "Value" line, they continued on into the late 90's -- with some popularity for their "DIA" series of integrated amps, and later a CD player, and much later AV Processors for the beginning of the Home Theater craze that began to take over in the 90's. And today, Acurus still exists as a sub brand of Klipsch.

History lesson concluded -- any updates or corrections are welcome.
 

EJ3

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What specifications that I could find from the original owners manual:
1640220841393.png
 

restorer-john

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He turned off the generator which resulted in undefined high generator output impedance seen by the amp input. Thus the rise of noise floor in the "no signal" measurement. The input had to be shorted or closed by a defined impedance, like 50 ohm or 600 ohm, instead. As such is now, the "no signal" noise measurement is pointless.

Does the APX-555 not short the analogue outputs when the gen is turned off? Or is there a separate on/off/gnd toggle in the software?
 
OP
amirm

amirm

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@amirm is this right?
No. The purpose of that test was to see if the high levels of power supply noise I saw were also there when nothing was playing and that was the case. I also used that graph to minimize mains leakage but strangely, that made the dashboard look worse so I undid that. This is why the noise floor doesn't match in the two measurements.
 

sejarzo

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I heard them early 90's. They were nicknamed "the poor man’s Krell".

I owned an Acurus A150, which I guess would be "the even poorer man's Krell" as it was the budget line from Acurus.

It ran quite hot, too, just as I had read in the hifi mags about the Aragon amps, so that didn't concern me.
 
Last edited:

H-713

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I'd put this somewhere between "happy" and "postman". It's acceptable - the distortion is around my 0.05% threshold of being a concern. In a nutshell, it's got adequate (if a little unimpressive) distortion performance, quite a bit of power and in a neat-looking enclosure.
 

H-713

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High voltage electrolytic capacitors simply do not last 30 years… In industrial applications, (AC variable frequency drives) the preventative maintenance recommendation for capacitor replacement is around five years. Given the heat generated by class A/B amplifiers, it is not unreasonable to see capacitor performance deteriorate. Replacing the psu caps in an amp of this vintage is a must.

This does not explain the HF noise however so this suggests that there is more than the power supply caps that require replacement.

I would really like to get my hands on an amp like this to analyze the measurable effects of component degradation.
Amps like this generally aren't very hard on caps. The average ripple currents are low. Internal temps on most amps are pretty reasonable, and the filter caps usually aren't right next up against the main heatsink. Most don't run 24/7/365. In fact, I've seen a lot of amps of this vintage that show no evidence of PSU capacitor degradation even after extensive use. This amp uses giant can capacitors, which are both expensive and generally have a good lifespan.

Motor drives are much, much harder on caps than a typical class AB amplifier.
 

mctron

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I'd put this somewhere between "happy" and "postman". It's acceptable - the distortion is around my 0.05% threshold of being a concern. In a nutshell, it's got adequate (if a little unimpressive) distortion performance, quite a bit of power and in a neat-looking enclosure.
What if it cost $700+ (as one just went on eBay for)?
 

H-713

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Now I'd like to see how one of the highly reviewed Bryston amps would measure. Something like the 4B or 4BST. I see lots of them around used and have been tempted, but always consider how it would compare to something modern that is well engineered. Thanks for the review, Amir.
Would be interesting - but Bryston typically uses a fairly good, fairly low distortion design. Most of them are rated at 0.01% from 20 Hz to 20 kHz, and I would expect it to be quite a bit better at 1 kHz than at 20 kHz. I feel like I measured a 4B at some point, and I want to say it measured similar to an MC650, (so about 0.005% THD at 1 kHz), but I don't remember the exact numbers. I do remember thinking that the distortion and noise was low enough not to matter.

The things also pretty much run forever, and Bryston is very good about service, so I wouldn't hesitate to purchase a used one if you found a good deal.
 

H-713

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What if it cost $700+ (as one just went on eBay for)?
I still don't take real issue. I think $700 is a little steep for one of these, but it has a neat look and is built like a tank. Schematics are available, and these should be quite reliable and easy to maintain, even at their current age. Output devices look like they're MJ15003 and MJ15004 (old, slow, bulletproof TO3 devices).

It sucks if all you look at is SINAD / Dollar, but there are other things I look for in a power amp as well.
 

EJ3

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Amps like this generally aren't very hard on caps. The average ripple currents are low. Internal temps on most amps are pretty reasonable, and the filter caps usually aren't right next up against the main heatsink. Most don't run 24/7/365. In fact, I've seen a lot of amps of this vintage that show no evidence of PSU capacitor degradation even after extensive use. This amp uses giant can capacitors, which are both expensive and generally have a good lifespan.

Motor drives are much, much harder on caps than a typical class AB amplifier.
However: These particular amps run quite warm, if not down right hot. Time x heat hurts things. (& if the unit was not in use, was it stored in an attic in a house in the Mojave desert or in the basement of a house in Nova Scotia)? With no way of knowing, if I had one, I would change & modernize all of the things that I could without affecting the circuit design.
 

tmtomh

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It would be foolish to claim at this point that Class D amps will last for 40 years - they might last that long, but we don't know.

That said, the advantage of ease of servicing/repairing/replacing components on older amps is partially undermined if those amps need to be serviced because they run hot and stress their internal components. Today's cars can't be repaired like old ones from the pre-computer age can - but today's cars are also more reliable in most respects, for example they don't need their oil changed nearly as frequently.

Also, while it's great from an environmental point of view to keep older amps in use and not discard them, if they have a performance ceiling that's inferior to today's amps and that performance gap is important to you, then no amount of servicing or maintenance is going to solve that problem.
 

Walter

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If anyone knows what it sold for originally please, post.
I don't remember for certain if it was the MK II, although I think it was, but I remember it was $1400 (well, $1395 or $1399 or something like that). I only remember because the funky notched design was very appealing to my younger self (but in the end I decided the money was better spent on "whiskey, women, and wine" than on something that would have just encouraged me to stay home alone more).
 

EJ3

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for example they don't need their oil changed nearly as frequently.
As a mechanic for well over 40 years, using oil analysis to do oil changes, the 3000 mile oil change was a myth (unless you had a VW Beetle that did not have any oil filter from the factory & was air-cooled, therefore running hotter or only drove on dirt roads & off-road). Since synthetics arrived in the early 70's (Amsoil) I have personally limited even my hotrod cars to one oil change a year (the oil analysis shows that I could go longer) but I believe that condensation due to weather changes & short run times (going to a grocery store 10-12 minutes from home, not allowing a long enough run to maintain operating temperature long enough to evaporate the condensation in the engine) would cause problems in the long run.
All my cars, (models from a 1968 Chevelle SS 396 to a 2012 Lexus [currently 30K miles], even my hot rodded Beetles (that were making 50 to 75% more power than from the factory), have gone 200K (some 300K) before needing an engine rebuild. The 3000 mile oil change was perpetrated by the oil companies & filter (oil & air) manufacturers (who enlisted the new car manufacturers to put short oil change mileage or times in the owners manual, to sell more oil & filters.
 
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