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Aragon 2004 MK II Review (Vintage Amplifier)

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 49 32.2%
  • 2. Not terrible (postman panther)

    Votes: 74 48.7%
  • 3. Fine (happy panther)

    Votes: 20 13.2%
  • 4. Great (golfing panther)

    Votes: 9 5.9%

  • Total voters
    152

respice finem

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Not bad for its age IMHO. A teardown would be interesting, the noise is somewhat like in a class D amp, and that's hardly to expect from a 1990 amp.
 

linesplice

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Fascinating. I remember looking at one of these back in the day and thinking I'd "upgrade" to it based on how much the "reviewers" were JIMPing about it. I wonder if similar era Krell, Levinson, Adcom, Sunfire, etc., amps would also actually test poorly. Could compare some of the tests against what Stereophile had at the time, but as noted, things like caps can degrade over all those years.
 

Putter

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Sobering review for all the vintage amp hoarders out there who are too cheap to get recaps done (me)
I'd still be willing to bet that it would be indistinguishable from a new amp with similar specs that match the aragon when new.
 

sarumbear

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tmtomh

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I voted Not Terrible.

We don't know if the measured noise is part of the design or due to age. The fact that it rises with signal strength suggests the noise is worse than the as-new performance level. On the other hand, the measured signal to noise ratio is sufficiently high with this unit as-is that I question how much the noise performance would improve if it were refurbished.

So for me the noise, while a key issue, is a push as far as voting goes, since we just don't know.

The reason I voted Not Terrible, aka the second-worst option, is because that crosstalk performance is just dire. Yuk.
 

sam_adams

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There's some pics of the insides of the 4004 and links to some documentation in this AK discussion.

A pic from the brochure linked upthread:

Brochure_A_3_Top.jpg


Claimed A-weighted SNR at full rated power: 120 dB.
 
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pma

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The fact that it rises with signal strength suggests the noise is worse than the as-new performance level.

Well, it does not rise much, in fact. Please look at the plots carefully. In the @amirm 5W/4ohm measurement, the noise floor is at -140 to -150dBr and the mains spuriae attack just below -90dBr. However, in his "noise measurement", the noise floor is at -130dBr (10-20dB higher) and mains spuriae are just above -100dBr. Why that big rise of the noise floor without input signal? Because there is a mistake in methodology. As @amirm replied to my question,
he just turned off the generator:
Yes. That is a quick grab of the dashboard which is always at 5 watts into 4 ohm load with the generator turned off.

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.
 

P_M

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who are the 2 people gave "Great" vote to this ?
 

tmtomh

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Well, it does not rise much, in fact. Please look at the plots carefully. In the @amirm 5W/4ohm measurement, the noise floor is at -140 to -150dBr and the mains spuriae attack just below -90dBr. However, in his "noise measurement", the noise floor is at -130dBr (10-20dB higher) and mains spuriae are just above -100dBr. Why that big rise of the noise floor without input signal? Because there is a mistake in methodology. As @amirm replied to my question,
he just turned off the generator:


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.

@amirm is this right?
 

phoenixdogfan

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There's some pics of the insides of the 4004 and links to some documentation in this AK discussion.

A pic from the brochure linked upthread:

View attachment 174094

Claimed A-weighted SNR at full rated power: 120 dB.
Aragon lists its THD spec as .06% which translates into a 64 db SINAD, so maybe Amir's measure of 65-66 db SINAD is really consistent with original design specs?
 

HiFidFan

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I find it impossible to assign a "panther rating" to this. In absence of any information regarding individual components being in or out of spec of a 30 year old dusty amp, I don't understand the utility, or point, to a review like this.
 
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Mosfet

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I owned an Acurus A150, an Acurus A250 and an Aragon 4004 MKII. That was back in my naive, subjectivist days.
 

respice finem

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If you are not then why are you posting detailed engineering comments? :facepalm:
In the same "logic", you must be a physician to describe a skin rash when you see one? Or a designer to describe what you see or don't see in a given design, even in detail? If it were this way, this would be a very small (and IMHO boring) forum ;)
I saw it this way, which could be wrong, as any opinion.
 
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sarumbear

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In the same "logic", you must be a physician to describe a skin rash when you see one? Or a designer to describe what you see or don't see in a given design, even in detail? If it were this way, this would be a very small (and IMHO boring) forum ;)
I saw it this way, which could be wrong, as any opinion.
Fair enough
 

RayDunzl

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I owned an Acurus A150, an Acurus A250 and an Aragon 4004 MKII. That was back in my naive, subjectivist days.

I have an A250.

Maybe I'll drag it out and measure it.
 
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