Aragon 4004 mk2 vs Adcom 555 mk2

Hey
The Macs have some global feedback, yes. That was the source of my argument. But so does most Mark Levinson and Jeff Rowland gear although they try not to say so openly; I asked them and they told me. There are many others, I am sure - especially BJT designs. I bet most bomb proof designs have NFB and I agree with Eldartford about the "negative" name being poorly suited.

I am not sold to McIntosh forever and ever (surprised? LOL!) and want to try different things to compare. This is just my 4th system but I have been financially crunched lately. I have a list of all kinds of amps once I can save some money to rotate at least one added piece. I will add the Monarchys to the list!

Going back to Eldartford's comments: I have a mathematical proof I did for one of my classes comparing local and global feedback effects and most terms drop out in equal cascaded op-amp stages to where there is no difference. However, if the stages are unequal, problems can arise - but those hifi engineers are smart people and they naturally balance the system. I admit however that the proof probably didn't cover all variables and the human ear may be able to clue in on something that was deemed mathematically "negligible" thus far in the formulation. The more I am in school, the more I realize that we actually don't know much about how the world around us works and so each one of us here may be right, or wrong. Either way, we know what each of us likes to hear and that really is the important part. The rest is pure fun in experimentation! Enjoy -

Arthur

I agree with you on design,price tag and name.. Ritteri.But that being said with the right two amplifiers you will be able to hear a difference.Whether it's for good or bad it's not that hard to hear.I suppose there's no absolutes to anything especially in this hobby.Sounds like those Pallidiums are some great amps.Aball you should try to audition some Monarchy 100 SE monoblocks on your Paradigms I guarantee the differences will not be subtle.Also Arthur do you know if the Macs use any Global feedback or just local feedback? Just curious.

Im not an engineer by any means but I kinda thought that ALL products have to have feedback of some kind. But Ive been in arguments in the past where people are telling me their products sound "superior" due to 0 feedback, and that they can "hear" the difference between amps with feedback and amps with no feedback which I kinda felt was a bit flakey. Ive always thought that what matters in the end is how good the product actually sounds regardless of design,pricetag or "brand name".

You probably have less problems with feedback phasing around one stage (local) than across the entire circuit. So in the real world, local feedback may be less problematical than global feedback, even if the net total dB is the same. In an ideal world, both would be perfect.

It is unfortunate that we use the word "Negative" to indicate polarity of the feedback. That word has negative connotations.

Yep, anything in excess is bad, feedback included. Yet, I don't understand the hang up that audiophiles have with feedback. When I say feedback, I mean GLOBAL feedback. It has a zillion advantages that any engineer can name off for you because in the rest of the electronic world, feedback is absolutely critical in just about every circuit I can think of. In audio, I don't think feedback causes any detriment to the sound per se. I have looked this up several times and the post Gmood pasted above has too many inconsistencies to be reliable IMO. Local feedback is present in 99% of amps. I talked to Nelson Pass and what he calls "zero feedback" means he has local feedback but no global. This is fine however no one ever seems to complain about local feedback sounding poor. Kind of funny that guys who buy zero feedback amps for the name are actually listening to high local feedback designs and proclaiming its benefits. An amp with no feedback at all, will crash and burn with most speakers. I guarantee it. I have seen it in the lab many many times. So, before complaining about feedback sounding bad, consider what I have said. There is probably an exception out there somewhere (meaning no NFB at all) but we probably wouldn't buy it due to audible oscillatory reactions with the speaker's reactance. Arthur

If the feedback signal were perfect with regard to gain and phase it could only improve the overall performance of the amp. High amounts of feedback become a problem when the feedback is less than perfect, either because of circuit design or real-world component tolerances. "Too much of a good thing".

Two things:

1. The feedback loop would not use a pot if the design is worth anything as the guy suggested. The switch, as a designers opinion, switches high-quality resistors in and out - doesn't use a pot so that argument is not worth reading. He is right - pots sound terrible, that is why they are rarely used or done so as to no affect the circuit.

2. The feedback switch is so that if you are using inefficient speakers, the amp will be stable with higher feedback. A zero/low feedback design can become unstable very very easily if the right (rather, wrong) conditions arise. So the switchable feedbacks are to match speakers - not correct sound. Arthur

Ritteri here's an section of an article I came across done by Doug Blackburn of Soundstage.You can go to this address and read the entire article .Of course this is one persons opinion. http://www.soundstage.com/maxdb/maxdb101998.htm

Feedback in low-level gain stages – It is becoming increasingly clear that less feedback rather than more is musically desirable. However, there is a point where you have to stop removing feedback due to some element(s) of the whole presentation falling apart, like the quality of bass. Too little negative feedback is big trouble for bass quality. How much is too little and how much is too much? I’ve never been impressed with zero negative feedback in an amplifier. A little bit of feedback, even as small an amount as 2dB to 4dB in one gain stage (out of three) is enough to keep the bass in line while not enough to do harm to the loveliness of the mids and highs. Too much is easy to identify. Think sibilants. You hear too much emphasis on sibilants? Chances are the amplifier you are listening to has way too much negative feedback. In fact, a good portion of what at one time was known in high-end land as "solid-state sound" was strictly an artifact of silly-large amounts of negative feedback. It is not entirely inaccurate to think of amps using a lot of negative feedback as the uptight conservative businessman of the audiophile world -- too inhibited to ever have a really good time. They are too controlled, too unforgiving, too dry, too emotionless, too uptight. They are certainly lower in total harmonic distortion than low-negative-feedback amps, but what does it matter if the music is as crisp and colorless as fall leaves in winter?

While zero negative feedback is too little, 10dB of global or even local (within a single gain stage) is often too much. Think 2dB to 6dB of local feedback for most amplifiers to do their thing with high levels of musicality across the entire musical spectrum. You can do "stupid amplifier tricks" playing with less or more feedback, but in the end, they all eventually sound "tricky" while the very moderate amount of feedback sounds like music. It’s typical for solid-state amplifiers to have 20dB to 60dB of negative feedback. Are those guys actually listening to what they are building?

There may very well be some wailing about my pronouncement that 2dB to 6dB of local negative feedback with no global negative feedback is "enough" coming from the amplifier manufacturer/designer community. Don’t trust them. If they think they need more feedback than that to get good sound, they just aren’t listening, or they don’t know how to resolve the problems that will crop up (sonic problems) when they eliminate most of the feedback they are used to using. That doesn’t mean my concept of the right amount of feedback is incorrect. It just means that some manufacturers/designers aren’t going to know how to incorporate that small of an amount of feedback into their products. The manufacturers that can build great-sounding solid-state (or tube) amps with low amounts of negative feedback without suffering muddiness of sound and woolly bass have a major sonic advantage that you will/can recognize once you have heard it.

Is having adjustable negative feedback a good idea? I have seen several tube amplifiers which have user adjustable negative feedback. On the surface, this seems like quite a worthwhile feature. It certainly is educational to hear what happens as you change the amount of feedback. However, once you begin trying different discrete resistors that are soldered into a negative-feedback loop -- well.... Let’s just say that the resistors in the negative-feedback loop are impressively obvious when changed, either in value, manufacturer or material. I cannot imagine any potentiometer added to the feedback loop would do anything but sound really bad compared to a single properly selected high-quality resistor. In fact, having heard how critical the resistor in the negative-feedback loop is, I can’t imagine a worse place to locate a potentiometer than in the negative-feedback loop. Compared to a good resistor, the best potentiometers sound quite bad. Use of a stepped attenuator might eliminate a lot of problems caused by sonic limitations of potentiometers. However, the negative-feedback loop is a very sensitive area of the circuit, I’m not sure if mechanical contacts in the stepped attenuator could ever be good enough to be sonically inconsequential in this location.

Yeah, this is driving me nuts. A friend of mine was nice enough to drop off his Pass Labs X350 amp again to compare to my Aragon Palladium monoblocks. Both put out very similiar power regardless of impedance, both are practically identical in SQ too from all the ABing I did tonight. The Aragon's are true differntial balanced monoblocks, the Pass Labs is a 0 feedback design supposedly which they advertise(Aragon doesnt state its a 0 feedback design)and is also a balanced design by nature if Im correct. And I cant tell the difference between the 2 for the life of me.

Aball thats what I was trying to say in other words.It does seem a tad slower and softer.Which to my ears is slighlty cloudy.I really don't understand the reason for having these settings.When the designer states for the most transparency leave it on the lowest settings.Then again maybe it has something to do with matching the preamp or cd player gain to the amplifier.I don't know ..Aball your the engineer how about shed some light on this.

I have used amps with feedback switches too (like the Unison Simply 2 and 4 tube integrateds) and I didn't find the soundstage "clouds" up really when i go to high feedback. I would say that it is more of softer and slower sound instead but I could hear the same background details in both with no difference in level. It was more of a mood change IMO. I about wore the switch out going back and forth and came to the conclusion that the difference was overall quite subtle. My brother couldn't hear the difference in a blind test but I could albeit just barely. I think the switch went between 6 dB and 12 dB. Pretty cool - I would like to find other amps with a toggle switch like that and listen again. ciao - Arthur

Thanks Edartford for the info.The Music Reference has 3 settings for feedback and the manual stated for best results to leave it on the lowest setting.It was very easy to hear the differences when changing from one setting to another.The more feedback the more the soundstage seemed to get clouded up.

Gmood1...Negative feedback just means that the amp output is compared with the input, with appropriate gain and phase compensation, and the resulting "error signal" is applied to the input (or at some intermediate stage) so as to reduce the error signal to zero (nearly). There is no fundamental reason why negative feedback is bad, but if an amp requires too much this probably means that the circuit is not too hot to begin with.

Tube amplifiers that use transformers must have negative feedback to get flat frequency response, quite apart from the issue of distortion. The widely used "ultralinear" configuration has taps on the output transformer specifically for the purpose of negative feedback.

Hmmm, Im gonna have to start a new thread on feedback. 0 feedback designs, and if 0 feedback is necessary onlly in the source if using xlr's or the opposite etc.

Good question Ritteri....well it's not an audible noise.I didn't notice it until I switched the the Mac out with the Monarchy.The Monarchy is supposed to be no feedback.And take also into account the wattage (monarchy)25 wpc verses (mac)300 wpc.Instantly I could hear more background noise..especailly in live recordings.Not hissing noises but people talking and laughing.There was just more ambience of the recording venue getting to my ears.Since then I have been ruined and only listen for amplifiers that can do the same thing.Not even my now removed Music Reference RM9 MKII which is a terrific tube amplifer had that kind of depth.I don't know the specs on feedback with my Adcom 585 but it must be very low because I can also hear these same attributes in it. Instead of just hearing people shouting in the audience you can hear their voices echoe off the walls of the venue.It's just easier for me to hear, when the singer turns his or her head away from the mic and what direction they turn.

Hope this gives you an idea!

I got a question for all of you on feedback. Some people say they can hear feedback in amps, others say they cant. What does negative feedback soundlike? Background noise? I know my cd player is a 0 feedback design, and I run all balanced xlr connections, plus my amps are true balanced designs too(but Im not sure if they are 0 feedback designs, probably not)but I cant hear any extraneous noise when music is playing or between passages or tracks. What am I listening for(if its even possible to detect it in my system)?

Gmood1 - Ok, here is another argument for you - LOL! ;)

I read a McIntosh white paper on the power guards and the distortion sensing circuit has a super high input impedance (order of 1 Gohm) which effectively takes it out of the circuit. Very clever use of JFETs.

The smooth, thick sound that McIntoshes have is probably due to fairly high negative feedback IMO. The Mc guys are all true electrical engineers so NFB is a requirement in their book (and mine too to some extent). The newer designs use less NFB than the older ones like our amps due to BJT improvements but nonetheless, it is a type of sound you have to like to appreciate, I realize. The upshot is that they are indestructible (especially with autoformers but I digress...) and have lower distortion than most amps out there.

Anyway, good system matching is most critical for hi-fi sound regardless of the equipement used. The best sound I have ever heard was a McIntosh MC602 (and C42) with Martin Logan Prodigys. Wow - I will never forget it. One day I will have Mcs and electrostats as the synergy was obvious in the first 3 seconds of music - it sounded like 600W of crystal clear tube amps.

Cheers and enjoy the music! Arthur

Thanks Ritteri for the advice.Actually I'am using Magnepans at home.I have a friend that owns the 100v.2s and I have spent many hours listening to them with different equipment.I see you use Voodoo aswell..these are some giant killer cables.And another good product thats overlooked because of it's price.I think I could change some minds about the Adcom gear when mated to Planars or Electrostatics.No one could deny it not sounding good when setup properly.Of course there will always be trade offs in something.I don't get the bass of the Paradigm or any other box speakers but I do gain clarity ,speed and inner detail with the Maggies.A trade off I'am willing to live with.

Gmood1: I take it your running Paradigm Reference series 100 floorstanders?? If you think those speakers are bright sounding, add some room treatments. Paradigm's can actually be very mellow and smooth sounding if you take care of all the first reflection points in your sound room.

You are right.. I checked Aball.. no argument.Maybe it's the powerguard or sentry monitor circuits they use in these models.I also listened to my 7106 on the 100v2s.And it was rolled off in comparison to the Adcoms and it did sound better because of this.The Paradigms can be bright when hooked to the wrong amp.So you also can use your own advice aswell.I sold an MX 132 to one of your fellow Brits..Mac makes good stuff.I enjoyed it just like every other amplifier I have owned ...sorry there is no perfect peice of equipment! But you already know I like having arguments with you! Heh ha hee

Enjoy the Mac.. Arthur and Happy Listening!

Gmood1: Your McIntosh MC7106 did not have autoformers. Sorry to break the bad news for your argument.

Also, don't forget about system synergy when you compare amps. The system you tried the component in is as critical to the sound description as the component itself.

Eldartford..that could be true .I have a soft spot for Maggies and Martin Logans.But I doubt the sounding better is due to price,it's more of system matching.Even the little Monarchy SM 70 for $350.00 smoked that Mac that I used to own.I'am one of the few audiophiles that will admit...Even if I payed more for one product doesn't give me an excuse to think or hope it sounds better than one that cost less.I have already proved this in my own system and no longer look for the flashy gear but for what sounds true to my ears.If CC Poon put his Monarchy products in a chrome chassis ,he could sell them at almost triple the price.And no one would be the wiser!

I wouldnt compare a basic adcom amp with an Aragon. But the GFA5802 is regardless of price a great amplifier. Nelson Pass designed the GFP-750 preamp, but the GCD-750 cd player and the GFA5802 I dont think he can take credit for.

If the toroidal transformers are stacked that could explain the disagreement.

By the way, think that the Aragon amp costs more than twice the Adcom price, so it ought to be better.

My Adcom 5503 (like a 5500 but with three channels) is hooked up to Maggies. Although Maggies are often called low impedance speakers, they actually are a very uniform 4 ohms regardless of frequency, which makes them an "easy" load for the power amp. Maybe that's why you can get good results with a less exotic (expensive) amp. (But they do like lots of watts).

I'm the owner of the Aragon 4004 MK II with current pictures and actaully if I remember there are two transformers, stacked. As I look close at the photos I took I'm even more sure of it. I too have owned an Adcom 555 and do prefer the Aragon sound to the Adcom. Just an opinion. My favorite is my Bel Canto EVO 4, thus the Aragon sale. BTW the Adcom sold for $350.00 and all the 4004's on AudiogoN are at $750.00. I'm not sure where it'll finally sell at but I'll keep it for a hood ornament before I go down to Adcom prices.

Jsujo...I think your on to something. My Mac did have the autoformers.Maybe this is what I was hearing.It was great for speaker protection but not for sound quality! I admit I don't like the sound of Adcoms on 100v2 Paradigms but hooked up on some Maggies it's a different story!

Eldartford,

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3055794170&category=39783#ebayphotohosting

seems the price is getting pretty darn reasonable on that new amp you were talking about.

Actually i have no idea of the benefit of the dual mono design over the stereo design while sharing the same chasis and ac plug. I only brought it up as comparing the 2 amplifiers in question. Common sense tells me there would seem more than likely to be a better seperation between channels however small that might be. As to sonic values i have no clue. Another reason for the thread :)

I think only the 5802 was designed by Pass?

I used to own an Aragon 8002, and it definitely sounded better than my friend's Adcom 555 and 5000 (the replacement for the 555?).

And what is this with the dual mono? The left and right channels of the amp shared on the chassis, transformer and powerplug. Does this still qualify as dual mono?

Which amps in the Adcom line were designed by Nelson Pass?
I had the GFA-5500 and I enjoyed quite a bit...The McIntosh amps that do not have Autoformers, I dont believe they have that "Mac" sound...

Kool39...The photo I saw of a for sale 4004 showed one toroidal transformer. Pop the cover and take a look, or admit it doesn't matter :)

Actaully yes you are correct. I think the 4004 has dual 900kVA transformers. THe 8008BB has dual 1.1kVA transformers. The Palladiums each have a 2000kVA transformer.

Ritteri, I have never had my top off so i was just going by this quote from Mondial Designs'
"The true replacement for the 4004 was the 8008BB. However, the 8008 BB also incoporated 50% more output transistors, twice as much power supply capacitance, and the balanced input stage. The difference between the 8008ST and 4004 is that the 8008ST used a single, "dual-wound" transformer for the power supply while the 4004 has the separate transformers. The 8000 series amplifiers also added the DC servo circuit for flat operation down to 5 Hz."

Adam Gershon
Mondial Designs

Kool39: The Aragon 4004 uses a single toroidal with seperate windings.

I like the two following quotes together:

"It sounds like Mcintosh tried to make this amp sound like tubes.Which was not a very good idea. " AND "somewhat resembles tubes (more "musical")."

Personally, I would rather have music than sounds. To me and my friend, McIntosh was more appealing than the 555. I guess we just like music. I was simply reciting my story, as you did.

As for the Carver, I don't know it. There are several amps in the $600-900 range I would like to hear but haven't yet. I am not permanently sold on McIntosh but for now, it is the most musical I have heard - and that is what I am in this for. Cheers! Arthur

Aball...What do you know about the Carver 1600? Its distortion specs are quite respectable, especially when measured well below the 600 watt level, which, of course, is where it will operate. I have not seen anything but good words about this amp, which sells for about $900.

Aball and Kool139....I think that this FAQ writeup from Adcom, who uses both mosfets and bipolar output devices is a fair description.
QUOTE
My amplifier seems to run hot. Is this a problem?

Probably not. Most Adcom amplifiers use output devices called "MOSFETs" (which stands for metal oxide semiconductor field effect transistor, if you're curious). We've chosen these devices for their superb 'musicality'. They do, however, run hotter than more conventional bipolar transistors. We have designed our amplifiers with large 'heat sinks' made up of aluminum fins that dissipate excess transistor heat into the air. Just make sure you provide adequate room for ventilation as opposed to stacking other equipment directly on top of your amplifier.

What's the difference between your old amps and your new ones?
Well, the biggest difference goes back to MOSFETs again. Most of our newer "4 number" amplifiers (i.e. the GFA-5802) use MOSFETs while all our older "3 number" amplifiers (i.e. the GFA-555), used bipolars.

So, are bipolar amplifiers bad?
Actually bipolars have some advantages. As noted above, they produce less heat for a given power output. This makes them suitable for more compact components or for multi-channel, home theater amplifiers. As such, we have chosen to use them in our custom oriented amplifiers, the GFA-5002 and the GFA-5006, where size can be at a premium, and in our multi-channel, home theater amplifiers, the GFA-7500, GFA-7400 and GFA-7300.

Bipolars can have a very detailed, up front sound quality, and with our 2 decades of experience in getting the most out of these devices, we think you'll find that the bipolar's inherent immediacy is nicely tempered with circuit touches that let you hear a rare level of musical integrity.

END QUOTE

Of course there is a lot more to amp design that the type of transistor used. The mosfet requires less complex drive circuitry, and because of their thermal characteristics multiple devices can be more successfully paralleled, as is usually necessary for power amps. Perhaps I should have said that the distortion produced by mosfet circuit is typically low and the spectrum of harmonics somewhat resembles tubes (more "musical"). This last point is my recollection of Hafler literature when they introduced the use of mosfets to the audio world. Hafler still uses and touts mosfets. I haven't made a survey of the entire industry.

I only looked at a photo of a 4004, and it only had one transformer. If a power supply is properly designed it doesn't need to be separate for each amp. Use of two transformers is probably a practical choice, because one would be heavy to handle, and hard to mount on a chassis.
Actually, IMHO, and based on my own experience with monoblocks and multichannel amps, the greatest advantage of the mono approach is to avoid having an amp that requires a forklift to move around. Electronic advantages are insignificant.

Talk about driving difficult loads take a look at this link and the first amp on their recommended list. http://www.apogeespeakers.totalserve.co.uk/scintilla.htm

Let me rephrase "dual mono" design.

Eldartford, the Aragon 4004 mkII does indeed use seperate transformers. IT is a true mono design.

Well Arthur I have owned the Mcintosh 7106 and compared to the 585 adcom. I think it would sound thin.Why ..well the Mac has a thickness to it.It sounds like Mcintosh tried to make this amp sound like tubes.Which was not a very good idea. The 585 Adcom is more transparent,better bass and voices are more distinguishable.This amplifier sounds like whatever you stick in the front of it.Nothing more.. nothing less.My 7106 was slow in comparison..maybe because of the current limitng circuits not really sure. The Mac retailed for 3500.00 the Adcom $1200.00 but you can't tell this when doing a fair comparison.The 7106 couldn't dream of handling the loads this amplifier can.A person has to decide if he wants a neutral amplifier or buy something to cover another flaw in his system.I'll take the neutral amplifier and work on the flaws.The highs are rolled off on some of the SS Macs.. this would give someone the impressions that another amplifier is bright.But before I point a finger at the amp I would look at my speakers and cables.Not bashing the the Mac but it is definitely not a neutral amplifier.

Kool39 it's cool everybodys got a favorite.I have no problem with that.
I have nothing against Aragon...so to each his own.I like some mosfets amplifiers , some bipolars and some tubes.But the bipolars are supposed to have 1/3 the distortion of mosfets.And to my ears this holds true.It's definetly a cleaner sound but I still love the Monarchys,and think their a great buy!Especially when paired with some fairly efficient speakers.

Happy Listening!

One point I want to make (I have done research in this) about bipolar vs. MOSFET is that the notion "bipolar to mosfets because of inherently better distortion characteristics" isn't quite right. Distortion (due to nonlinearity - not noise which is design related) is lower in BJTs than in MOSFETs. This is why most makers today only use BJTs in output stages. In the near future, with recent developments in lateral MOSFET doping, this may not be the case anymore but for now, the BJT is the undisputed champ for linearity. One of the main advantages of going wtih MOSFET is that you can lower the amount of feedback before instability ensues. Design is a matter of weighing the trade-offs....

As for Class D, there is still some work to be done before all digital kills off analog IMO. There are many issues still to be resolved and talk about non-linearities!! I will stop here because I will get carried away with this one. Arthur

Kool39...My observation about "way more musical" was general in nature, interpreting Johngalt47's observation.

With regard to the particular Aragon amp: no I do not have experience with it. From what I see and read it appears to be similar in concept to Adcom products, and I am sure that I would be quite happy with it. (But how do prices compare between comparable models?) I only see one power transformer, so I can't agree with the "dual mono" description. Adcom and some others went from bipolar to mosfets because of inherently better distortion characteristics, but bipolar can be good, and Adcom has returned to bipolar for their multichannel HT products because of lower heat dissipation.

My next amp, if there is one, will be digital. Maybe the Carver ZR 1600. By all accounts it will blow all this stuff away, for less money.

A friend of mine has an Adcom 555 mk2 and he brought it over to my house a couple months ago because he wanted to hear it power my Paradigm Reference 100.2 (his stereo got piece-mealed when he moved and is still that way). He just had it checked out and it was ready for a test. I took my McIntosh MC7100 out and put his amp in. We listened to the same music on both and the Adcom was definately lean, a little bright, and somehow not as extended in either direction as my McIntosh. We were both surprised. It also started clipping at the same point as my amp desite the Adcom power being rated much higher (gain is similar). He left disappointed and last I heard, it is up for sale.... Anyway, depends on the type of sound you like and your system synergy, but in our test and in our opinion, the Adcom failed. Audition if you can. I don't know the 4004 but I auditioned the 2005 with a Stage One and it sounded very good with Definitive Tech speakers. Good luck! Arthur

Gmood1, As I look closer at Johngalt47 reply I noticed that he wasnt even sure of the model number of the adcom.
I stand corrected.

ELdartford, I was looking over your past threads and my wife looks over at me and says what is so funny. I like your humour. Good Stuff!

Didnt realize i picked such a touchy subject. LOL

Gmood1, I really think Johngalt47 was just stating his real life comparison between the two. And he stated he wasnt sure if the amp or if other components are what made the the biggest difference. Also he was just giving his opinion on the adcom 555mk II which he had in his home so thats a pretty good test. Aragon 4004 mkII also uses a bipolar design.

Eldartford, I understand that you like adcom and own them but have you actually compared it to an aragon 4004 mkII in your home? I see that you drive maggies with 5503's. Really the 555mk II and 5503 are totally different animals. The older model uses bipolar design and the newer uses mosfets. So i am not really sure how you are comparing the 2 amps i requested information about. I do notice you talk alot about the 5503 handling a tough load which you state at being 350wpc/4 ohm load. Well one thing about the aragons they are quite noted for handling tough loads. The aragon 4004 mk II is a true mono design amplifier which doubles down from 8 to 4 and again to 2 ohms. Also with the true mono design i would imagine the stereo seperation between the 2 channels would also highly have to favor the aragon.

But i am not here to slam adcom i think they make good products at good prices. My initial thread was just to find out some comparisons that people have done in their own homes with both products. Aragon just happened to be the favored here from folks that owned both.

Happy Listening!

You know some of us have to make ourselves feel better when we spend more on some of this stuff.Adcom 500 series cheap sound ..I doubt it! You will find the same transistors in some Rowlands,Pass,and Mark Levinsons. I guess they sound cheap too! Or you like paying for a face plate ..which I can't seem to hear to save my life.

Aragon. Owner of a pair of modified Palladium 1K's. Ive been happy since day one. Adcom's best amplifer though the GFA5802 which I feel isnt too shabby of an amp for the price would be a good comparison again a 4004 I think. Both have a similiar used value too dont they?

"Way more musical" is a nice way of saying it has more harmonic distortion. Ok if that's what you like.

I own the Aragon and used to have an Adcom although I can't remember if it was that model or not. In any case, the Aragon was way more musical. The Adcom sounded "cheap" to me. However, the other components were upgraded at the same time (my house was burglarized) so it is not an apples to apples comparison.